Palladium(II) derivatives of alkylsulfanyl substituted thiophenes as precursors of inorganic polymers: Spectroscopic, electrochemical investigations and X-ray crystal structure of trans-PdCl2[3-(butylsulfanyl)thiophene]2

Palladium(II) complexes with two thiophene derivatives bearing alkylsulfanyl chains, i.e., 3-(n-butylsulfanyl)thiophene and 4,4′-bis(n-butylsulfanyl)-2,2′-bithiophene, are synthesised and spectroscopically and electrochemically characterised. The molecular structure of PdCl₂[3-(n-butylsulfanyl)thiophene]₂ was determined by X-ray analysis. The properties of the complexes have been compared with those of PdCl₂[3,3′-bis(n-butylsulfanyl)-2,2′-bithiophene] and of a conductive polymer partially coordinated with Pd(II), previously synthesised by us. We found that Pd(II) ions can coordinate sulfanyl sulfur atoms both in cis and trans configuration, leading to a reticulate material, where some kind of interchain bridging may be reasonably supposed to enhance the bulk conductivity.     

JUST (Java User Segmentation Tool) for semi-automatic segmentation of tomographic maps

We are presenting a program for interactive segmentation of tomographic maps, based on objective criteria so as to yield reproducible results. The strategy starts with the automatic segmentation of the entire volume with the watershed algorithm in 3D. The watershed regions are clustered successively by supervised classification, allowing the segmentation of known organelles, such as membranes, vesicles and microtubules. These organelles are processed with topological models and input parameters manually derived from the tomograms. After known organelles are extracted from the volume, all other watershed regions can be organized into homogeneous assemblies on the basis of their densities. To complete the process, all voxels in the volume are assigned either to the background or individual structures, which can then be extracted for visualization with any rendering technique. The user interface of the program is written in Java, and computational routines are written in C. For some operations, involving the visualization of the tomogram, we refer to existing software, either open or commercial. While the program runs, a history file is created, that allows all parameters and other data to be saved for the purposes of comparison or exchange. Initially, the program was developed for the segmentation of synapses, and organelles belonging to these structures have thus far been the principal targets modeled with JUST. Since each organelle is clustered independently from the rest of the volume, however, the program can accommodate new models of different organelles as well as tomograms of other types of preparations of tissue, such as citoskeletal components in vitreous ice.     

Interaction of mildronate with the mitochondrial carnitine/acylcarnitine transport protein

The interaction of mildronate [3-(2,2,2-trimethylhydrazine) propionate] with the purified mitochondrial carnitine/acylcarnitine transporter reconstituted in liposomes has been studied. Mildronate, externally added to the proteoliposomes, strongly inhibited the carnitine/carnitine antiport catalyzed by the reconstituted transporter with an IC(50) of 560 muM. A kinetic analysis revealed that the inhibition is completely competitive, that is, mildronate interacts with the substrate-binding site. The half-saturation constant of the transporter for external mildronate (K(i)) is 530 muM. Carnitine/mildronate antiport has been measured as [(3)H]carnitine uptake into proteoliposomes containing internal mildronate or as [(3)H]carnitine efflux from proteoliposomes in the presence of external mildronate, indicating that mildronate is transported by the carnitine/acylcarnitine transporter and that the inhibition observed was due to the transport of mildronate in the place of carnitine. The intraliposomal half-saturation constant for mildronate transport (K(m)) has been determined. Its value, 18 mM, is much higher than the external half-saturation constant (K(i)) in agreement with the asymmetric properties of the transporter. In vivo, the antiport reaction between cytosolic (administered) mildronate and matrix carnitine may cause intramitochondrial carnitine depletion. This effect, together with the inhibition of the physiological transport, will lead to impairment of fatty acid utilization.     

Detection of Treponema denticola in root canal systems in primary and secondary endodontic infections. A correlation with clinical symptoms

AIM: The aim of the study was to investigate the presence of Treponema denticola in primary and secondary root-infected canal systems with periapical pathology and correlations with clinical signs and symptoms. METHODOLOGY: Endodontic samples were obtained from canals of 102 teeth: 79 had primary endodontic disease and 23 secondary endodontic disease. For each tooth, clinical data including symptoms and X-ray appearance were examined. The presence of T. denticola biological samples from the root canal space was detected by a PCR assay. RESULTS: T. denticola was detected in 24 out of the 79 teeth with primary infection and in 8 out of the 23 teeth with secondary infection. Teeth with specific clinical symptoms were frequently associated with T. denticola presence inside the root canal system. CONCLUSIONS: The presence of T. denticola in root canal system in association with specific clinical signs and symptoms of endodontic disease strongly suggests that this spirochete might play a critical role in the pathogenesis of the acute infection and rapid bone tissue alterations in both primary and secondary endodontic infections.     

Low avidity antibody: a reliable method to diagnose a recent HIV-1 infection

Standard serological tests (both EIA and Immunoblotting) have reached high levels of sensitivity and reproducibility, but do not indicate whether infection is recent or longstanding. Since many patients with HIV-1 infection are not usually diagnosed until symptom presentation, the possibility to distinguish between acute and chronic infection has become increasingly important for the purposes of therapeutic decision-making, partner notification and epidemiological surveillance. We evaluated a guanidine-based-antibody-avidity assay in a selected group of recent (within six months from seroconversion) and chronic (more than forty eight months) HIV-1 infections in an attempt to shed more light on the significance of the avidity index in establishing the time of infection. Sera from newly infected individuals showed a low mean avidity index (ranging from 0.35 to 0.60 with a standard deviation 0.09) at baseline and a clear increasing value at the following times of observation. Our data showed that an avidity index <0.70 might be presumptive of infection occurring within 9 months. Avidity index levels might distinguish between acute and chronic infection. The method is semi-automated, inexpensive and easy to perform, and estimates the time elapsed from seroconversion, thereby identifying a recent infection.     

Non-organ-specific autoantibodies in renal transplant recipients: relation to BK virus infection

Polyomavirus BK reactivation is common in renal transplant recipients and may cause nephropathy with significant graft dysfunction. The induction of anti-double stranded DNA (anti-dsDNA) antibodies by BKV has been described in experimental animals and during primary infection, and has been implicated in the pathogenesis of systemic lupus erythematosus. This study evaluated the occurrence of anti-dsDNA antibodies and non-organ-specific autoantibodies (NOSA) by indirect immunofluorescence before transplantation and at 3 and 6 months post-transplantation in 90 renal transplant recipients and the association with BKV reactivation, demographic and clinical features. Moreover, the relation to HCMV infection, as detected by pp65-antigenemia, was also evaluated. Post-transplantation NOSAs were present in 23/90 (25.6%) and anti-dsDNA antibodies in 17/90 (18.9%). BK viremia was detected in at least one serum sample in 22 patients: 9 anti-dsDNA antibody-positive vs 13 negative (p<0.01). No significant correlation between the occurrence of NOSAs and anti-dsDNA antibodies and demographic and clinical features was found. No significant association with pp65-antigenemia-positivity was found, although antigenemia was positive in 6/23 NOSA-positive patients (26.1%). Although a relation seems to exist between BKV and the occurrence of anti-dsDNA antibodies in renal transplant patients, the lack of correlation with other epidemiological and clinical features does not allow any conclusion. The role of autoimmune response in this context and the relation with other patient-related factors and infectious agents should be further investigated.     

Vegetation at the Limits for Vegetation: Vascular Plants, Bryophytes and Lichens in a Geothermal Field

The effects of the chemical and physical factors associated with geothermal activity on plant community structure and composition were investigated in one of the largest geothermal fields of central Italy. The study site was located in the geothermal area of Sasso Pisano – Monte Rotondo Marittimo, Southern Tuscany. The percentage cover of all vascular plant, bryophyte and lichen species was estimated within 119 circular plots of 0.25 m². For each plot the soil pH, soil temperature, slope, aspect, incident radiation, soil nitrogen and carbon contents were also quantified. Two vascular plants, Calluna vulgaris and Agrostis castellana, were found to be the most widespread species tolerating the harshest conditions in terms of low soil pH and high soil temperature. The most widespread cryptogam species was Hypnum cupressiforme. Spatially autoregressive models showed that a proportion of about 41–51% of the variance in species richness of one group of plants (vascular or cryptogamic plants) could be modelled by using three or four uncorrelated environmental factors respectively (soil temperature, soil nitrogen and soil C/N ratio and these three plus incident radiation). For the total number of species (vascular and cryptogamic plants), the variance explained by the same three uncorrelated variables was about 57%. This study evidenced a strong environmental control of community composition and species richness, in a site subjected to extreme soil values of soil pH and temperature. The dominance of vascular over cryptogamic vegetation in this geothermal site can be explained by the combined effects of geothermal stress (low soil pH and high soil temperature) with the summer drought typical of the Mediterranean climate.     

Animal xenodiversity in Italian inland waters: distribution, modes of arrival, and pathways

The paper provides a list of the non-indigenous animal species occurring today in Italian inland waters. Xenodiversity was found to amount to 112 species (64 invertebrates and 48 vertebrates), which contribute for about 2% to the inland-water fauna in Italy. Northern and central regions are most affected, and Asia, North America, and the rest of Europe are the main donor continents. The large majority of non-indigenous species entered Italy as a direct or indirect effect of human intervention. A difference between invertebrates and vertebrates was found for their mode of arrival (unintentional for invertebrates and intentional for vertebrates). Accidental transport, in association with both fish (for aquaculture or stock enhancement) and crops, has been the main vector of invertebrate introductions, whereas vertebrates were mostly released for stocking purposes. Overall stock enhancement (47.92%) and culture (37.5%) prevailed over the other pathways. Seventeen and 7 species of our list are included among the 100 worst invasive species of Europe (DAISIE) and of the world (IUCN), respectively. For some (but not all) non-indigenous species recorded in Italy the multilevel impact exerted on the recipient communities and ecosystems is known, even if rarely quantified, but knowledge on their chronic impact is still missing. Additional research is needed to provide criteria for prioritizing intervention against well established invaders and identify which new potential invader should be targeted as “unwanted”.     

Organization of the pronephric kidney revealed by large-scale gene expression mapping

Background

The pronephros, the simplest form of a vertebrate excretory organ, has recently become an important model of vertebrate kidney organogenesis. Here, we elucidated the nephron organization of the Xenopus pronephros and determined the similarities in segmentation with the metanephros, the adult kidney of mammals.

Results

We performed large-scale gene expression mapping of terminal differentiation markers to identify gene expression patterns that define distinct domains of the pronephric kidney. We analyzed the expression of over 240 genes, which included members of the solute carrier, claudin, and aquaporin gene families, as well as selected ion channels. The obtained expression patterns were deposited in the searchable European Renal Genome Project Xenopus Gene Expression Database. We found that 112 genes exhibited highly regionalized expression patterns that were adequate to define the segmental organization of the pronephric nephron. Eight functionally distinct domains were discovered that shared significant analogies in gene expression with the mammalian metanephric nephron. We therefore propose a new nomenclature, which is in line with the mammalian one. The Xenopus pronephric nephron is composed of four basic domains: proximal tubule, intermediate tubule, distal tubule, and connecting tubule. Each tubule may be further subdivided into distinct segments. Finally, we also provide compelling evidence that the expression of key genes underlying inherited renal diseases in humans has been evolutionarily conserved down to the level of the pronephric kidney.

Conclusion

The present study validates the Xenopus pronephros as a genuine model that may be used to elucidate the molecular basis of nephron segmentation and human renal disease.