bluuebunny/crossref_metadata_2025 huggingface dataset:
Steroids, triterpenoids and molecular oxygen
Authors: Summons Roger E , Bradley Alexander S , Jahnke Linda L , Waldbauer Jacob R
Published: May 2006

There is a close connection between modern-day biosynthesis of particular triterpenoid biomarkers and presence of molecular oxygen in the environment. Thus, the detection of steroid and triterpenoid hydrocarbons far back in Earth history has been used to infer the antiquity of oxygenic photosynthesis. This prompts the question: were these compounds produced similarly in the past? In this paper, we address this question with a review of the current state of knowledge surrounding the oxygen requirement for steroid biosynthesis and phylogenetic patterns in the distribution of steroid and triterpenoid biosynthetic pathways.

The hopanoid and steroid biosynthetic pathways are very highly conserved within the bacterial and eukaryotic domains, respectively. Bacteriohopanepolyols are produced by a wide range of bacteria, and are methylated in significant abundance at the C2 position by oxygen-producing cyanobacteria. On the other hand, sterol biosynthesis is sparsely distributed in distantly related bacterial taxa and the pathways do not produce the wide range of products that characterize eukaryotes. In particular, evidence for sterol biosynthesis by cyanobacteria appears flawed. Our experiments show that cyanobacterial cultures are easily contaminated by sterol-producing rust fungi, which can be eliminated by treatment with cycloheximide affording sterol-free samples.

Sterols are ubiquitous features of eukaryotic membranes, and it appears likely that the initial steps in sterol biosynthesis were present in their modern form in the last common ancestor of eukaryotes. Eleven molecules of O2are required by four enzymes to produce one molecule of cholesterol. Thermodynamic arguments, optimization of function and parsimony all indicate that an ancestral anaerobic pathway is highly unlikely.

The known geological record of molecular fossils, especially steranes and triterpanes, is notable for the limited number of structural motifs that have been observed. With a few exceptions, the carbon skeletons are the same as those found in the lipids of extant organisms and no demonstrably extinct structures have been reported. Furthermore, their patterns of occurrence over billion year time-scales correlate strongly with environments of deposition. Accordingly, biomarkers are excellent indicators of environmental conditions even though the taxonomic affinities of all biomarkers cannot be precisely specified. Biomarkers are ultimately tied to biochemicals with very specific functional properties, and interpretations of the biomarker record will benefit from increased understanding of the biological roles of geologically durable molecules.
The analysis of the homoerotic and the pursuit of meaning
Authors: Miller Barry
Published: May 2006

Abstract:  This paper explores the dynamic tension between an evolving collective phenomenon and the nature of analytic process. Specifically, the focus will be erotic experiences which acquire a meaning through the culture at large, a meaning that may not be supportable when that material is subjected to psychological analysis. This stimulates a conflict between the symbolic attitude and the cultural perspective of the time. While the struggle between the individual and collective consciousness always emerges in analysis, the subject of same‐gender sexual relations has become such a controversial and divisive issue in the current political environment that views toward homosexuality demand powerful allegiances and identification with either historic or contemporary ideas. People now identify as ‘gay’ and tend to see themselves as something akin to a race or perhaps alternative gender. Sexuality and relationship between same gendered people tends to be viewed through the lens of civil rights and the undeniable need for social equality. In this far‐reaching and expanding collective phenomenon, psychology, in its support of human rights and accommodation to emerging trends, may be diminished in its capacity to pursue the meaning inherent in these human experiences. The position developed in this paper is that psychological experience, whether in the imaginal realm, dreams or personal consciousness, must be available for full analysis. Clinical experience and dreams are used to amplify this challenge to dynamic analytic practice.
Queering gender: anima/animus and the paradigm of emergence
Authors: McKenzie Susan
Published: May 2006

Abstract:  An exploration into the world of the queer others of gender and sexuality moves us beyond the binary opposition of male/masculinity and female/femininity in our understanding of gender and expands the meaning of gender and sexuality for all humans. A revision of Jungian gender theory that embraces all genders and sexualities is needed not only to inform our clinical work but also to allow us to bring Jungian thought to contemporary gender theory and to cultural struggles such as gay marriage.

The cognitive and developmental neurosciences are increasingly focused on the importance of body biology and embodied experience to the emergence of mind. In my exploration of gender I ask how gender comes to be experienced in a developing body and how those embodied gender feelings elaborate into a conscious category in the mind, a gender position.

My understanding of emergent mind theory suggests that one's sense of gender, like other aspects of the mind, emerges very early in development from a self‐organizing process involving an individual's particular body biology, the brain, and cultural environment. Gendered feeling, from this perspective, would be an emergent aspect of mind and not an archetypal inheritance, and the experiencing body would be key to gender emergence.

A revised Jungian gender theory would transcend some of the limitations of Jung's anima/animus (A/A) gender thinking allowing us to contribute to contemporary gender theory in the spirit of another Jung; the Jung of the symbolic, the mythic, and the subtle body. This is the Jung who invites us to the medial place of the soul, bridging the realm of the physical body and the realm of the spirit.
Prospective analysis of treatment outcome and prognostic factors in patients with T‐cell lymphomas treated by CEOP‐B: single institutional study
Authors: Sung Hwa Jung , Kim Seok Jin , Seo Hee Yun , Sul Hye Ryoung , Choi Jong Gwon , Choi In Keun , Park Kyong Hwa , Oh Sang Cheul , Seo Jae Hong , Choi Chul Won , Kim Byung Soo , Shin Sang Won , Kim Yeul Hong , Kim Jun Suk
Published: May 2006

The important prognostic factors were evaluated for T‐cell non‐Hodgkin lymphoma (NHL) patients in a prospective study using the CEOP‐B protocol [a modified cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP)‐like regimen that uses epirubicin instead of doxorubicin with the addition of bleomycin]. Fifty‐two patients were enrolled in the study. The overall response rate was 63·5%. The median progression‐free survival (PFS) and median overall survival (OS) was 18·0 and 39·5 months respectively. The most common toxicity was neutropenia. The factors related to poor outcome were a high International Prognostic Index (IPI) and a high ‘B’ score (bone marrow involvement, B symptoms, bulky disease). We developed a new prognostic model, namely the Prognostic Group for T cell NHL (PGT) that included four groups: PGT1 (low IPI/low B score), PGT2 (low IPI/high B score), PGT3 (high IPI/Low B score) and PGT4 (high IPI/Low B score). OS and PFS (not reached, 48 months) in the PGT1 group were significantly longer than those (11·5 and 4·8 months) in PGT2. The same result was observed in the PGT3 and PGT4 groups. The CEOP‐B regimen was moderately active and tolerable for T‐cell NHL patients, and the PGT system might be useful for the prediction of long‐term survival of T‐cell NHL patients.
Abnormally short activated partial thromboplastin time values are associated with increased risk of recurrence of venous thromboembolism after oral anticoagulation withdrawal
Authors: Legnani Cristina , Mattarozzi Silvia , Cini Michela , Cosmi Benilde , Favaretto Elisabetta , Palareti Gualtiero
Published: May 2006

This study prospectively evaluated the relationship between activated partial thromboplastin time (aPTT) and risk of venous thromboembolism (VTE) recurrence after oral anticoagulant (OA) withdrawal in patients with a previous unprovoked VTE event. Six hundred twenty‐eight patients (331 males; median age: 67 years) were followed after OA interruption (mean follow‐up = 22 months). Three to four weeks from OA discontinuation patients were given a complete thrombophilic work‐out, including aPTT (automated aPTT). Recurrent symptomatic VTE events (objectively documented) occurred in 71/628 (11·3%, 6·8/100 person‐years) patients. The VTE recurrence rate was 17·5% and 7·5% in patients with aPTT in the lower (ratio ≤0·90) and in the upper (ratio >1·05) quartiles. The recurrence risk was more than twofold higher in patients with ratio ≤0·90 versus those of the reference category [Relative risk (RR): 2·38 (95% confidence interval (CI): 1·18–4·78)]. As expected, the increase in recurrence risk disappeared after adjustment for factor VIII, IX and XI levels [RR: 1·74 (95%CI: 0·43–2·76)]. In contrast, the risk was persistently increased in patients with a ratio ≤0·90 [RR: 2·07 (95%CI: 1·02–4·18)] after adjustment for age, gender and d‐dimer level. The aPTT predictive value was independent of the presence of inherited thrombophilic alterations. In conclusion, abnormally short aPTT values are associated with a significantly increased risk of VTE recurrence.
Essential elements of implementing a system of concurrent planning
Authors: Frame Laura , Berrick Jill Duerr , Coakley Jennifer Foulkes
Published: May 2006

In efforts to preserve foster children’s biological families and to promote the formation of alternative families in some situations, legislative efforts to promote ‘permanency’ have been gaining pace since the late 1990s. One policy and practice tool, concurrent planning (CP), simultaneously allows for the pursuit of reunification and adoption. This article examines six counties in California (USA) and their efforts towards implementation of the components of CP. Researchers used qualitative methods to explore policies and practices of CP. Key informants include social workers, social work supervisors, attorneys and judges. The study identifies and describes seven elements determined to be essential to the complete and successful implementation of CP. Implications for agency practice and family outcomes are discussed.
FAMILY LIFE WITH A HANDICAPPED CHILD: THE PARENTS SPEAK
Authors: LONSDALE GILL
Published: May 2006

Summary This paper summarizes the main points made in 60 interviews with parents of handicapped children living in one City. Its aim is to provide information from the consumers of the professional services which may have relevance for future planning.
WORKING WITH PARENTS OF MENTALLY HANDICAPPED CHILDREN ON A LONGTERM BASIS*
Authors: HARRIS JOHN
Published: May 2006

Summary This paper presents some of the problems which have arisen in working with one group of parents over a period of 4.5 years.
Impacts of climate warming and habitat loss on extinctions at species' low‐latitude range boundaries
Authors: FRANCO ALDINA M. A. , HILL JANE K. , KITSCHKE CLAUDIA , COLLINGHAM YVONNE C. , ROY DAVID B. , FOX RICHARD , HUNTLEY BRIAN , THOMAS CHRIS D.
Published: May 2006

Polewards expansions of species' distributions have been attributed to climate warming, but evidence for climate‐driven local extinctions at warm (low latitude/elevation) boundaries is equivocal. We surveyed the four species of butterflies that reach their southern limits in Britain. We visited 421 sites where the species had been recorded previously to determine whether recent extinctions were primarily due to climate or habitat changes. Coenonympha tullia had become extinct at 52% of study sites and all losses were associated with habitat degradation. Aricia artaxerxes was extinct from 50% of sites, with approximately one‐third to half of extinctions associated with climate‐related factors and the remainder with habitat loss. For Erebia aethiops (extinct from 24% of sites), approximately a quarter of the extinctions were associated with habitat and three‐quarters with climate. For Erebia epiphron, extinctions (37% of sites) were attributed mainly to climate with almost no habitat effects. For the three species affected by climate, range boundaries retracted 70–100 km northwards (A. artaxerxes, E. aethiops) and 130–150 m uphill (E. epiphron) in the sample of sites analysed. These shifts are consistent with estimated latitudinal and elevational temperature shifts of 88 km northwards and 98 m uphill over the 19‐year study period. These results suggest that the southern/warm range margins of some species are as sensitive to climate change as are northern/cool margins. Our data indicate that climate warming has been of comparable importance to habitat loss in driving local extinctions of northern species over the past few decades; future climate warming is likely to jeopardize the long‐term survival of many northern and mountain species.
Eminent role of ICOS costimulation for T cells interacting with plasmacytoid dendritic cells
Authors: Janke Marko , Witsch Esther J. , Mages Hans W. , Hutloff Andreas , Kroczek Richard A.
Published: May 2006

CD4+ CD45RO+ T cells could mature freshly isolated human plasmacytoid dendritic cells (PDC) in a superantigen‐driven culture in a similar way to recombinant interleukin‐3 (IL‐3). Mature PDC expressed significantly higher levels of inducible costimulator ligand (ICOS‐L), but similar levels of CD80 and CD86, when compared to mature monocyte‐derived DC (moDC). We therefore directly compared the capacities of mature PDC and moDC to activate T cells. A similar T helper type 1 (Th1)/Th2 pattern of cytokines was generated in both systems, but significantly higher levels of IL‐3, IL‐4 and IL‐10 were induced by PDC. In T cells interacting with PDC, the ICOS/ICOS‐L costimulatory pathway played a pre‐eminent role in the generation of IL‐3 and IL‐10, CD28 was central to the induction of IL‐2, and both pathways were equally important for the generation of other cytokines. In cocultures with moDC, the CD28 pathway was dominant over ICOS under all circumstances, except for the ICOS‐mediated release of IL‐10. In general, our data demonstrate an eminent role of ICOS in the interaction of T cells with PDC, and thus modify the current paradigm of CD28 dominance for the costimulation of T cells interacting with professional antigen‐presenting cells. In particular, our data highlight the role of ICOS in the generation of IL‐3, a factor central to the biology of human PDC.
PS80 interferes with the antiallergic effect of Cry‐consensus peptide, a novel recombinant peptide for immunotherapy of Japanese cedar pollinosis, at very low concentration through modulation of Th1/Th2 balance
Authors: Kozutsumi Daisuke , Tsunematsu Masako , Yamaji Taketo , Murakami Rika , Yokoyama Minehiko , Kino Kohsuke
Published: May 2006

Polysorbate 80 (PS80 or Tween‐80) is often used as an additive to promote the rapid solubilization of pharmaceuticals in aqueous solutions. We investigated whether coinjection of a minimal amount of PS80 had a modulatory effect on the immunotherapeutic effects of Cry (Cryptomeria)‐consensus peptide, a novel peptide developed for the therapeutic management of Japanese cedar pollinosis, using a Cry j 1‐sensitized mouse model with experimental allergic rhinitis. Subcutaneous challenge with Cry‐consensus peptide plus 50 µg/ml of PS80 did not affect the antigen‐specific proliferation of splenocytes, but decreased the potency of Cry‐consensus peptide to inhibit antigen‐specific interleukin (IL)‐5 production by the cells significantly in comparison with challenge with Cry‐consensus peptide alone. However, there was no significant difference between the effect of Cry‐consensus peptide administration on interferon (IFN)‐γ production in the presence and absence of PS80, indicating that PS80 interfered with the T helper 1 (Th1)‐dominant T helper balance induced by Cry‐consensus peptide challenge. Moreover, the increase in the level of antigen‐specific immunoglobulin G2a (IgG2a) induced by Cry‐consensus peptide challenge was inhibited slightly but unambiguously by PS80 coinjection. These in vitro experiments indicated that PS80 induces Th2‐type differentiation of T helper cells through preferential inhibition of IFN‐γ expression relative to IL‐5 expression in splenocytes in a concentration‐dependent manner. In naïve mice, sensitization by Cry‐consensus peptide with PS80 induced antigen‐specific IL‐5 production more potently than sensitization by Cry‐consensus peptide alone, and when PS80 was added to bone marrow‐derived dendritic cells, the endocytosis of fluorescence‐labelled Cry‐consensus peptide was dramatically inhibited in a concentration‐dependent manner. Therefore, we conclude that PS80 has an immunomodulatory effect on the antigen‐specific response resulting in a shift towards Th2 predominance with respect to the antigen recognition stage. Taken together, our findings suggest that PS80 might decrease the efficacy of Cry‐consensus peptide through modulation of the efficiency of antigen endocytosis and/or of the direction of successive T helper cell differentiation.
Interventions with fathers of young children: systematic literature review
Authors: Magill‐Evans Joyce , Harrison Margaret J. , Rempel Gwen , Slater Linda
Published: May 2006

Aim.  This paper reports a systematic review of the effectiveness of interventions for fathers with infants or toddlers.

Background.  Nurses and other healthcare professionals work closely with families of infants and young children. This contact provides an opportunity to promote positive parent–child interactions and optimal child development. Previous research has demonstrated that interventions with mothers of infants can be effective in promoting sensitive, responsive parent–child interactions and positive child development. Recent research has indicated that fathers also contribute to child development, but little is known about what types of interventions with fathers are effective in promoting sensitive, responsive father–child interactions.

Methods.  Literature from 1983 to 2003 in the Medline, CINAHL, and PsycINFO databases was searched to locate intervention studies published in English that included a control group or used a pretest and post‐test design; measured an aspect of father–child interaction; analysed father outcomes separately from mother outcomes; had a sample greater than one; and included infants or toddlers. Additional studies were located by cross‐checking reference lists.

Results.  Fourteen papers describing 12 interventions met the inclusion criteria. The interventions included infant massage, observation and modelling of behaviour with infant, kangaroo care, participation with child in a preschool programme, discussion groups, and parent training programmes.

Conclusion.  Although the number of intervention studies is limited, there is evidence that, if interventions involve active participation with or observation of the father's own child, the intervention may be effective in enhancing the father's interactions with the child and a positive perception of the child. There is less information on how interventions influence child development. More research is needed to determine the influence of interventions over time, the differential influence on mothers and fathers, and the optimal dose of intervention required.
Does the migration programme constrain dispersal and range sizes of migratory birds?
Authors: Thorup Kasper
Published: May 2006

Aim  It is generally believed that the migration programme constrains the dispersal and hence range sizes of migratory bird species. This conclusion is based on analyses of breeding ranges of migratory versus non‐migratory (resident) terrestrial bird species, and rests on the assumption that there are no ecological or evolutionary constraints on extending the non‐breeding range. To investigate this assumption, the abilities of migrant and resident terrestrial species to colonize new wintering areas were compared.

Location  Three major wintering regions of long‐distance migrants: South America, sub‐Saharan Africa and the Indian Subcontinent.

Methods  It was determined whether the relative numbers of residents and short‐ and long‐distance migrants were the same in those species that have dispersed to a novel wintering region as in the source species pools.

Results  At the species level, long‐distance migratory species are more likely to have non‐breeding ranges that include more than one of the above regions than resident species. This indicates that the dispersal of migratory species is less constrained than that of resident species. The pattern holds irrespective of the inclusion or exclusion of species associated with coastal, freshwater and wetland habitats, and also holds for ecological groups such as aerial feeders. The pattern is most pronounced between the regions separated by the strongest dispersal barriers (South America and sub‐Saharan Africa).

Main conclusions  It is unlikely that the migration programme per se constrains dispersal, but rather that difficulties in establishing new non‐breeding areas prevent range expansions in migrant species.
Comparative phylogeography of woodland reptiles in California: repeated patterns of cladogenesis and population expansion
Authors: FELDMAN CHRIS R. , SPICER GREG S.
Published: May 2006

The ultimate goal of comparative phylogeographical analyses is to infer processes of diversification from contemporary geographical patterns of genetic diversity. When such studies are employed across diverse groups in an array of communities, it may be difficult to discover common evolutionary and ecological processes associated with diversification. In order to identify taxa that have responded in a similar fashion to historical events, we conducted comparative phylogeographical analyses on a phylogenetically and ecologically limited set of taxa. Here, we focus on a group of squamate reptiles (snakes and lizards) that share similar ecological requirements and generally occupy the same communities in the western USA. At a gross level, deep genetic division in Contia tenuis, Diadophis punctatus, Elgaria multicarinata, the Charina bottae complex, and Lampropeltis zonata are often concordant in the Transverse Ranges, the Monterey Bay and Sacramento‐San Joaquin Delta region, and the southern Sierra Nevada in California. Molecular clock estimates suggest that major phyletic breaks within many of these taxa roughly coincide temporally, and may correspond to important geological events. Furthermore, significant congruence between the phylogeographies of E. multicarinata and L. zonata suggests that the succession of vicariance and dispersal events in these species progressed in concert. Such congruence suggests that E. multicarinata and L. zonata have occupied the same communities through time. However, across our entire multi‐taxon data set, the sequence of branching events rarely match between sympatric taxa, indicating the importance of subtle differences in life history features as well as random processes in creating unique genetic patterns. Lastly, coalescent and noncoalescent estimates of population expansion suggest that populations in the more southerly distributed clades of C. tenuis, D. punctatus, E. multicarinata, and L. zonata have been stable, while populations in more northerly clades appear to have recently expanded. This concerted demographic response is consistent with palaeontological data and previous phylogeographical work that suggests that woodland habitat has become more restricted in southern California, but more widespread in the North during Holocene warming. Future phylogeographical work focusing on allied and ecologically associated taxa may add insight into the ecological and evolutionary processes that yield current patterns of genetic diversity.
Gene flow and functional connectivity in the natterjack toad
Authors: STEVENS VIRGINIE M. , VERKENNE CATHERINE , VANDEWOESTIJNE SOFIE , WESSELINGH RENATE A. , BAGUETTE MICHEL
Published: May 2006

Functional connectivity is a key factor for the persistence of many specialist species in fragmented landscapes. However, connectivity estimates have rarely been validated by the observation of dispersal movements. In this study, we estimated functional connectivity of a real landscape by modelling dispersal for the endangered natterjack toad (Bufo calamita) using cost distance. Cost distance allows the evaluation of ‘effective distances’, which are distances corrected for the costs involved in moving between habitat patches in spatially explicit landscapes. We parameterized cost‐distance models using the results of our previous experimental investigation of natterjack's movement behaviour. These model predictions (connectivity estimates from the GIS study) were then confronted to genetic‐based dispersal rates between natterjack populations in the same landscape using Mantel tests. Dispersal rates between the populations were inferred from variation at six microsatellite loci. Based on these results, we conclude that matrix structure has a strong effect on dispersal rates. Moreover, we found that cost distances generated by habitat preferences explained dispersal rates better than did the Euclidian distances, or the connectivity estimate based on patch‐specific resistances (patch viscosity). This study is a clear example of how landscape genetics can validate operational functional connectivity estimates.
High genetic diversity in a rare and endangered sunflower as compared to a common congener
Authors: ELLIS J. R. , PASHLEY C. H. , BURKE* J. M. , McCAULEY D. E.
Published: May 2006

Determining the genetic structure of isolated or fragmented species is of critical importance when planning a suitable conservation strategy. In this study, we use nuclear and chloroplast SSRs (simple sequence repeats) to investigate the population genetics of an extremely rare sunflower,Helianthus verticillatusSmall, which is known from only three locations in North America. We investigated levels of genetic diversity and population structure compared to a more common congener,Helianthus angustifoliusL., using both nuclear and chloroplast SSRs. We also investigated its proposed hybrid origin fromHelianthus grosseserratusMartens andH. angustifolius. Twenty‐two nuclear SSRs originating from the cultivated sunflower (Helianthus annuusL.) expressed sequence tag (EST) database, and known to be transferable toH. verticillatusand its putative parental taxa, were used in this study thereby allowing for statistical control of locus‐specific effects in population genetic analyses. Despite its rarity,H. verticillatuspossessed significantly higher levels of genetic diversity thanH. angustifoliusat nuclear loci and equivalent levels of chloroplast diversity. Significant levels of population subdivision were observed inH. verticillatusbut of a magnitude comparable to that ofH. angustifolius.Inspection of multilocus genotypes also revealed that clonal spread is highly localized. Finally, we conclude thatH. verticillatusis not of hybrid origin as it does not exhibit a mixture of parental alleles at nuclear loci, and it does not share a chloroplast DNA haplotype with either of its putative parents.
Relationships between optically assessed polyphenols and chlorophyll contents, and leaf mass per area ratio in woody plants: a signature of the carbon–nitrogen balance within leaves?
Authors: MEYER S. , CEROVIC Z. G. , GOULAS Y. , MONTPIED P. , DEMOTES‐MAINARD S. , BIDEL L. P. R. , MOYA I. , DREYER E.
Published: May 2006

Chlorophyll (Chl) and epidermal polyphenol (EPhen) contents were estimated in vivo using two optical leaf‐clips, SPAD‐502 and Dualex, respectively. The area‐based measurements were transformed into mass‐based data by taking into account the leaf dry mass per area (LMA). Measurements were performed on forest trees and on saplings grown under controlled conditions. While LMA increased with irradiance along a vertical transect in a beech canopy or in saplings grown under different and increasing irradiance levels, mass‐based EPhen (EPhenm) increased, whereas mass‐based Chl (Chlm) decreased. This was a signature of a gradual switch of investment from protein into polyphenol production. A similar signature was obtained in saplings grown on nitrogen‐deficient soil with respect to fertilized controls. However, nitrogen effects remained moderate compared to irradiance‐induced effects. EPhenm and Chlm both declined with plant ageing‐induced increases in LMA, under all tested growth conditions. This was a signature of an accumulation of dry matter that diluted Chl and EPhen. The described competition between Chl and EPhen in leaves fits well with the predictions of the Protein Competition Model (PCM), that is, that the total leaf mass‐based polyphenols content (Phent) is controlled by the competition between protein and polyphenol biosynthetic pathways and its metabolic regulation.
Temperature dependence of nitrate reductase in the psychrophilic unicellular alga Koliella antarctica and the mesophilic alga Chlorella sorokiniana
Authors: DI MARTINO RIGANO VITTORIA , VONA VINCENZA , LOBOSCO ORNELLA , CARILLO PETRONIA , LUNN JOHN E. , CARFAGNA SIMONA , ESPOSITO SERGIO , CAIAZZO MARIANNA , RIGANO CARMELO
Published: May 2006

Temperature responses of nitrate reductase (NR) were studied in the psychrophilic unicellular alga, Koliella antarctica, and in the mesophilic species, Chlorella sorokiniana. Enzymes from both species were purified to near homogeneity by Blue Sepharose (Pharmacia, Uppsala, Sweden) affinity chromatography and high‐resolution anion‐exchange chromatography (MonoQ; Pharmacia; Uppsala, Sweden). Both enzymes have a subunit molecular mass of 100 kDa, and K. antarctica NR has a native molecular mass of 367 kDa. NR from K. antarctica used both NADPH and NADH, whereas NR from C. sorokiniana used NADH only. Both NRs used reduced methyl viologen (MVH) or benzyl viologen (BVH). In crude extracts, maximal NADH and MVH‐dependent activities of cryophilic NR were found at 15 and 35 °C, respectively, and retained 77 and 62% of maximal activity, respectively, at 10 °C. Maximal NADH and MVH‐dependent activities of mesophilic NR, however, were found at 25 and 45 °C, respectively, with only 33 and 23% of maximal activities being retained at 10 °C. In presence of 2 µm flavin adenine dinucleotide (FAD), activities of cryophilic NADH:NR and mesophilic NADH:NR were stable up to 25 and 35 °C, respectively. Arrhenius plots constructed with cryophilic and mesophilic MVH:NR rate constants, in both presence or absence of FAD, showed break points at 15 and 25 °C, respectively. Essentially, similar results were obtained for purified enzymes and for activities measured in crude extracts. Factors by which the rate increases by raising temperature 10 °C (Q10) and apparent activation energy (Ea) values for NADH and MVH activities measured in enzyme preparations without added FAD differed slightly from those measured with FAD. Overall thermal features of the NADH and MVH activities of the cryophilic NR, including optimal temperatures, heat inactivation (with/without added FAD) and break‐point temperature in Arrhenius plots, are all shifted by about 10 °C towards lower temperatures than those of the mesophilic enzyme. Transfer of electrons from NADH to nitrate occurs via all three redox centres within NR molecule, whereas transfer from MVH requires Mo‐pterin prosthetic group only; therefore, our results strongly suggest that structural modification(s) for cold adaptation affect thermodynamic properties of each of the functional domains within NR holoenzyme in equal measure.
The spatial and temporal variability of sand erosion across a stabilizing coastal dune field
Authors: LEVIN NOAM , KIDRON GIORA J. , BEN‐DOR EYAL
Published: May 2006

This study aimed at quantifying the temporal and spatial variability in sand erosion and deposition over a coastal dune field in Israel. These were measured monthly over 2 years using 315 erosion pins over four transects that were placed perpendicular to the coastline. Vegetation cover was estimated based on aerial photographs and Landsat satellite images, whereas the relative height was based on a digital elevation model. These variables were calculated for the area upwind (south west) of the erosion pins, at various lengths, ranging from 15 to 400 m. Nine geomorphologic units were defined, five related to active units, and four to stabilized units. In active units at least 65% of the temporal variance in the annual absolute changes in sand level was explained by the index of Resultant Drift Potential, with most of the sand movement occurring during winter storms. Local rainfall had no apparent impact on sand mobility, due to the low coincidence of sand carrying winds and rainfall in Israel during the passage of frontal cyclones. As for the spatial variables, only a weak correlation was found between sand mobility with the distance from the coastline (R2 = 18%). Rather, sand erosion and deposition were influenced by vegetation cover and the relative height of an area of 100–200 m upwind. The values of Soil Adjusted Vegetation Index were significantly negatively correlated with annual absolute changes (R2 = 40%), whereas the relative height was significantly positively correlated (R2 = 36%). Applying a multiple regression model, 68% of the spatial variability in sand mobility was explained. The resulting map of sand activity clearly shows that at this stage of the stabilization process, most of the dunes are now disconnected, and movement of sand grains from the beach or between the dunes, is very limited. These methods can be applied into spatial and temporal models of sand mobility, thus assessing the impact of different management practices on coastal dunes.
Interplay between shoreline migration paths, architecture and pinchout distance for siliciclastic shoreline tongues: evidence from the rock record
Authors: LØSETH TORE M. , STEEL RON J. , CRABAUGH JEFF P. , SCHELLPEPER MAIJA
Published: May 2006

Facies, geometry and key internal stratigraphic surfaces from eight Cretaceous and Eocene clastic shoreline tongues have been documented. The regressive parts of all the studied tongues represent storm‐wave influenced strandplains, deltas or fan‐deltas, and the regressive shoreline trajectories varied from descending to ascending. The transgressive parts of the tongues are dominated by either estuarine or coastal‐plain deposits. The distance from the coeval, up‐dip non‐marine deposits to the basinward pinchout of amalgamated shoreface sandstones, measured along depositional dip, is here termed the sand pinchout distance. The study shows that the angle of regressive‐to‐transgressive turnaround (defined by the angle between the regressive and subsequent transgressive shoreline trajectories) and the process regime during turnaround largely control the sand‐pinchout distance. The amount of transgressive erosion can also partly control the pinchout distance, but this parameter was comparable for the different examples presented here. If the type of depositional system at turnaround and the depth of transgressive erosion are constant, small angles of turnaround are associated with large pinchout distances, whereas larger angles of turnaround result in smaller pinchout distances. The model developed allows sand‐pinchout distance to be predicted, using data for the landward parts of shoreline tongues. The dataset also shows that steeply rising (aggrading) shoreline trajectories tend to produce more heterolithic sandstone tongues than those formed by lower‐angle trajectories.
A novel mutation in the EIF2AK3 gene with variable expressivity in two patients with Wolcott–Rallison syndrome
Authors: Durocher F , Faure R , Labrie Y , Pelletier L , Bouchard I , Laframboise R
Published: May 2006

Mutations in the EIF2AK3 gene have been identified in patients with Wolcott–Rallison syndrome – a rare autosomal recessive disorder associated with permanent neonatal insulin‐dependent diabetes. Despite the fact that different mutations have been observed in every single unrelated case reported so far, most patients presented with similar characteristics, such as osteopenia, epiphyseal dysplasia as well as hepatic and/or renal dysfunction. The EIF2AK3 gene was analyzed using a PCR‐based sequencing approach in two Wolcott–Rallison patients and their parents. We report two cases from different families carrying the same and novel truncating nonsense mutation in the EIF2AK3 gene that encodes the pancreatic eukaryotic initiation factor 2α kinase 3. This mutation clearly displays different clinical characteristics in the two patients we examined. Remarkably, the onset of diabetes was different for the two patients, and there was also heterogeneity in other clinical manifestations. These cases illustrate the important role of alternative pathways that could, to some extent, take over or supplement a defective metabolic pathway. This supports the idea that there is no simple relationship among clinical manifestations and EIF2AK3 mutations.
Experience with an organ procurement organization‐based non‐directed living kidney donation programme
Authors: Mark Paula J. , Baker Kristie , Aguayo Cecile , Sorensen John B.
Published: May 2006

Abstract:  The organ procurement organization (OPO)‐based non‐directed living kidney donation programme was developed to decrease wait times for kidney transplants, and to meet the community's desire for altruistic living donation. Community awareness was encouraged through information about non‐directed living kidney donation on the state donor registry Web site, and through the media. The OPO received all inquiries and responded with phone calls, e‐mails, printed information, medical/social history questionnaires, interviews, and referrals to the transplant centres. Kidneys were allocated according to the United Network for Organ Sharing (UNOS) wait list for the evaluating transplant centre. Between March 2002 and 23 September 2005, there were 608 inquiries to the OPO about non‐directed living kidney donation. In 41 months, 20 transplants occurred with kidneys from non‐directed donors. The donor registry and OPO‐sponsored publicity led to 578 of the 608 inquiries and 15 of the 20 transplants. OPO screening saved transplant centre resources by ruling out 523 inquiries, referring 76 to transplant centres for complete evaluations. Optional donor/recipient meetings appeared to be beneficial to those participating. OPO‐based non‐directed living donor programmes can be effective and efficient. Standardization of evaluation, allocation, and follow‐up will allow for better data collection and more widespread implementation.
Cost‐effectiveness of sirolimus therapy with early cyclosporin withdrawal vs. long‐term cyclosporin therapy in Australia
Authors: Gordois Adam , Nobes Michael , Toohey Michaela , Russ Graeme
Published: May 2006

Abstract:  Cyclosporin (CsA) is Australia's most widely used immunosuppressant following renal transplantation. Randomized clinical trials demonstrate that sirolimus use for immunosuppression is associated with significantly lower incidence rates of nephrotoxicity and chronic graft rejection, and lower serum creatinine levels, suggesting long‐term benefits if used as a replacement therapy for CsA. The cost‐effectiveness of replacing CsA with sirolimus after 2–4 months (as approved by Australian regulatory authorities) was assessed relative to continued CsA plus low‐dose sirolimus. A Markov model simulated outcomes over a patient's lifetime from initial transplant. Costs, measured in Australian dollars from the perspective of the Australian healthcare system, included immunosuppressants, dialysis, and inpatient and outpatient treatment. In a cohort with a mean age of 45 yr, the mean lifetime cost per patient is $39 052 greater with the study therapy. However, an average of 272 chronic graft rejections and 91 regrafts are prevented per 1000 patients. The mean predicted survival benefit is 2.086 life‐years, or 0.938 quality‐adjusted life‐years (QALYs) when utility weights and discounting are incorporated. The incremental cost per QALY gained with the study therapy was $41 613. Cost‐effectiveness was most sensitive to model duration and dialysis cost. Sirolimus is a cost‐effective alternative to CsA for the long‐term treatment of patients undergoing renal transplantation.
The efficacy of liver transplantation in malignant liver tumors associated with tyrosinemia: Clinical and laboratory findings of five cases
Authors: Büyükpamukçu Münevver , Varan Ali , Haberal Mehmet , Büyükpamukçu Nebil , Köksal Yavuz , Coşkun Turgay , Yüce Aysel , Kale Gülsev , Akyüz Canan , Kutluk Tezer
Published: May 2006

Abstract:  To evaluate clinical and laboratory findings of these patients and the efficacy of liver transplantation in children with hepatocellular carcinoma (HCC) and hepatoblastoma (HB) associated with tyrosinemia. Among 113 children with liver tumors diagnosed between 1972 and 2004 five patients had HCC or HB associated with tyrosinemia. The age at diagnosis of the HCC or HB ranged from 9.5 to 17 yr and male:female ratio was 1:4. During regular clinic visits for tyrosinemia, elevated alpha‐fetoprotein (AFP) was detected in all patients. AFP levels ranged between 13.7 and 29 340 IU/mL. Radiological studies including ultrasound, computed tomography and magnetic resonance imaging showed heterogeneous parenchyma and nodules in the liver. The patients did not have any metastatic disease. The time from diagnosis of tyrosinemia to HCC or HB ranged from 9.25 to 15.25 yr. Histopathologically, four patients have been diagnosed as HCC and one patient had HB. All patients were given chemotherapy including cisplatin and adriamycin. In three patients, living‐related liver transplantation was performed. They had no treatment after transplantation. All of them are disease free. One patient was treated with chemotherapy and right hepatectomy. She had no suitable donor for living‐related liver transplantation. Three months after completing chemotherapy, she had recurrent tumor in the left lobe of the liver and she died with progressive disease. The last patient whose parents were not suitable as donors for living‐related liver transplantation is waiting for a deceased donor graft. All patients had limited disease to liver due to close clinical and radiological follow up for tyrosinemia. In these patients liver transplantation is curative both for liver tumor and tyrosinemia.
Living‐related liver transplantation with removal of inferior vena cava for unresectable hepatoblastoma
Authors: Hasegawa Toshimichi , Kimura Takuya , Ihara Yoshiyuki , Tazuke Yuko , Yoneda Akihiro , Kusafuka Takeshi , Fukuzawa Masahiro , Okuyama Hiroomi , Inoue Masami
Published: May 2006

Abstract:  We report a case of a two‐yr‐old boy with hepatoblastoma resectable only by total hepatectomy including the vena cava. Successful LTx was performed with a living donor segment without vena cava reconstruction. The tumor was located in the bilateral lobe, surrounding the IVC. In spite of the high‐dose chemotherapy, the tumor did not become resectable. LTx was performed using left lateral segment after removal of the IVC combined with total hepatectomy. Because the collaterals were well developed, the patient tolerated the procedure well. The serum AFP level decreased from 186 699 to 8 ng/mL in 11 months after LTx without local recurrence or distant metastasis.
Long‐term protection against hepatitis B in pediatric liver recipients can be achieved effectively with vaccination after transplantation
Authors: Kwon Choon Hyuck David , Suh Kyung‐Suk , Yi Nam‐Joon , Chang Seong‐Hwan , Cho Yong Beom , Cho Jai‐Young , Lee Hoan Jong , Seo Jeong Kee , Lee Kuhn Uk
Published: May 2006

Abstract:  Liver recipients who have antibodies to hepatitis B core antigen (anti‐HBc) or received an anti‐HBc positive liver graft are at risk of acquiring de novo hepatitis B infection so a life long prophylaxis is required. A post‐transplant vaccination against hepatitis B virus (HBV) can offer a better alternative than either hepatitis B hyperimmune globulin (HBIG) or lamivudine. This study investigated the course of anti‐HBs titer after vaccination and analyzed the factors that influence the response. Between October 1999 and February 2003, 37 pediatric patients were given a post‐transplant vaccination when an anti‐HBc positive graft was used, the recipient was anti‐HBc positive, or when anti‐HBs titer was below 20 IU/L irrespective of the serological status. Thirty‐three patients responded to the vaccine and did not require further HBIG injections at a mean follow up of 33.6 months. Fifteen patients were good responder and only needed a single set of vaccines, and 18 were poor responder needing additional boosters. Two patients developed de novo hepatitis B infection and two required additional HBIG injections. Preoperative severity of liver disease, serological status of HBV of recipient or donor, use of HBIG or pulse steroid therapy, type of vaccines, and dose or time interval between doses had no influence on response rate. Recipients with a high preoperative anti‐HB titer, small graft–recipient weight ratio (GRWR), greater catch up growth, heavier body weight, lower tacrolimus level at the time of vaccination, and longer time interval between transplant or steroid medication and vaccination yielded good response. If well tailored, post‐transplant vaccination can be effective and offer patients prophylaxis against de novo hepatitis B infection for a prolonged period of time.
Theoretical influence of female mating status and remating propensity on male sperm allocation patterns
Authors: Engqvist L. , Reinhold K.
Published: May 2006

Theoretical models predict that males should allocate more sperm in matings where the immediate risk of sperm competition is high. It has therefore often been argued that males should invest less sperm in matings with virgin females compared with matings with already mated females. However, with relatively polyandrous females, high sperm competition risk will covary with high sperm competition intensity leading to more unpredictable conditions, as high competition intensity should favour smaller ejaculates. With the use of a genetic algorithm, we found that males should allocate more sperm in matings with virgin females when female mating frequency is relatively high, whereas low remating rates will select for higher effort in matings with nonvirgin females. At higher remating rates, first male sperm precedence favours larger ejaculates in matings with virgin females and second male precedence favours the reverse. These results shed some light on several findings that have been difficult to explain adaptively by the hitherto developed theory on sperm allocation.