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High-resolution monitoring of rivers becomes important because more frequent and severe flooding and drought events are expected in the future, caused by climate change. Some key hydrometric variables (water surface elevation, bathymetry, and water surface velocity) can be acquired at high spatial resolution and in a contactless and noninvasive way using Unoccupied Aerial Systems (UAS). This paper presents a large publicly available UAS hydrometric dataset surveyed within a 10 km stretch of Rönne Å in Sweden from 28 August to 1 September 2023. The data were acquired using UAS radar altimetry for water surface elevation mapping, UAS water penetrating radar and UAS sonar for bathymetric mapping, and UAS Doppler radar for surface velocity monitoring. All data are divided into three processing levels: the raw data (Level 1), processed point data (Level 2), and point data referenced to a reference river centerline/reference cross section line (Level 3). In-situ ground truth and legacy UAS hydrometry payload data are included for comparison and validation. Good consistency indicates that the new UAS hydrometry payloads provide satisfactory datasets. [ABSTRACT FROM AUTHOR]

The onset of resistance to artemisinin for malaria treatment has stimulated the quest for novel antimalarial drugs. Herein, the gold(III) coordination complexes Aubipy [Au(bipy)Cl]+ (bipy = 2,2′-bipyridine), Auphen [Au(phen)Cl]+ (phen = phenanthroline), Auterpy [Au(terpy)Cl]2+ (terpy = 2,2′;6′,2″-terpyridine), and corresponding hydrolyzed species, have been investigated as inhibitors of the Plasmodium falciparum aquaglyceroporin (PfAQP) protein by computational methods. Through an in-silico approach using an Umbrella Sampling protocol to sample how Aubipy, Auphen, and Auterpy permeate through the PfAQP, their permeability coefficients were estimated using the Inhomogeneous Solubility Diffusion (ISD) model with promising results. The efficacy of the gold complexes was then probed by an in vitro assay testing the growth inhibition in chloroquine sensitive and resistant P. falciparum strains. In accordance with the computational data, Auterpy achieved the highest efficiency with an IC50 in the nanomolar range (590 nM) on resistant strain cultures, additionally revealing a good selectivity as compared to its activity against the human aquaglyceroporin 3. [ABSTRACT FROM AUTHOR]

Intratumoral cellular heterogeneity necessitates multi-targeting therapies for improved clinical benefits in advanced malignancies. However, systematic identification of patient-specific treatments that selectively co-inhibit cancerous cell populations poses a combinatorial challenge, since the number of possible drug-dose combinations vastly exceeds what could be tested in patient cells. Here, we describe a machine learning approach, scTherapy, which leverages single-cell transcriptomic profiles to prioritize multi-targeting treatment options for individual patients with hematological cancers or solid tumors. Patient-specific treatments reveal a wide spectrum of co-inhibitors of multiple biological pathways predicted for primary cells from heterogenous cohorts of patients with acute myeloid leukemia and high-grade serous ovarian carcinoma, each with unique resistance patterns and synergy mechanisms. Experimental validations confirm that 96% of the multi-targeting treatments exhibit selective efficacy or synergy, and 83% demonstrate low toxicity to normal cells, highlighting their potential for therapeutic efficacy and safety. In a pan-cancer analysis across five cancer types, 25% of the predicted treatments are shared among the patients of the same tumor type, while 19% of the treatments are patient-specific. Our approach provides a widely-applicable strategy to identify personalized treatment regimens that selectively co-inhibit malignant cells and avoid inhibition of non-cancerous cells, thereby increasing their likelihood for clinical success. The identification of treatments that selectively co-inhibit cancerous cell populations remains a challenge. Here, a machine learning approach, scTherapy, leverages single-cell transcriptomic profiles to prioritize multi-targeting treatment options for individual patients with hematological cancers or solid tumors. [ABSTRACT FROM AUTHOR]

Abstract Molecular and functional profiling of cancer cell lines is subject to laboratory‐specific experimental practices and data analysis protocols. The current challenge therefore is how to make an integrated use of the omics profiles of cancer cell lines for reliable biological discoveries. Here, we carried out a systematic analysis of nine types of data modalities using meta‐analysis of 53 omics studies across 12 research laboratories for 2,018 cell lines. To account for a relatively low consistency observed for certain data modalities, we developed a robust data integration approach that identifies reproducible signals shared among multiple data modalities and studies. We demonstrated the power of the integrative analyses by identifying a novel driver gene, ECHDC1, with tumor suppressive role validated both in breast cancer cells and patient tumors. The multi‐modal meta‐analysis approach also identified synthetic lethal partners of cancer drivers, including a co‐dependency of PTEN deficient endometrial cancer cells on RNA helicases.

Abstract Cellular DNA barcoding has become a popular approach to study heterogeneity of cell populations and to identify clones with differential response to cellular stimuli. However, there is a lack of reliable methods for statistical inference of differentially responding clones. Here, we used mixtures of DNA‐barcoded cell pools to generate a realistic benchmark read count dataset for modelling a range of outcomes of clone‐tracing experiments. By accounting for the statistical properties intrinsic to the DNA barcode read count data, we implemented an improved algorithm that results in a significantly lower false‐positive rate, compared to current RNA‐seq data analysis algorithms, especially when detecting differentially responding clones in experiments with strong selection pressure. Building on the reliable statistical methodology, we illustrate how multidimensional phenotypic profiling enables one to deconvolute phenotypically distinct clonal subpopulations within a cancer cell line. The mixture control dataset and our analysis results provide a foundation for benchmarking and improving algorithms for clone‐tracing experiments.

Glioblastoma is the most common primary brain tumor in adults, characterized by an inherent aggressivity and resistance to treatment leading to poor prognoses. While some resistance mechanisms have been elucidated, a deeper understanding of these mechanisms is needed to increase therapeutic efficacy. In this study we first discovered glial-cell derived neurotrophic factor (GDNF) to be upregulated in patient-derived glioblastoma spheroid cultures after chemotherapeutic temozolomide treatment, through RNA-Seq experiments. Therefore, we investigated the role of the GDNF/GDNF receptor alpha 1 (GFRA1) signaling pathway as a resistance mechanism to chemotherapy with temozolomide and lomustine, as well as irradiation using patient-derived glioblastoma spheroid cultures. With qPCR experiments we showed a consistent upregulation of GDNF and its primary receptor GFRA1 following all three lines of treatment. Moreover, CRISPR/Cas9 knock-outs of GDNF in two patient-derived models sensitized these cells to chemotherapy treatment, but not radiotherapy. The increased sensitivity was completely reversed by the addition of exogeneous GDNF, confirming the key role of this factor in chemoresistance. Finally, a CRISPR KO of GFRA1 demonstrated a similar increased sensitivity to temozolomide and lomustine treatment, as well as radiotherapy. Together, our findings support the role of the GDNF/GFRA1 signaling pathway in glioblastoma chemo and radioresistance. [ABSTRACT FROM AUTHOR]

Background: Treatment for resectable oral cavity cancer (OCC) often includes combinations of surgery and radiotherapy (RT), but there is no conclusive information on the preferred treatment order. The aim of this study was to assess the costs and cost-effectiveness of two alternative treatment regimens for patients with OCC, reflecting pre- and post-operative RT, from a societal perspective. Methods: The study used data from the ARTSCAN 2 randomised controlled trial, which compares pre-operative accelerated RT with post-operative conventionally fractionated RT. Two-hundred-forty patients were included in the analysis of treatment outcomes. Direct costs were retrieved from the hospital's economic systems, while indirect costs were obtained from national registries. Cost-effectiveness was assessed and a sensitivity analysis was performed. Overall survival (OS) at 5 years, was used as effect measure in the analysis. Results: Two-hundred-nine patients completed the treatments and had retrievable data on costs. Mean direct costs (inpatient and outpatient care) were € 47,377 for pre-operative RT and € 39,841 for post-operative RT (p = 0.001), while corresponding indirect costs were € 19,854 and € 20,531 (p = 0.89). The incremental cost, i.e., the mean difference in total cost between the treatment regimens, was € 6859 paralleled with a 14-percentage point lower OS-rate at 5 years for pre-operative RT (i.e., 58 vs. 72%). Thus, pre-operative RT was dominated by post-operative RT. Conclusions: From a societal perspective, post-operative RT for patients with resectable OCC is the dominant strategy compared to pre-operative RT. [ABSTRACT FROM AUTHOR]

Radiation therapy (RT) increases tumor response to CTLA-4 inhibition (CTLA4i) in mice and in some patients, yet deep responses are rare. To identify rational combinations of immunotherapy to improve responses we use models of triple negative breast cancer highly resistant to immunotherapy in female mice. We find that CTLA4i promotes the expansion of CD4+ T helper cells, whereas RT enhances T cell clonality and enriches for CD8+ T cells with an exhausted phenotype. Combination therapy decreases regulatory CD4+ T cells and increases effector memory, early activation and precursor exhausted CD8+ T cells. A combined gene signature comprising these three CD8+ T cell clusters is associated with survival in patients. Here we show that targeting additional immune checkpoints expressed by intratumoral T cells, including PD1, is not effective, whereas CD40 agonist therapy recruits resistant tumors into responding to the combination of RT and CTLA4i, indicating the need to target different immune compartments. Radiation therapy (RT) has been shown to improve responses to immunotherapy in preclinical cancer models, but deep responses in patients are still rare. Here the authors provide immunological insights into the response to RT and CTLA4 inhibition in tumor bearing mice and show that agonistic CD40 therapy improves response to the combination of RT and immune checkpoint inhibition. [ABSTRACT FROM AUTHOR]

Therapeutic resistance to kinase inhibitors constitutes a major unresolved clinical challenge in cancer and especially in glioblastoma. Multi-kinase inhibitors may be used for simultaneous targeting of multiple target kinases and thereby potentially overcome kinase inhibitor resistance. However, in most cases the identification of the target kinases mediating therapeutic effects of multi-kinase inhibitors has been challenging. To tackle this important problem, we developed an actionable targets of multi-kinase inhibitors (AToMI) strategy and used it for characterization of glioblastoma target kinases of staurosporine derivatives displaying synergy with protein phosphatase 2A (PP2A) reactivation. AToMI consists of interchangeable modules combining drug-kinase interaction assay, siRNA high-throughput screening, bioinformatics analysis, and validation screening with more selective target kinase inhibitors. As a result, AToMI analysis revealed AKT and mitochondrial pyruvate dehydrogenase kinase PDK1 and PDK4 as kinase targets of staurosporine derivatives UCN-01, CEP-701, and K252a that synergized with PP2A activation across heterogeneous glioblastoma cells. Based on these proof-of-principle results, we propose that the application and further development of AToMI for clinically applicable multi-kinase inhibitors could provide significant benefits in overcoming the challenge of lack of knowledge of the target specificity of multi-kinase inhibitors. [ABSTRACT FROM AUTHOR]

The FDA recently approved eight targeted therapies for acute myeloid leukemia (AML), including the BCL-2 inhibitor venetoclax. Maximizing efficacy of these treatments requires refining patient selection. To this end, we analyzed two recent AML studies profiling the gene expression and ex vivo drug response of primary patient samples. We find that ex vivo samples often exhibit a general sensitivity to (any) drug exposure, independent of drug target. We observe that this "general response across drugs" (GRD) is associated with FLT3-ITD mutations, clinical response to standard induction chemotherapy, and overall survival. Further, incorporating GRD into expression-based regression models trained on one of the studies improved their performance in predicting ex vivo response in the second study, thus signifying its relevance to precision oncology efforts. We find that venetoclax response is independent of GRD but instead show that it is linked to expression of monocyte-associated genes by developing and applying a multi-source Bayesian regression approach. The method shares information across studies to robustly identify biomarkers of drug response and is broadly applicable in integrative analyses. [ABSTRACT FROM AUTHOR]

Cellular DNA barcoding has become a popular approach to study heterogeneity of cell populations and to identify clones with differential response to cellular stimuli. However, there is a lack of reliable methods for statistical inference of differentially responding clones. Here, we used mixtures of DNA‐barcoded cell pools to generate a realistic benchmark read count dataset for modelling a range of outcomes of clone‐tracing experiments. By accounting for the statistical properties intrinsic to the DNA barcode read count data, we implemented an improved algorithm that results in a significantly lower false‐positive rate, compared to current RNA‐seq data analysis algorithms, especially when detecting differentially responding clones in experiments with strong selection pressure. Building on the reliable statistical methodology, we illustrate how multidimensional phenotypic profiling enables one to deconvolute phenotypically distinct clonal subpopulations within a cancer cell line. The mixture control dataset and our analysis results provide a foundation for benchmarking and improving algorithms for clone‐tracing experiments. Synopsis: The study present DEBRA (DESeq‐based Barcode Representation Analysis), an algorithm that enables reliable detection of differentially represented clonal lineages from DNA barcoding experiments by accounting for the statistical properties intrinsic to the barcode read count data. Tagwise variance and other distributional characteristics of the barcode read count data in cellular DNA barcoding experiments are affected by sampling bottleneck, which is not taken into account by traditional analysis tools.DEBRA allows reliable detection of differentially represented clones under a wide range of bottleneck sizes and other experimental conditions.Multidimensional phenotypic profiling is introduced as a novel application of cellular DNA barcoding for inferring phenotypically distinct clonal subpopulations in heterogeneous samples. [ABSTRACT FROM AUTHOR]

Accurate quantification of drug effects is crucial for identifying pharmaceutically actionable cancer vulnerabilities. Current cell viability-based measurements often lead to biased response estimates due to varying growth rates and experimental artifacts that explain part of the inconsistency in high-throughput screening results. We developed an improved drug scoring model, normalized drug response (NDR), which makes use of both positive and negative control conditions to account for differences in cell growth rates, and experimental noise to better characterize drug-induced effects. We demonstrate an improved consistency and accuracy of NDR compared to existing metrics in assessing drug responses of cancer cells in various culture models and experimental setups. Notably, NDR reliably captures both toxicity and viability responses, and differentiates a wider spectrum of drug behavior, including lethal, growth-inhibitory and growth-stimulatory modes, based on a single viability readout. The method will therefore substantially reduce the time and resources required in cell-based drug sensitivity screening. Abhishekh Gupta et al. present a normalized drug response (NDR) metric for accurate quantification of drug sensitivity in cell-based high-throughput assays. They show that NDR captures both toxicity and viability responses to improve drug effect classification over existing methods. [ABSTRACT FROM AUTHOR]

Background: Heterogeneity and low incidence comprise the biggest challenge in sarcoma diagnosis and treatment. Chemotherapy, although efficient for some sarcoma subtypes, generally results in poor clinical responses and is mostly recommended for advanced disease. Specific genomic aberrations have been identified in some sarcoma subtypes but few of them can be targeted with approved drugs.Methods: We cultured and characterised patient-derived sarcoma cells and evaluated their sensitivity to 525 anti-cancer agents including both approved and non-approved drugs. In total, 14 sarcomas and 5 healthy mesenchymal primary cell cultures were studied. The sarcoma biopsies and derived cells were characterised by gene panel sequencing, cancer driver gene expression and by detecting specific fusion oncoproteins in situ in sarcomas with translocations.Results: Soft tissue sarcoma cultures were established from patient biopsies with a success rate of 58%. The genomic profile and drug sensitivity testing on these samples helped to identify targeted inhibitors active on sarcomas. The cSrc inhibitor Dasatinib was identified as an active drug in sarcomas carrying chromosomal translocations. The drug sensitivity of the patient sarcoma cells ex vivo correlated with the response to the former treatment of the patient.Conclusions: Our results show that patient-derived sarcoma cells cultured in vitro are relevant and practical models for genotypic and phenotypic screens aiming to identify efficient drugs to treat sarcoma patients with poor treatment options. [ABSTRACT FROM AUTHOR]

Summary: Magnesium has a key role in osteoporosis and could enhance implant osseointegration in osteoporotic patients. Titanium implants impregnated with Mg ions were installed in the tibia of ovariectomized rats. The release of Mg induced a significant increase of bone formation and the expression of anabolic markers in the peri-implant bone. Introduction: The success of endosseous implants is highly predictable in patients possessing normal bone status, but it may be impaired in patients with osteoporosis. Thus, the application of strategies that adjuvate implant healing in compromized sites is of great interest. Magnesium has a key role in osteoporosis prevention and it is an interesting candidate for this purpose. In this study, the cellular and molecular effects of magnesium release from implants were investigated at the early healing stages of implant integration. Methods: Osteoporosis was induced in 24 female rats by means of ovariectomy and low-calcium diet. Titanium mini-screws were coated with mesoporous titania films and were loaded with magnesium (test group) or left as native (control group). The implants were inserted in the tibia and femur of the rats. One, 2 and 7 days after implantation, the implants were retrieved and histologically examined. In addition, expression of genes was evaluated in the peri-implant bone tissue at day 7 by means of quantitative polymerase chain reactions with pathway-oriented arrays. Results: The histological evaluation revealed that new bone formation started already during the first week of healing for both groups. However, around the test implants, new bone was significantly more abundant and spread along a larger surface of the implants. In addition, the release of magnesium induced a significantly higher expression of BMP6. Conclusions: These results provide evidence that the release of magnesium promoted rapid bone formation and the activation of osteogenic signals in the vicinity of implants placed in osteoporotic bone. [ABSTRACT FROM AUTHOR]

The temporal occurrence, spatial distribution, spread, and prevalence of rabies in Arctic foxes, Vulpes lagopus, in Greenland were studied using historical observations from 1969 to 2011 and survey data collected in the winters 1992 and 1993. Regionally, the prevalence of rabies ranged between 0 and 7.1 %. Wavelet analysis was used to identify periodicities in the abundance of rabies cases based on the historical observations. No general length of the cyclic interval of rabies occurrences in Greenland could be demonstrated. The frequency of outbreaks was found to be variable but can be grouped as short (less than 5 years), medium (5-10 years), and long (more than 10 years). Moreover, rabies outbreaks in neighboring regions were found to be more closely correlated compared to regions further apart. In West Greenland, the temporal outbreaks of rabies were found to occur along a north-south trajectory. [ABSTRACT FROM AUTHOR]

The BCR-ABL1 fusion gene is a driver oncogene in chronic myeloid leukaemia and 30-50% of cases of adult acute lymphoblastic leukaemia. Introduction of ABL1 kinase inhibitors (for example, imatinib) has markedly improved patient survival, but acquired drug resistance remains a challenge. Point mutations in the ABL1 kinase domain weaken inhibitor binding and represent the most common clinical resistance mechanism. The BCR-ABL1 kinase domain gatekeeper mutation Thr315Ile (T315I) confers resistance to all approved ABL1 inhibitors except ponatinib, which has toxicity limitations. Here we combine comprehensive drug sensitivity and resistance profiling of patient cells ex vivo with structural analysis to establish the VEGFR tyrosine kinase inhibitor axitinib as a selective and effective inhibitor for T315I-mutant BCR-ABL1-driven leukaemia. Axitinib potently inhibited BCR-ABL1(T315I), at both biochemical and cellular levels, by binding to the active form of ABL1(T315I) in a mutation-selective binding mode. These findings suggest that the T315I mutation shifts the conformational equilibrium of the kinase in favour of an active (DFG-in) A-loop conformation, which has more optimal binding interactions with axitinib. Treatment of a T315I chronic myeloid leukaemia patient with axitinib resulted in a rapid reduction of T315I-positive cells from bone marrow. Taken together, our findings demonstrate an unexpected opportunity to repurpose axitinib, an anti-angiogenic drug approved for renal cancer, as an inhibitor for ABL1 gatekeeper mutant drug-resistant leukaemia patients. This study shows that wild-type proteins do not always sample the conformations available to disease-relevant mutant proteins and that comprehensive drug testing of patient-derived cells can identify unpredictable, clinically significant drug-repositioning opportunities. [ABSTRACT FROM AUTHOR]

Adoptive infusion of natural killer (NK) cells is being increasingly explored as a therapy in patients with cancer, although clinical responses are thus far limited to patients with hematological malignancies. Inadequate homing of infused NK cells to the tumor site represents a key factor that may explain the poor anti-tumor effect of NK cell therapy against solid tumors. One of the major players in the regulation of lymphocyte chemotaxis is the chemokine receptor chemokine (C-X-C motif) receptor 3 (CXCR3) which is expressed on activated NK cells and induces NK cell migration toward gradients of the chemokine (C-X-C motif) ligand (CXCL9, 10 and 11). Here, we show that ex vivo expansion of human NK cells results in a tenfold increased expression of the CXCR3 receptor compared with resting NK cells ( p = 0.04). Consequently, these NK cells displayed an improved migratory capacity toward solid tumors, which was dependent on tumor-derived CXCL10. In xenograft models, adoptively transferred NK cells showed increased migration toward CXCL10-transfected melanoma tumors compared with CXCL10-negative wild-type tumors, resulting in significantly reduced tumor burden and increased survival (median survival 41 vs. 32 days, p = 0.03). Furthermore, administration of interferon-gamma locally in the tumor stimulated the production of CXCL10 in subcutaneous melanoma tumors resulting in increased infiltration of adoptively transferred CXCR3-positive expanded NK cells. Our findings demonstrate the importance of CXCL10-induced chemoattraction in the anti-tumor response of adoptively transferred expanded NK cells against solid melanoma tumors. [ABSTRACT FROM AUTHOR]

We developed a systematic algorithmic solution for quantitative drug sensitivity scoring (DSS), based on continuous modeling and integration of multiple dose-response relationships in high-throughput compound testing studies. Mathematical model estimation and continuous interpolation makes the scoring approach robust against sources of technical variability and widely applicable to various experimental settings, both in cancer cell line models and primary patient-derived cells. Here, we demonstrate its improved performance over other response parameters especially in a leukemia patient case study, where differential DSS between patient and control cells enabled identification of both cancer-selective drugs and drug-sensitive patient sub-groups, as well as dynamic monitoring of the response patterns and oncogenic driver signals during cancer progression and relapse in individual patient cells ex vivo. An open-source and easily extendable implementation of the DSS calculation is made freely available to support its tailored application to translating drug sensitivity testing results into clinically actionable treatment options. [ABSTRACT FROM AUTHOR]

The proteasome inhibitor bortezomib simultaneously renders tumor cells sensitive to killing by natural killer (NK) cells and resistant to killing by tumor-specific T cells. Here, we show that b-AP15, a novel inhibitor of proteasome deubiquitinating activity, sensitizes tumors to both NK and T cell-mediated killing. Exposure to b-AP15 significantly increased the susceptibility of tumor cell lines of various origins to NK ( p < 0.0002) and T cell ( p = 0.02)-mediated cytotoxicity. Treatment with b-AP15 resulted in increased tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor-2 expression ( p = 0.03) and decreased cFLIP expression in tumor cells in vitro. In tumor-bearing SCID/Beige mice, treatment with b-AP15 followed by infusion of either human NK cells or tumor-specific T cells resulted in a significantly delayed tumor progression compared with mice treated with NK cells ( p = 0.006), T cells ( p < 0.0001) or b-AP15 alone ( p = 0.003). Combined infusion of NK and T cells in tumor-bearing BALB/c mice following treatment with b-AP15 resulted in a significantly prolonged long-term survival compared with mice treated with b-AP15 and NK or T cells ( p ≤ 0.01). Our findings show that b-AP15-induced sensitization to TRAIL-mediated apoptosis could be used as a novel strategy to augment the anticancer effects of adoptively infused NK and T cells in patients with cancer. [ABSTRACT FROM AUTHOR]

Purpose: Predictive strategies for the treatment efficacy of cetuximab are currently not available for head and neck cancer. We investigated the correlation between the expression of epidermal growth factor receptor (EGFR) ligands and EGFR expression, and the growth inhibitory activity of cetuximab in a panel of head and neck squamous cell carcinoma (HNSCC) cell lines. Methods: The growth inhibiting effect of cetuximab was measured for eight HNSCC cell lines and correlated with the autocrine production of five EGFR ligands as measured by ELISA, and the mRNA expression of two ligands, as measured by quantitative RT-PCR. EGFR expression was assessed by western blot analysis. Results: There was a good correlation between the expression of four of the EGFR ligands (TGF-α, amphiregulin, epiregulin and epigen) and the growth inhibiting effect of cetuximab. TGF-α had the highest predictive potential but had to be combined with epigen for full prediction. EGFR expression also correlated with cetuximab sensitivity but less clearly. Conclusions: The results indicate that the expression of several EGFR ligands has to be used to predict sensitivity to cetuximab in HNSCC. This has to be further evaluated in clinical samples. [ABSTRACT FROM AUTHOR]

Purpose: Early metabolic response with a decrease in glucose demand after cytotoxic treatment has been reported to precede tumor volume shrinkage. However, preclinical studies report of a very early rise in metabolism, a flare, following treatment. To elucidate these observations, we performed an experimental study on early metabolic response with sequential analysis of metabolic changes. Methods: Three squamous cell carcinoma cell lines and one nontumorigenic cell line were exposed to cisplatin. The uptake of the fluorescent glucose analogue 2-NBDG was examined at days 1-6 using fluorescence microscopy. The relation between 2-NBDG-uptake and cell survival was evaluated. Results: The tumor cells exhibited a high uptake of 2-NBDG, whereas the uptake in the nonmalignant cells was low. The more cisplatin sensitive cell lines exhibited a more pronounced metabolic flare than the less sensitive cell line. Conclusion: A metabolic flare was a very early sign of treatment response and potentially it could be used as an early marker of treatment sensitivity. [ABSTRACT FROM AUTHOR]

The snowy owl (Bubo scandiacus) is a nomadic species with a circumpolar distribution. It has recently declined in the western Palearctic and may thus be worthy of special consideration for conservation. We investigated genetic structure in three well separated geographic regions within the snowy owls' breeding range. We sequenced two mitochondrial genes; the control region and cytochrome b, and two Z-chromosome introns; VLDLR-9 and BRM-15. We found no phylogeographic structure among the sampled regions, indicating high levels of gene flow in the recent past and possibly still today. Intra-population diversity did not vary between regions for the control region, but for Cyt b, North American birds had higher haplotype diversity than Scandinavian and eastern Siberian birds. Western Palearctic birds do not seem to be genetically deprived or inbred. Genetic diversity in the snowy owl was not lower than Scandinavian populations of three other owl species: tawny owls (Strix aluco), Tengmalm's owls (Aegolius funereus) and eagle owls (Bubo bubo). [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effect of epidermal growth factor receptor (EGFR) blockade on cell survival and on downstream signalling pathways using the monoclonal antibody cetuximab. We used three colon cancer cell lines, of which one was EGFR-negative, and two head and neck squamous cell carcinoma (HNSCC) lines. EGFR expression and gene copy number were measured by immunohistochemistry and FISH analysis, respectively. The effect of cetuximab, irradiation or the combination of both on cell growth was estimated by SRB assay. Western blotting was used to determine the phosphorylation of intracellular signalling proteins and cell cycle phase distribution was measured by flow cytometry. The addition of cetuximab had only limited effects on cell growth, with a maximum inhibition of approximately 30%, but was correlated with the amount of protein expression and gene copy number of EGFR. When combined with irradiation, the effect of cetuximab was only additive and not dependent on the inherent radio-sensitivity of the cell lines. Persistent phosphorylation of Akt and/or p44/42 MAPK was detected by western blot in all of the cell lines, whereas there was no phosphorylation of Jak2 or STAT3. None of these factors alone could predict the sensitivity to cetuximab. Rather, the results suggest that it might be necessary to determine the activation status of several intracellular signalling proteins to better predict the sensitivity to cetuximab treatment. [ABSTRACT FROM AUTHOR]

The aim of the present study was to compare the nucleating behaviour on four types of bioactive surfaces by using the simulated body fluid (SBF) model with the presence albumin. Titanium discs were blasted (B) and then prepared by alkali and heat treatment (AH), anodic oxidation (AO), fluoridation (F), or hydroxyapatite coating (HA). The discs were immersed in SBF with 4.5 mg/ml albumin for 3 days, 1, 2, 3 and 4 weeks and analysed with scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDX) and X-ray photoelectron spectroscopy (XPS). Topographic surface characterisation was performed with a contact stylus profilometer. The results demonstrated that the bioactive surfaces initiated an enhanced calcium phosphate (CaP) formation and a more rapid increase of protein content was present on the bioactive surfaces compared to the blasted control surface. The observation was present on all bioactive surfaces. The fact that there was a difference between the bioactive surfaces and the blasted control surface with respect to precipitation of CaP and protein content on the surfaces support the fact that there may be biochemical advantages in vivo by using a bioactive surface. [ABSTRACT FROM AUTHOR]

We investigated the genetic structure of the presumably small (10–100 pairs) and isolated dunlin ( Calidris alpina) population breeding in Svalbard, and compared it with similar data recently published from several dunlin populations in the western Palearctic and East Greenland. Using mitochondrial and nuclear DNA markers, as well as data on bill lengths, we sought to infer the phylogeographic origin of Svalbard dunlins and assess their within-population level of genetic diversity. Only dunlins with haplotypes of the European mtDNA clade (EUR) were found in Svalbard, indicating a close resemblance to dunlin populations in East Greenland and Iceland. Microsatellite data for Svalbard dunlins, as well as their short bills, also supported a western origin. The Svalbard population did not show signs of inbreeding or reduced levels of genetic diversity compared to other investigated populations, which suggests that the population was recently founded or is currently subject to considerable gene flow. [ABSTRACT FROM AUTHOR]

The aim of the present study was to compare the nucleating and growing behaviour on four types of bioactive surfaces by using the simulated body fluid (SBF) model. Titanium discs were blasted and then prepared by alkali and heat treatment, anodic oxidation, fluoridation, or hydroxyapatite coating. The discs were immersed in SBF for 1, 2, 4 and 6 weeks. Calcium phosphates were found on all specimens, as analysed with scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDX). After 1 and 2 weeks of SBF immersion more titanium was accessible with SEM/EDX on the blasted surfaces than the four bioactive surface types, indicating a difference in coverage by calcium phosphates. The Ca/P mean ratio of the surfaces was approximately 1.5 after 1 week, in contrast to the fluoridated specimens which displayed a Ca/P mean ratio of approximately 2. Powder X-ray diffraction (P-XRD) analyses showed the presence of hydroxyapatite on all types of surfaces after 4 and 6 weeks of immersion. The samples immersed for 6 weeks showed a higher degree of crystallinity than the samples immersed for 4 weeks. In conclusion, differences appeared at the early SBF immersion times of 1 and 2 weeks between controls and bioactive surface types, as well as between different bioactive surface types. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate some bioassays that are different in principle: cell counting, colony forming assay, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT), sulforhodamine B (SRB), crystal violet, and alamarBlue, with respect to their ability to measure cisplatin-induced cell death of in vitro-cultivated squamous cell carcinoma of the head and neck (SCCHN). Cisplatin was applied in concentrations of 1.0, 5.0, 10.0, 50.0, and 100 μ M. The cells were incubated for 1 h, and the cell survival was measured 5 d after treatment. We found the colorimetric assays and cell counting to be comparable. The colony forming assay indicated a higher degree of cell kill compared with the other techniques. Measurement of cell survival after treatment with cisplatin can be done by use of any of the above tested assays. However, the majority of SCCHN cell lines available do not form colonies easily, or at all. Therefore, comparing the chemosensitivity between such cell lines is limited to alternative assays. In this respect, any of the tested colorimetric assays can be used. However, they seem to underestimate cell kill. Cell counting is also an alternative. This technique, however, is time consuming and operator dependent, as in the case of manual counting, or relatively expensive when counting is performed electronically, compared with the colorimetric assays. [ABSTRACT FROM AUTHOR]

Sex differences in the quality and quantity of food loads brought to little auk ( Alle alle) chicks were investigated in a large colony in Hornsund (South Spitsbergen). Adults returning to the colony were caught in mist-nets and food loads were taken from their gular pouch. The sex of each bird was determined by means of molecular methods. Females brought significantly more food per single load than males in terms of wet weight (30% more on average), number of prey items (46%) and energy contents (39%). However, there was no difference between the sexes in the size of prey taken. Energy-rich Calanus glacialis, originating from cold Arctic waters, was the most frequent prey item and made up the majority of food loads brought by both males and females (75 and 72%, respectively). This indicates that both sexes forage mainly in Arctic waters. However, differences in the proportion of cold water Calanus species ( C. glacialis and C. hyperboreus), warm water Calanus species ( C. finmarchicus), as well as other taxa, between males and females may suggest different ways of exploiting the feeding area. [ABSTRACT FROM AUTHOR]

Migratory connectivity plays an important role in conservation of long-distance migrant birds. Here, we study migratory links of dunlin (Calidris alpina), focusing on a stopover and wintering region (Portugal) where it is known that migration routes of dunlin from a broad geographic range (three subspecies) converge, and populations occur simultaneously or separated in time. We combine three methods (ringing recoveries, morphometrics and molecular genetics) to assess breeding origins and extent of temporal segregation of dunlin assemblages. Ringing recoveries show temporal separation of dunlin from different migration routes. Birds found in Portugal during August and September, migrating via Britain, reveal links to breeding areas in Iceland and Greenland. In October, a clear shift to more eastern migration routes occurs, with most Portuguese winter records from stopover sites along migration routes of populations from northern Scandinavia and Russia. Mitochondrial DNA (mtDNA) of Portuguese dunlin was compared with breeding populations. Spring and autumn migrants in Portugal corresponded to C. a. schinzii and C. a. arctica populations, while the Portuguese winter population clearly differs by including mtDNA haplotypes of C. a. alpina. For genetically sexed individuals, we found significant differences in morphology (bill and tarsus length) supporting the temporal separation of populations/subspecies revealed by recoveries and mtDNA. Our results give evidence for migratory connectivity of dunlin populations between geographic areas previously not considered connected. They confirm the existence of clear differences in breeding origin between birds in Portugal at different times of year. These results are important in the consideration of future long-term conservation plans. [ABSTRACT FROM AUTHOR]

Randomly amplified polymorphic DNA (RAPD) markers were used to assign individual adult sockeye salmon to their spawning sites using a genotype assignment test. Six primers were selected for use by screening bulked DNA samples for markers missing in fish from one or more of 5 sites in British Columbia or Alaska. Of 73 markers scored, 54 showed variation between or within sites among the sampled fish. Thirty-seven of the variable markers were not detected in any fish from one or more sites; 18 variable markers were detected in all fish from one or more other sites. Thus 25% of markers scored were found in all fish of some sites and in no fish of some other sites. An assignment test placed all 70 fish tested into their correct populations. Principal coordinate analysis of genetic variation produced clusters of fish corresponding to each sampling site. No sex-specific RAPD markers were detected among more than 1300 screened. [ABSTRACT FROM AUTHOR]

The biocompatibility of dental implants coated with titania/hydroxyapatite (HA) and titania/bioactive glass (BG) composites obtained via sol-gel process was investigated using an in vitro and in vivo model. A device for the in vitro testing of screw-shaped dental implants was developed, in order to well compare the two experimental models studying the behavior of human MG63 osteoblast-like cells seeded onto a particular geometry. The expression of some biochemical parameters of osteoblastic phenotype (alkaline phosphatase specific activity, collagen and osteocalcin production) and some indications on cells morphology obtained by scanning electron microscopy were evaluated. The in vitro and in vivo models were compared after implants insertion in rabbit tibia and femur. The removal torque and histomorphometric parameters (percentage of bone in contact with implant surface and the amount of bone inside the threaded area) were examined. A good agreement was found between the in vitro and in vivo models. These experiments showed better performances of HA and BG sol-gel coated dental implants with respect to uncoated titanium; in particular, it was found that in vitro the HA coating stimulates osteoblastic cells in producing higher level of ALP and collagen, whereas in vivo this surface modification resulted in a higher removal torque and a larger bone-implant contact area. This behavior could be ascribed to the morphology and the chemical composition of the implants with rough and bioactive surfaces. [ABSTRACT FROM AUTHOR]

Bone integration of threaded implants made of cured polymethylmethacrylate containing sodium fluoride or commercially pure (c.p.) titanium were studied in normal and estrogen deficient New Zealand white rabbits. Nine had been ovariectomized through laparoscopy and nine served as controls. Four weeks after the ovariectomy two threaded implants made of cured bone cement with or without sodium fluoride addition were inserted in each tibia. One threaded commercially pure titanium implant was inserted in each patello–femoral joint flush to the cartilage. Six weeks after implant insertion measurement of the peak removal torque necessary to loosen the implants and light microscopical histomorphometrical investigations of tissue integration were performed. In the ovariectomized rabbits addition of sodium fluoride to the cement resulted in increased area of bone in the threads (p=0.04), but no corresponding effect could be noted in the controls. The removal torque was lower in the ovariectomized rabbits compared to the non-ovariectomized when comparing implant with sodium fluoride addition (p=0.02). The bone tissue response and the removal torque of the titanium implants were not influenced by ovariectomy in these rabbits. ©2002 Kluwer Academic Publisher [ABSTRACT FROM AUTHOR]

The addition of sodium fluoride to poly (methyl-methacrylate) (PMMA) bone cement may theoretically improve the fixation of joint replacement. This hypothesis was tested in an animal model using nine mature healthy lop-eared rabbits. A femoral prosthesis was inserted in both knees to resurface the patellofemoral articulation. The same acrylic cement, with and without sodium fluoride, was randomised between the two sides for prosthetic fixation. Two screw shaped implants machined from cured rods of either cement were also inserted bilaterally into the proximal tibia. Qualitative and quantitative histomorphometry of the bone tissue response surrounding the cement in the femur and the intact tibial implants revealed similar results regardless of sodium fluoride addition. Six weeks after surgery removal, torque did not significantly differ between the two sides. Our findings indicate that addition of sodium fluoride to PMMA has little effect on implant stability and bone remodeling in rabbits in the short-term. [ABSTRACT FROM AUTHOR]

We studied the population structure of a high arctic breeding wader bird species, the White-rumped Sandpiper Calidris fuscicollis. Breeding adults, chicks and juveniles were sampled at seven localities throughout the species' breeding range in arctic Canada in 1999. The mitochondrial control region was analysed by DNA sequencing, feathers were analysed for carbon isotope ratios (C13/C12) by isotope ratio mass spectrometry, and morphological measurements were analysed using principal component analyses, taking the effect of sex into account (identified by molecular genetic methods). In general, our results support the notion that the White-rumped Sandpiper is a monotypic species with no subspecies, and most of the morphological and genetic variation occurs within sites. Nevertheless, some differences between sites were found. Birds from the two northernmost sites (Ellesmere and Devon Islands) had relatively longer bill and wing and shorter tarsus than birds sampled further south, possibly reflecting genetic differences between populations. The carbon isotope ratios were higher at the easternmost site (Baffin Island), revealing differences in the isotope content of the food. The mtDNA sequences showed no significant differentiation between sites and no pattern of isolation-by-distance was found. Based on the mtDNA variation, the species was estimated to have a long-term effective population size of approximately 9,000 females. The species shows no clear evidence of any population expansion or decline. Our results indicate that carbon isotope ratios, and possibly also certain mtDNA haplotypes, may be useful as tools for identifying the breeding origin of White-rumped Sandpipers on migration and wintering sites. [ABSTRACT FROM AUTHOR]

Surface oxide properties are regarded to be of great importance in establishing successful osseointegration of titanium implants. Despite a large number of theoretical questions on the precise role of oxide properties of titanium implants, current knowledge obtained from in vivo studies is lacking. The present study is designed to address two aspects. The first is to verify whether oxide properties of titanium implants indeed influence the in vivo bone tissue responses. The second, is to investigate what oxide properties underline such bone tissue responses. For these purposes, screw-shaped/turned implants have been prepared by electrochemical oxidation methods, resulting in a wide range of oxide properties in terms of: (i) oxide thickness ranging from 200 to 1000 nm, (ii) the surface morphology of barrier and porous oxide film structures, (iii) micro pore configuration – pore sizes<8 μm by length, about 1.27 μ2 to 2.1 μm2 by area and porosity of about 12.7–24.4%, (iv) the crystal structures of amorphous, anatase and mixtures of anatase and rutile type, (v) the chemical compositions of TiO2 and finally, (vi) surface roughness of 0.96–1.03 μm (Sa). These implant oxide properties were divided into test implant samples of Group II, III, IV and V. Control samples (Group I) were turned commercially pure titanium implants. Quantitative bone tissue responses were evaluated biomechanically by resonance frequency analysis (RFA) and removal torque (RT) test. Quantitative histomorphometric analyses and qualitative enzyme histochemical detection of alkaline (ALP) and acidic phosphatase (ACP) activities were investigated on cut and ground sections after six weeks of implant insertion in rabbit tibia. In essence, from the biomechanical and quantitative histomorphometric measurements we concluded that oxide properties of titanium implants, i.e. the oxide thickness, the microporous structure, and the crystallinity significantly influence the bone tissue response. At this stage, however, it is not clear whether oxide properties influence the bone tissue response separately or synergistically. © 2001 Kluwer Academic Publishers [ABSTRACT FROM AUTHOR]

Studies of how organisms are adapted to regional climatic conditions are valuable when predicting the effects of global climatic changes on biota. Here we report on the geographical variation in timing of breeding and moult of an Arctic breeding wader, the dunlin (Calidris alpina). The Palearctic study sites range latitudinally between 68 and 76°N and longitudinally between 46 and 179°E, and encompass a variety of local climates. The sites were visited in sequence from west to east within 1 year, and therefore the data are not affected by confounding interannual variations. The estimated breeding start ranged from 5 to 25 June across populations. Birds at more southern sites were found to breed earlier than those at more northern breeding sites. Within populations, the breeding start for first clutches spanned a period of 8 days and, when including replacement clutches, 3–4 weeks. No dunlin west of the Taimyr Peninsula were found moulting while incubating at the nest, whereas all dunlin on Taimyr Peninsula and eastwards were in active wing moult while incubating or rearing chicks. The onset of moult in these populations ranged from 23 to 27 June. The consequences of geographical variation of breeding conditions for variation in the annual cycle of this species are discussed. [ABSTRACT FROM AUTHOR]

Centromeric rearrangements, in the form of isochromosomes or whole-arm translocations, are the most common recurrent changes in head and neck and skin carcinomas. Little is known about the mechanisms behind the origin of these chromosome rearrangements. In the present study, one basal cell carcinoma and two squamous cell carcinomas of the head and neck were thoroughly studied by cytogenetic and fluorescence in situ hybridization techniques. All tumors showed intratumor heterogeneity in the form of cytogenetically related subclones (in all tumors) and unrelated clones (in one tumor). Assessment of karyotypic evolution in these tumors suggests that centromeric cleavage is a mechanism giving rise to isochromosomes. A similar mechanism may also be involved in the formation of whole-arm translocations. [ABSTRACT FROM AUTHOR]