bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heat shock protein 90 inhibitor 17‐allylamino‐17‐demethoxygeldanamycin potentiates the radiation response of tumor cells grown as monolayer cultures and spheroids by inducing apoptosis
Authors: Machida Hikaru , Nakajima Syuichi , Shikano Naoto , Nishio Junko , Okada Shinobu , Asayama Munehiko , Shirai Makoto , Kubota Nobuo 
Published: December 2005

Activation of the PI3K‐Akt pathway is known to induce tumor radioresistance. In the current study, we examined the ability of 17AAG, which decreases the levels of Hsp90 client proteins including components of the PI3K‐Akt pathway, to sensitize radioresistant human squamous cell carcinoma cells to X‐irradiation. Human squamous cell carcinoma cell lines (SQ20B, SCC61 and SCC13) were incubated for 16 h at 37°C in medium containing 17AAG. Radiation sensitivity was determined by clonogenic assays, and protein levels were examined by western blotting. Apoptosis was determined in monolayer cells by AO/EB double staining and in spheroids using the TdT‐mediated dUTP nick end labeling assay. 17AAG (0.2 µM) enhanced the radiosensitivity more effectively in radioresistant SQ20B and SCC13 cells than in radiosensitive SCC61 cells. However, in all three cell lines, 17AAG increased radiation‐induced apoptosis by reducing the expression of EGFR and ErbB‐2 and inhibiting the phosphorylation of Akt. Furthermore, 17AAG (1 µM) sensitized SQ20B spheroids to radiation, and inhibition of Akt activation by 17AAG increased radiation‐induced apoptosis in spheroids. The findings suggest that 17AAG effectively sensitizes radioresistant cells to radiation by inhibiting the PI3K‐Akt pathway. Targeting the PI3K‐Akt pathway with 17AAG could be a useful strategy for radiosensitization of carcinomas. (Cancer Sci 2005; 96: 911–917)
Empirical antifungal therapy in patients with neutropenia and persistent or recurrent fever of unknown origin
Authors: Martino Rodrigo , Viscoli Claudio 
Published: December 2005

SummaryPersistent or recurrent fever of unexplained origin (PFUO) in neutropenic patients receiving antibiotic therapy is commonly treated with empirical antifungal therapy (EAFT). EAFT was established as an adequate management of PFUO around 20 years ago with conventional amphotericin B deoxycholate (c‐AmB), despite its high rate of infusional and systemic toxicities. In recent years, EAFT trials for PFUO have used less toxic agents, such as the lipid formulations of AmB, the new azoles, and the echinocandin, caspofungin. In clinical trials, the lipid formulations of AmB [especially liposomal AmB (L‐AmB)] provided similar efficacy with lower toxicity but at a much higher cost. Although rarely used in clinical practice, fluconazole is equivalent to c‐AmB, provided patients at high risk of Aspergillus infections are excluded. Intravenous itraconazole was shown to be equivalent to c‐AmB, with a lower toxicity. Voriconazole did not meet non‐inferiority criteria when compared with L‐AmB. Caspofungin was shown to be non‐inferior to L‐AmB and more effective in treating baseline invasive fungal infections. To date, alternatives to AmB have shown less toxicity, but improved efficacy is less clear. This is probably because of the weakness of the indication and to the consequent difficulty in establishing objective and reproducible endpoints for comparisons. The new challenge for physicians in this field is probably presumptive antifungal therapy, an approach based on patient risk‐group stratification for developing invasive candidiasis or aspergillosis and/or the use of new diagnostic techniques to identify patients at a very early stage of infection.
Flooding, soil seed bank dynamics and vegetation resilience of a hydrologically variable desert floodplain
Authors: CAPON SAMANTHA J. , BROCK MARGARET A. 
Published: December 2005

Summary1. This paper explores soil seed bank composition and its contribution to the vegetation dynamics of a hydrologically variable desert floodplain in central Australia: the Cooper Creek floodplain. We investigated patterns in soil seed bank composition both temporally, in response to flooding (and drying), and spatially, with relation to flood frequency. Correlations between extant vegetation and soil seed bank composition are explored with respect to flooding.2. A large and diverse germinable soil seed bank was detected comprising predominantly annual monocot and annual forb species. Soil seed bank composition did not change significantly in response to a major flood event but some spatial patterns were detected along a broad flood frequency gradient. Soil seed bank samples from frequently flooded sites had higher total germinable seed abundance and a greater abundance of annual monocots than less frequently flooded sites. In contrast, germinable seeds of perennial species belonging to the Poaceae family were most abundant in soil seed bank samples from rarely flooded sites.3. Similarity between the composition of the soil seed bank and extant vegetation increased following flooding and was greatest in more frequently flooded areas of the floodplain, reflecting the establishment of annual species. The results indicate that persistent soil seed banks enable vegetation in this arid floodplain to respond to unpredictable patterns of flooding and drying.
Dispersal of plant fragments in small streams
Authors: RIIS TENNA , SAND‐JENSEN KAJ 
Published: December 2005

Summary1. Streams are subject to frequent natural and anthropogenic disturbances that cause sediment erosion and loss of submerged vegetation. This loss makes downstream transport and retention of vegetative propagules on the streambed very important for re‐establishing vegetation cover. We measured dispersal and retention of macrophyte stem fragments (15–20 cm long) along 300 m long reaches of four small to medium sized Danish lowland streams.2. The number of drifting stem fragments declined exponentially with distance below the point of release. This finding makes the retention coefficient (k, m−1) in the exponential equation a suitable measure for comparisons among different macrophyte species, and between stream reaches of different hydrology and vegetation cover.3. Buoyancy of macrophyte tissue influenced retention.Elodea canadensisstems drifted below the water surface, and were more inclined to be retained in deeper water associated with submerged plants and obstacles in the streambed.Ranunculus peltatusstems were more buoyant, drifted at the water surface, and were more inclined to be trapped in shallow water and in riparian vegetation.4. The retention coefficient of drifting stems increased with the relative contact between the flowing water and streambed, bank and vegetation. Thus, the retention coefficients were highest (0.02–0.12 m−1) in shallow reaches with a narrow, vegetation‐free flow channel. Here there were no significant differences betweenE. canadensisandR. peltatus. Retention coefficients were lowest (0.0005–0.0135 m−1) in deeper reaches with wider vegetation‐free flow channels. Retention ofE. canadensiswas up to 16 times more likely than retention ofR. peltatus.5. Overall, the longitudinal position in the stream system of source populations of species capable of producing numerous stems, the species‐specific retention coefficients of stems, and the retention capacity of stream reaches should be important for species distribution in perturbed stream systems. Retention of stems is probably constrained in headwaters by the small downstream flux of stem fragments because of the restricted source area, and constrained in downstream reaches by small retention coefficients. Macrophyte retention may, consequently, peak in medium‐sized streams.
Accounting for velocity anisotropy in seismic traveltime tomography: a case study from the investigation of the foundations of a Byzantine monumental building
Authors: Polymenakos L. , Tweeton D. , Papamarinopoulos S. 
Published: December 2005

ABSTRACTWe estimate velocity anisotropy factors from seismic traveltime tomographic data and apply a correction for anisotropy in the inversion procedure to test possible improvements on the traveltime fit and the quality of the resulting tomographic images. We applied the anisotropy correction on a traveltime data set obtained from the investigation of the foundation structure of a monumental building: a Byzantine church from the 11th century AD, in Athens, Greece.Vertical transverse isotropy is represented by one axis of symmetry and one anisotropy magnitude for the entire tomographic inversion grid. We choose the vertical direction for the symmetry axis by analysing the available data set and taking into account information on the character of the foundations of the church from the literature and past excavations. The anisotropy magnitude is determined by testing a series of values of anisotropy and examining their effect on the tomographic inversion results. The best traveltime fit and image quality are obtained with an anisotropy value (Vmax/Vmin) of 1.6, restricted to the high velocity structures in the subsurface. We believe that this anisotropy value, which is significantly higher than the usual values reported for near‐surface geological material, is related to the fabric of the church foundations, due to the shape of the individual stone blocks and the layout of the stonework.Inversion results obtained with the correction for anisotropy indicate that both the traveltime fit and the image quality are improved, providing an enhanced reconstruction of the velocity field, especially for the high‐velocity features. Based on this enhanced and more reliable reconstruction of velocity distribution, an improved image of the subsurface material character was made possible. In particular, the pattern and state of the church foundations and possible weak ground material areas were revealed more clearly. This improved subsurface knowledge may assist in a better design of restoration measures for monumental buildings such as Byzantine churches.
Seismic monitoring of pressure depletion evaluated for a United Kingdom continental‐shelf gas reservoir
Authors: MacBeth Colin , Stammeijer Jan , Omerod Mark 
Published: December 2005

ABSTRACTThe possibility of using 4D seismic data for monitoring pressure depletion in the low‐porosity, tight gas‐bearing Rotliegende sandstones of the UK Southern Gas Basin is investigated. The focus here is on whether fractures in the upper part of the reservoir, known to enhance productivity, can also enhance the time‐lapse seismic response. The study uses laboratory data to evaluate core‐plug stress sensitivity, published data for the stress behaviour of the fractures, followed by petro‐elastic and 4D seismic modelling of both the fractured and unfractured formation. The magnitude of the resultant 4D signatures suggests that production‐induced changes in the unfractured sands are unlikely to be observed except perhaps with highly repeatable time‐lapse surveys. On the other hand, the presence of fractures could render production effects visible in dedicated 4D acquisition or prestack parallel processed data. If present however, the signature will be sporadic, as fractures in the area are known to exist in clusters. The 4D signature may be enhanced further by certain classes of vertical geological variability and also areas of high reservoir pressure. The strongest evidence of depletion is expected to be time‐shifts seen at the base of the Rotliegende reservoir.
Mature monocyte‐derived dendritic cells respond more strongly to CCL19 than to CXCL12: consequences for directional migration
Authors: Humrich Jens Y. , Humrich Jan H. , Averbeck Marco , Thumann Peter , Termeer Christian , Kämpgen Eckhart , Schuler Gerold , Jenne Lars 
Published: December 2005

SummaryThe chemokine receptor CCR7 is crucial for migration of mature dendritic cells (DC) directed toward secondary lymphoid organs; however, there is little knowledge about the function of the homeostatic chemokine receptor CXCR4 in DC and its contribution to directional migration of DC during inflammation. By comparing the impact of chemokine receptor engagement on mature DC we found that the CCR7 ligand CCL19 holds a stronger chemotactic potency than the CXCR4 ligand CXCL12. Moreover, CCL19 elicited rapid, steep and long‐lasting mobilization of intracellular calcium in individual cells and induced intense phosphorylation of extracellular signal‐regulated kinase 1/2 and protein kinase B, while the intracellular signals elicited by CXCL12 were in part distinct and significantly weaker. Analysis of chemokine receptor expression revealed that although CCR7 and CXCR4 were expressed by a similar percentage of DC, the mean fluorescence intensity of CCR7 was up to six times higher, suggesting a higher receptor density. Based on these correlations we propose that the type of chemokine signal in conjunction with the expression and functional activity of the respective chemokine receptor is also determining the migration rate and potency of a chemotactic response in mature DC. In conclusion, our data support the fundamental role of CCR7 for rapidly guiding DC toward secondary lymphoid organs at an extra‐ and intracellular molecular level and on the contrary render CXCR4 a weaker contributor to directional migration of DC during inflammation.
Differential modulatory effects of Annexin 1 on nitric oxide synthase induction by lipopolysaccharide in macrophages
Authors: Smyth Tomoko , Harris Hayley J. , Brown Andrew , Tötemeyer Sabine , Farnfield Belinda A. , Maskell Duncan J. , Matsumoto Makoto , Plevin Robin , Alldridge Louise C. , Bryant Clare E. 
Published: December 2005

SummaryAnnexin‐1 (ANXA1) is a glucocorticoid‐regulated protein that modulates the effects of bacterial lipopolysaccharide (LPS) on macrophages. Exogenous administration of peptides derived from the N‐terminus of ANXA1 reduces LPS‐stimulated inducible nitric oxide synthase (iNOS) expression, but the effects of altering the endogenous expression of this protein are unclear. We transfected RAW264.7 murine macrophage‐like cell lines to over‐express constitutively ANXA1 and investigated whether this protein modulates the induction of iNOS, cyclooxygenase‐2 (COX‐2) and tumour necrosis factor‐α (TNF‐α) in response to LPS. In contrast to exogenous administration of N‐terminal peptides, endogenous over‐expression of ANXA1 results in up‐regulation of LPS‐induced iNOS protein expression and activity. However, levels of iNOS mRNA are unchanged. ANXA1 has no effect on COX‐2 or TNF‐α production in response to LPS. In experiments to investigate the mechanisms underlying these phenomena we observed that activation of signalling proteins classically associated with iNOS transcription was unaffected. Over‐expression of ANXA1 constitutively activates extracellular signal regulated kinase (ERK)‐1 and ERK‐2, components of a signalling pathway not previously recognized as regulating LPS‐induced iNOS expression. Inhibition of ERK activity, by the inhibitor U0126, reduced LPS‐induced iNOS expression in our cell lines. Over‐expression of ANXA1 also modified LPS‐induced phosphorylation of the ERK‐regulated translational regulation factor eukaryotic initiation factor 4E. Our data suggest that ANXA1 may modify iNOS levels by post‐transcriptional mechanisms. Thus differential effects on iNOS expression in macrophages are seen when comparing acute administration of ANXA1 peptides versus the chronic endogenous over‐expression of ANXA1.
Cytotoxic T‐lymphocyte antigen‐4 inhibits GATA‐3 but not T‐bet mRNA expression during T helper cell differentiation
Authors: Nasta Francesca , Ubaldi Vanessa , Pace Luigia , Doria Gino , Pioli Claudio 
Published: December 2005

SummaryNaive CD4+ T‐cell differentiation to T helper 1 (Th1) and Th2 cells is dependent on T‐bet and GATA‐3 factors, respectively. T‐bet and GATA‐3, indeed, through chromatin remodelling allow transcriptional activation of Ifnγ and Th2 cytokine (Il4, Il5, Il13) genes, respectively. We investigated the effects of the negative costimulatory receptor cytotoxic T‐lymphocyte antigen‐4 (CTLA‐4) on GATA‐3 and T‐bet mRNA expression and Th cell differentiation in mouse naive CD4+ T cells. Our results show that CTLA‐4 inhibits GATA‐3 mRNA expression and Th2 cell differentiation. At variance, CTLA‐4 does not affect T‐bet mRNA expression and Th1 cell differentiation. GATA‐3 mRNA expression is inhibited when CD4+ cells are stimulated under both neutral (i.e. absence of cytokines) and Th2‐polarizing (i.e. presence of interleukin (IL)‐4) conditions, the effect being larger under the latter condition. Hence CTLA‐4 might affect the IL‐4/signal transducer and activator of transcription‐6 (STAT6) pathway leading to GATA‐3 mRNA up‐regulation. We found, indeed, that CTLA‐4 engagement inhibits STAT6 activation leaving unaffected the STAT6 protein level. Moreover, CTLA‐4 engagement drastically inhibits IL‐4Rα mRNA and protein up‐regulation under Th2‐polarizing conditions. Thus, CTLA‐4 exerts a tight control on Th2 cell differentiation by negatively regulating both the CD3/CD28 and the IL‐4/STAT6 pathways.
Levels and chemical speciation of arsenic in polychaetes: a review
Authors: Fattorini Daniele , Notti Alessandra , Halt Magdalena N. , Gambi Maria Cristina , Regoli Francesco 
Published: December 2005

AbstractRelatively few studies have characterized basal content and variability of arsenic in polychaetes, despite the potential importance of this element as a pollutant of marine environments. Even less have investigated the chemical speciation of arsenic, occurring as inorganic and organic forms, which reflect a different biological reactivity of the element. In the present paper we integrate existing literature with new data in order to summarize the status quo on arsenic bioaccumulation in polychaetes. We consider species with different trophic habits, phylogenetic relationships, geographic distribution and ecology. Reported data indicate a high variability in arsenic concentration with levels ranging from <1 μg·g−1 to more than 2500 μg·g−1 in different species; some additional species analyzed in this work confirm species‐specific characteristics which are not easily explained by biological or ecological factors. The profile of arsenic compounds in polychaetes is different to that of most aquatic organisms. Typically this element occurs in non‐toxic organic forms, however several polychaete species have been shown to accumulate relatively toxic molecules and subsequently biotransform them by processes such as methylation. Conclusions from the literature review reveal a complex array of arsenic actions in the environment and suggest a biological role of this element in the life history of some polychaete species.
Stripping torque as a predictor of successful internal fracture fixation
Authors: Edwards Thomas R. , Tevelen Greg , English Hugh , Crawford Ross 
Published: December 2005

Background:  Internal fixation of fractures using plates and screws is a common method of treatment. Occasionally the internal fixation fails prior to fracture healing. This often requires revision surgery. Determining the force that internal fixation needs to withstand postoperatively would enable this force to be applied intraoperatively as a test to predict successful fixation. The purpose of the present paper was to determine the minimum stripping torque needed to predict successful internal fixation strength.Methods:  The pull‐out strength and stripping torque relationships of 4.5‐mm cortical bone screws in Sawbones polyurethane foam were determined. Screw forces were directly measured using an LCM load cell washer on a model intertrochanteric neck of femur fracture fixed with 135° 4‐hole pin and plate loaded to single leg stance conditions. Additionally a 135° 4‐hole pin and plate was mounted on foam blocks and loaded until failure of the shaft screws from the foam occurred. Predicted stripping torque/yield load was determined.Results:  Pull‐out strength and stripping torque of 4.5‐mm cortical bone screws in polyurethane foam have a high degree of linear correlation R2 = 0.95. Direct measurement of shaft screw forces at single leg stance conditions were 585−686 N. This correlated with a stripping torque of 0.9 Nm. Load to yield testing at single leg stance conditions corresponded to a stripping torque of 1.8 Nm.Conclusion:  Withstanding 0.9−1.8 Nm of torque during insertion of the femoral shaft screws of a 135° 4‐hole pin and plate predicts that the construct will successfully withstand single leg stance.
Fournier's gangrene: a retrospective clinical study on forty‐one patients
Authors: Ayan Fadil , Sunamak Oguzhan , Paksoy Sabri M. , Polat Semra S. , As Abdullah , Sakoglu Nevin , Cetinkale Oguz , Sirin Feridun 
Published: December 2005

Background:  Fournier's gangrene, first described by Dr Jean Alfred Fournier in 1883, still has a high mortality rate. The prognosis and outcome of such patients were analysed.Methods:  Forty‐one patients with Fournier's gangrene were reviewed on the parameters of age, sex, aetiological agents, predisposing factors, treatment modalities and outcomes.Results:  Although early intervention and careful treatment was carried out, nine of 41 patients (21.9%) died as a result of complications of septicemia. Among the treatment modalities, there were extensive debridement, drainage, excisions of the skin and fascia, colostomy procedure, extensive antibiotic treatment and hyperbaric oxygen therapy. Although a combination of different treatment modalities were used, the mortality rate was 21.9%.Conclusions:  Fournier's gangrene is still a severe disease. Today, hyperbaric oxygen treatment is very effective in the treatment of this disease.
Unsaturated phosphatidylcholine and its application in surgical adhesion
Authors: Chen Yi , Hills Brian A. , Hills Yvette C. 
Published: December 2005

Background:  It has been confirmed that surface‐active phospholipid (SAPL), or surfactant, lines the surface of peritoneum and serves as a release and lubricating agent. The most important component in SAPL is phosphatidylcholine. A previous animal study showed that a saturated phosphatidylcholine, dipalmitoyl‐phosphatidylcholine, reduced the formation of surgical adhesion. Latest studies have indicated that the dominant SAPL species at some sites outside the lung are not saturated phosphatidylcholine but, rather, are unsaturated phosphatidylcholineMethods:  High performance liquid chromatography was used to analyse the phosphatidylcholine profile of dialysate samples obtained from peritoneal dialysis patients. Friction tests were performed on dipalmitoyl‐phosphatidylcholine and selected unsaturated phosphatidylcholine.Results:  It was discovered that unsaturated phosphatidylcholine was the dominant SAPL species inside the peritoneal cavity. They are palmitoyl‐linoleoyl‐phosphatidylcholine, palmitoyl‐oleoylphosphatidylcholine and stearoylarachidonoylphosphatidylcholine. Most interestingly, there was no dipalmitoyl‐phosphatidylcholine detected from these dialysate samples. The coefficients of static and dynamic friction from palmitoyllinoleoyl‐phosphatidylcholine and palmitoyloleoyl‐phosphatidylcholine were measured and found to be lower than that of dipalmitoyl‐phosphatidylcholine.Conclusion:  The results from the current study reveal that unsaturated phosphatidylcholine is the endogenous species inside the peritoneal cavity. This discovery offers further evidence that the dominant SAPL species at non‐lung sites are unsaturated phosphatidylcholine, not saturated phosphatidylcholine, strongly indicating the difference between phosphatidylcholine species distribution at lung and non‐lung sites. Unsaturated phosphatidylcholine has better anti‐friction and lubrication properties than dipalmitoyl‐phosphatidylcholine. Unsaturated phosphatidylcholine‐based SAPL pharmaceutical products should be developed and evaluated.