bluuebunny/crossref_metadata_2025_split huggingface dataset:
SH‐7, a new synthesized shikonin derivative, exerting its potent antitumor activities as a topoisomerase inhibitor
Authors: Yang Fan , Chen Yi , Duan Wenhu , Zhang Chao , Zhu Hong , Ding Jian 
Published: March 2006

Abstract1‐(1,4‐dihydro‐5,8‐dihydroxy‐1,4‐dioxonaphthalen‐2‐yl)‐4‐methylpent‐3‐enylfuran‐2‐caroxylate (SH‐7), a new naphthoquinone compound, derived from shikonin, exhibited obvious inhibitory actions on topoisomerase II (Topo II) and topoisomerase I (Topo I), which were stronger than its mother compound shikonin. Notably, the SH‐7's inhibitory potency on Topo II was much stronger than that on Topo I. In addition, SH‐7 significantly stabilized Topo II‐DNA cleavable complex and elevated the expression of phosphorylated‐H2AX. The in vitro cell‐based investigation demonstrated that SH‐7 displayed wide cytotoxicity in diversified cancer cell lines with the mean IC50 value of 7.75 μM. One important finding is SH‐7 displayed significant cytotoxicity in the 3 MDR cell lines, with an average IC50 value nearly equivalent to that of the corresponding parental cell lines. The average resistance factor (RF) of SH‐7 was 1.74, which was much lower than those of reference drugs VP‐16 (RF 145.92), ADR (RF 105.97) and VCR (RF 197.39). Further studies illustrated that SH‐7 had the marked apoptosis‐inducing function on leukemia HL‐60 cells, which was validated to be of mitochondria‐dependence. The in vivo experiments showed that SH‐7 had inhibitory effects on S‐180 sarcoma implanted to mice, SMMC‐7721, BEL‐7402 human hepatocellular carcinoma and PC‐3 human prostate cancer implanted to nude mice. Taken together, these results suggest that SH‐7 induces DSBs as a Topo II inhibitor, which was crucial to activate the apoptotic process, and subsequently accounts for its both in vitro and in vivo antitumor activities. The well‐defined Topo II inhibitory activity, antitumor effects particularly with its obvious anti‐MDR action, better solubility and less toxicity make SH‐7 as a potential antitumor drug candidate for further research and development. © 2006 Wiley‐Liss, Inc.
Determination of viral load thresholds in cervical scrapings to rule out CIN 3 in HPV 16, 18, 31 and 33‐positive women with normal cytology
Authors: Snijders Peter J.F. , Hogewoning Cornelis J.A. , Hesselink Albertus T. , Berkhof Johannes , Voorhorst Feja J. , Bleeker Maaike C.G. , Meijer Chris J.L.M. 
Published: March 2006

AbstractAn increased high‐risk human papillomavirus (hrHPV) viral load in cervical scrapings has been proposed as a determinant for high‐grade cervical intraepithelial neoplasia (CIN) and cervical cancer (≥CIN 2), but data so far for HPV types different from HPV 16 are limited and inconsistent. In addition, a viral load threshold to distinguish hrHPV positive women without ≥CIN 2 still has not been defined. Here, we used baseline cervical scrapings of women with normal cytology participating in a large population‐based cervical screening trial (i.e. POBASCAM) who were GP5+/6+‐PCR positive for 4 common hrHPV types, i.e. HPV 16, 18, 31 or 33, as a reference to arbitrarily define various viral load thresholds (i.e. 25th, 33rd, 50th, 67th and 75th percentiles of the lowest viral load values) for distinguishing women having single infections with these types without high‐grade CIN. Viral load assessment was performed by real time type‐specific PCR. The viral load threshold values were subsequently validated on abnormal cervical scrapes of 162 women with underlying, histologically confirmed CIN lesions containing 1 of these 4 hrHPV types. All 59 women with CIN 3 had viral load levels that were higher than those of 33% of the women with normal cytology containing the respective hrHPV type detectable by GP5+/6+‐PCR (i.e. higher than the 33rd percentile of viral load). By using this 33rd percentile viral load cut‐off, sensitivity for CIN 3 of 100% (95% CI 93.9–100) was obtained. Hence, application of this viral load threshold would increase the specificity of HPV testing for HPV 16, 18, 31 and 33‐associated prevalent CIN 3 without the cost of a marked reduction in sensitivity. In practice, on the basis of viral load analysis, a less aggressive management can be foreseen for 33% of the women with normal cytology participating in a population‐based screening program who are GP5+/6+‐PCR positive for HPV 16, 18, 31 or 33. © 2006 Wiley‐Liss, Inc.
Chromosome 9 deletions are more frequent than FGFR3 mutations in flat urothelial hyperplasias of the bladder
Authors: van Oers Johanna M.M. , Adam Christoph , Denzinger Stefan , Stoehr Robert , Bertz Simone , Zaak Dirk , Stief Christian , Hofstaedter Ferdinand , Zwarthoff Ellen C. , van der Kwast Theodorus H. , Knuechel Ruth , Hartmann Arndt 
Published: March 2006

AbstractFlat urothelial hyperplasias (FUHs) in patients with papillary bladder tumours frequently show deletions of chromosome 9, suggesting that FUH could be the first neoplastic step in the development of papillary bladder cancer. FGFR3 mutations are frequent in non‐invasive papillary tumours with low risk of progression. Our aim was to investigate the frequency of FGFR3 mutations and deletions of chromosomes 9p/q and 8p/q in FUH. Thirty FUH and 9 simultaneous or consecutive tumours were detected by 5‐ALA‐based photodynamic cystoscopy. DNA was isolated from frozen sections and whole genome amplification was done by I‐PEP‐PCR, followed by LOH analysis on chromosomes 8p/q and 9p/q. FGFR3 mutations were detected by SNaPshot analysis. LOH analysis on FUH revealed deletions at 9p/q (11/30, 37%) and 8p/q (3/30, 10%). FGFR3 mutations were found in 7/30 FUH (23%). Only 2 FUH showed an FGFR3 mutation without deletions of chromosome 9. In contrast, 6 FUH revealed chromosome 9 deletions but wild type FGFR3 (p = 0.03). These results suggest that chromosome 9 deletions are the earliest genetic alterations in bladder cancer. The detection of FGFR3 mutations in FUH further supports the role of this lesion as precursor of papillary bladder cancer. © 2006 Wiley‐Liss, Inc.
Anti‐tumor efficacy of a transcriptional replication‐competent adenovirus, Ad‐OC‐E1a, for osteosarcoma pulmonary metastasis
Authors: Li Xiong , Jung Chaeyong , Liu You‐Hong , Bae Kyung‐hee , Zhang Yan‐Ping , Zhang Hong‐Ji , VanderPutten Dale , Jeng Meei‐Huey , Gardner Thomas A. , Kao Chinghai 
Published: March 2006

AbstractBackgroundOsteosarcoma (OSA) is the most frequent type of primary malignant bone tumor and is apt to occur in children and young adults. Pulmonary metastasis (OSPM) is the major reason for its fatal outcome. Osteocalcin (OC) is a major noncollagenous bone protein whose expression is limited almost exclusively to bone marrow and osteotropic tumors. OC is also known to express in cell lines with bone metastasis feathers. Gene therapy strategies with the OC promoter directing the replication of adenovirus in a tumor‐specific manner are a potential modality for OSPM therapy.MethodsWe detected OC mRNA expression by RNA in situ hybridization in OSA and OSPM samples from patients, and tested OC promoter transcriptional activity in OSA and non‐OSA cell lines. Then we used a transcriptional replication‐competent adenovirus, Ad‐OC‐E1a, to treat OSPM, and evaluated its tumor‐specific replication and killing activities in vitro as well as anti‐OSPM efficacy in vivo via systemic delivery.ResultsOC mRNA was detected in all types of OSA tissues, including OSPM tissues. The transcriptional activity of the OC promoter was much higher in a OSPM cell line SAOS‐2LM7 and primary OSA cell line MG63 than in non‐OSA cell lines, including cell lines from breast cancer, colon cancer, and liver cancer. Ad‐OC‐E1a expressed E1a protein only in MG63 and SAOS‐2LM7, which indicated that adenovirus E1a was under strict control by the OC promoter. Ad‐OC‐E1a demonstrated killing and viral replication activity close to wild‐type adenovirus levels in MG63 and SAOS‐2LM7, but the killing and viral replication activities were attenuated significantly in cells expressing low OC transcriptional activity. To test whether Ad‐OC‐E1a could be used to target human OSPM in vivo, SAOS‐2LM7 pulmonary metastasis models in nude mice were induced and treated by tail‐vein injection with Ad‐OC‐E1a. Compared to tumor nodules in the lung in groups treated with PBS or control virus, the quantity of metastasized tumor nodules decreased significantly. Adenovirus‐infected cells were stained immunohistochemically only inside and around the OSPM nodules but spared normal lung tissue and other organs.ConclusionsThese data demonstrated that OC promoter could direct adenovirus replication by controlling the E1a gene to target human OSPM in a tumor‐specific manner, providing an efficient tool to develop a feasible therapeutic modality for OSPM. Copyright © 2006 John Wiley & Sons, Ltd.
Tendon and neurovascular bundle displacement in the palm with hand flexion and extension: An MRI and gross anatomy correlative study
Authors: Canuto Holly C. , Oliveira Miguel L.R. , Fishbein Kenneth W. , Spencer Richard G. 
Published: March 2006

AbstractThis study evaluated the correlative use of MRI methods and gross anatomy to monitor tendon displacement in the central region of the palm at rest and during flexion and extension of the metacarpophalangeal and interphalangeal joints with respect to the corresponding neurovascular bundles (NVBs). In all of the samples the neutral and extended positions showed the NVB to be palmar with respect to the flexor tendons, while during flexion tendon displacement caused the NVB to be dorsal to both the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) tendons. T1‐weighted MR images correlated with gross anatomical slides demonstrated that significant changes occur in the relative positions of the flexor tendons and associated NVBs of the palm upon flexion and extension. J. Magn. Reson. Imaging 2006. Published 2006 Wiley‐Liss, Inc.
On the Asian expression of the PDO
Authors: D'Arrigo Rosanne , Wilson Rob 
Published: March 2006

AbstractThe causes and mechanisms of Pacific Decadal Variability (PDV) are still being investigated. One reason that such variability is not better understood is the scarcity of high‐resolution paleoclimatic records from the Asian side of the North Pacific. Here we present a reconstruction of the boreal spring (March–May) Pacific Decadal Oscillation (PDO) index, spanning A.D. 1565–1988, that is the first to represent the large‐scale Asian expression of this phenomenon using tree‐ring data. Intervention analysis reveals significant (95% level) regime shifts corresponding to those in the instrumental PDO during the mid‐1920s, mid‐1940s and mid‐1970s, the latter period associated with the famed 1976 shift in Pacific climate. Shifts in the preinstrumental period show varying correspondence with those of a North American‐based tree‐ring reconstruction of the North Pacific index (NPI), another indicator of Pacific decadal climate variability. Differences between these two time series hint at modulation of local climate from Asian monsoon, El Niño‐Southern Oscillation (ENSO) and volcanic forcing, which could be partly masked by combining data from these sensitive regions in future PDO reconstructions. Overall, however, comparison of the reconstructions from both Asia and North America (NA) is useful for evaluating the distinct expressions of the PDO on both sides of the North Pacific and their interactions with the tropics. Copyright © 2006 Royal Meteorological Society.
Remediation of a soil contaminated with heavy metals by immobilizing compounds
Authors: Usman Abdul R. A. , Kuzyakov Yakov , Lorenz Klaus , Stahr Karl 
Published: March 2006

AbstractThe labile fraction of heavy metals (HM) in soils is the most important for toxicity for plants and microorganisms. Thus, it is crucial to reduce this fraction in contaminated soils to decrease the negative effect of HM. In a greenhouse experiment, the effects of several additives on the labile fractions of Zn, Cd, Cu, Ni, and Pb were investigated in a soil contaminated during long‐term sewage‐sludge application. The accumulation of HM was studied in the aboveground biomass of wheat (Triticum aestivum L.). The additives used were the clay minerals Na‐bentonite, Ca‐bentonite, and zeolite; the Fe oxides hematite and goethite; the phosphate fertilizers superphosphate and Novaphos. Wheat was planted three times during 5 months, allowed to grow for 7 w, and harvested. Dry matter and HM content of shoots were determined after each harvest. Soil samples were taken after the first and third harvest, and the NH4NO3‐extractable HM contents were determined.After the addition of 2% Na‐bentonite as well as 2% Ca‐bentonite, a strong reduction of the labile HM soil fraction and shoot HM concentration was observed. At the end of the experiment, the labile fraction was reduced due to the addition of Na‐bentonite and Ca‐bentonite by 24% and 31% for Zn, by 37% and 36% for Cd, by 41% and 43% for Cu, by 54% and 61% for Ni, and by 48% and 41% for Pb, respectively. Furthermore, the shoot HM concentrations with the exception of Zn were reduced below the phytotoxicity range. Accordingly, the shoot dry‐matter production was significantly increased.The addition of phosphate fertilizers (notably Novaphos) strongly reduced the bioavailability of Pb for wheat plants. By addition of 0.05% Novaphos, the labile fraction and the shoot concentration of Pb were lowered by 39% and 64%, respectively. However, the addition of Fe oxides and zeolite resulted only in a small reduction in HM bioavailability to wheat plants. Among the studied additives, Na‐bentonite and Ca‐bentonite have the most promising potential to reduce the bioavailability for the studied HM.
Soil microbial biomass and activity: the effect of site characteristics in humid temperate forest ecosystems
Authors: Friedel Jürgen K. , Ehrmann Otto , Pfeffer Michael , Stemmer Michael , Vollmer Tobias , Sommer Michael 
Published: March 2006

AbstractMicrobial biomass, respiratory activity, and in‐situ substrate decomposition were studied in soils from humid temperate forest ecosystems in SW Germany. The sites cover a wide range of abiotic soil and climatic properties. Microbial biomass and respiration were related to both soil dry mass in individual horizons and to the soil volume in the top 25 cm. Soil microbial properties covered the following ranges: soil microbial biomass: 20 µg C g–1–8.3 mg C g–1 and 14–249 g C m–2, respectively; microbial C–to–total organic C ratio: 0.1%–3.6%; soil respiration: 109–963 mg CO2‐C m–2 h–1; metabolic quotient (qCO2): 1.4–14.7 mg C (g Cmic)–1 h–1; daily in‐situ substrate decomposition rate: 0.17%–2.3%. The main abiotic properties affecting concentrations of microbial biomass differed between forest‐floor/organic horizons and mineral horizons. Whereas microbial biomass decreased with increasing soil moisture and altitude in the forest‐floor/organic horizons, it increased with increasing Ntot content and pH value in the mineral horizons. Quantities of microbial biomass in forest soils appear to be mainly controlled by the quality of the soil organic matter (SOM), i.e., by its C : N ratio, the quantity of Ntot, the soil pH, and also showed an optimum relationship with increasing soil moisture conditions. The ratio of Cmic to Corg was a good indicator of SOM quality. The quality of the SOM (C : N ratio) and soil pH appear to be crucial for the incorporation of C into microbial tissue. The data and functional relations between microbial and abiotic variables from this study provide the basis for a valuation scheme for the function of soils to serve as a habitat for microorganisms.
Nitrogen fertilization and nitrate leaching into groundwater on arable sandy soils
Authors: Köhler Kai , Duynisveld Wilhelmus H. M. , Böttcher Jürgen 
Published: March 2006

AbstractNitrate leaching depending on N fertilization and different crop rotations was studied at two sites with sandy soils in N Germany between 1995 and 2000. The leaching of NO$ _3^- $ was calculated by using a numerical soil‐water and N model and regularly measured Nmin values as input data. Also the variability of Nmin values on the sandy soils was determined along transects. They reveal the high variability of the Nmin values and show that it is not possible to confirm a significant Nmin difference between fertilizer treatments using the normal Nmin‐sampling intensity. Nitrate‐leaching calculations of five leaching periods showed that even strongly reduced N‐fertilizer applications did not result in a substantially lower NO$ _3^- $ leaching into the groundwater. Strong yield reductions of even more than 50%, however, were immediately measured. Mean NO$ _3^- $ concentrations in the groundwater recharge are >50 mg L–1 and are mainly due to mineralization from soil organic matter. Obviously, the adjustment of the N cycle in the soil to a new equilibrium and a reduced NO$ _3^- $‐leaching rate as a consequence of lower N inputs need a much longer time span. Catch crops are the most efficient way to reduce the NO$ _3^- $ concentrations in the groundwater recharge of sandy soils. Their success, however, strongly depends on the site‐specific development possibilities of the catch crop. Even with all possible measures implemented, it will be almost impossible to reach NO$ _3^- $ concentrations <50 mg L–1 in sandy soils. The only way to realize this goal on a regional scale could be by increasing areas with lower nitrate concentrations in the groundwater recharge like grassland and forests.
Anisotropy of pore functions in structured Stagnic Luvisols in the Weichselian moraine region in N Germany
Authors: Dörner José , Horn Rainer 
Published: March 2006

AbstractIn order to determine if soil hydraulic properties present a direction‐dependent behavior, undisturbed samples were collected at different horizons and orientations (vertical, diagonal [45°], and horizontal) in structured soils in the Weichselian moraine region in northern Germany. The water‐retention curve (WRC), the saturated hydraulic conductivity (kf), and the air permeability (ka) were measured. The air‐filled porosity (ϵa) was determined, and pore‐continuity indices (ka/ϵa, ka/ϵa2, N) and blocked porosities (ϵb) were derived from the relationship between ka and ϵa.The development of soil structures with defined forms and dimensions (e.g., platy by soil compaction or prismatic up to subangular‐blocky by swelling–shrinkage processes) and the presence of biopores can induce a direction‐dependent behavior of pore functions. Although the pore volume as a scalar is isotropic, the saturated hydraulic conductivity and air permeability (as a function of air‐filled porosity) can be anisotropic. This behavior was observed in pore‐continuity indices showing that the identification of soil structure can be used as a first parameter to estimate if hydraulic properties present a direction‐dependent behavior at the scale of the soil horizon.
Subglacial bedform evidence for a major palaeo‐ice stream and its retreat phases in Amundsen Gulf, Canadian Arctic Archipelago
Authors: Stokes C. R. , Clark C. D. , Winsborrow M. C. M. 
Published: March 2006

AbstractAscertaining the location of palaeo‐ice streams is crucial in order to produce accurate reconstructions of palaeo‐ice sheets and examine interactions with the ocean–climate system. This paper reports evidence for a major ice stream in Amundsen Gulf, Canadian Arctic Archipelago. Mapping from satellite imagery (Landsat ETM+) and digital elevation models, including bathymetric data, is used to reconstruct flow‐patterns on southwestern Victoria Island and the adjacent mainland (Nunavut and Northwest Territories). Several flow‐sets indicative of ice streaming are found feeding into the marine trough and cross‐cutting relationships between these flow‐sets (and utilising previously published radiocarbon dates) reveal several phases of ice stream activity centred in Amundsen Gulf and Dolphin and Union Strait. A large erosional footprint on the continental shelf indicates that the ice stream (ca. 1000 km long and ca. 150 km wide) filled Amundsen Gulf, probably at the Last Glacial Maximum. Subsequent to this, the ice stream reorganised as the margin retreated back along the marine trough, eventually splitting into two separate low‐gradient lobes in Prince Albert Sound and Dolphin and Union Strait. The location of this major ice stream holds important implications for ice sheet–ocean interactions and specifically, the development of Arctic Ocean ice shelves and the delivery of icebergs into the western Arctic Ocean during the late Pleistocene. Copyright © 2006 John Wiley & Sons, Ltd.
Constraining the age of Lateglacial and early Holocene pollen zones and tephra horizons in southern Sweden with Bayesian probability methods
Authors: Wohlfarth B. , Blaauw M. , Davies S. M. , Andersson M. , Wastegård S. , Hormes A. , Possnert G. 
Published: March 2006

AbstractThe sediment sequence from Hässeldala port in southeastern Sweden provides a unique Lateglacial/early Holocene record that contains five different tephra layers. Three of these have been geochemically identified as the Borrobol Tephra, the Hässeldalen Tephra and the 10‐ka Askja Tephra. Twenty‐eight high‐resolution 14C measurements have been obtained and three different age models based on Bayesian statistics are employed to provide age estimates for the five different tephra layers. The chrono‐ and pollen stratigraphic framework supports the stratigraphic position of the Borrobol Tephra as found in Sweden at the very end of the Older Dryas pollen zone and provides the first age estimates for the Askja and Hässeldalen tephras. Our results, however, highlight the limitations that arise in attempting to establish a robust, chronologically independent lacustrine sequence that can be correlated in great detail to ice core or marine records. Radiocarbon samples are prone to error and sedimentation rates in lake basins may vary considerably due to a number of factors. Any type of valid and ‘realistic’ age model, therefore, has to take these limitations into account and needs to include this information in its prior assumptions. As a result, the age ranges for the specific horizons at Hässeldala port are large and calendar year estimates differ according to the assumptions of the age‐model. Not only do these results provide a cautionary note for over‐dependence on one age‐model for the derivation of age estimates for specific horizons, but they also demonstrate that precise correlations to other palaeoarchives to detect leads or lags is problematic. Given the uncertainties associated with establishing age–depth models for sedimentary sequences spanning the Lateglacial period, however, this exercise employing Bayesian probability methods represents the best possible approach and provides the most statistically significant age estimates for the pollen zone boundaries and tephra horizons. Copyright © 2006 John Wiley & Sons, Ltd.