bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in Soil Organic Carbon Contents and Nitrous Oxide Emissions after Introduction of No‐Till in Pampean Agroecosystems
Authors: Steinbach Haydée S. , Alvarez Roberto
Published: January 2006

We reviewed published results to estimate no‐till effects on SOC and denitrification in the Argentine Pampas and the potential of no‐till to mitigate the global warming effect. On an equivalent mass basis, 42 paired data sets were used for SOC comparisons of no‐till vs. plow till (moldboard plow or disk plow), 18 paired data for comparison of no‐till vs. reduced till (chisel plow or harrow disk), and 20 paired data for comparison of plow till vs. reduced till. Twenty‐six denitrification data sets were used for evaluation of tillage system and fertilization effects on N2O emission. Changes in SOC under no‐till were not correlated to time since initiation of experiments. Averaged over years a 2.76 Mg ha−1 SOC increase (P = 0.01) was observed in no‐till systems compared with tilled systems, but no differences were detected between plow and reduced till. The SOC under tillage explained most of the SOC variation under no‐till (R2 = 0.94, P = 0.01). The model had a positive intercept and predicted a relatively higher increase of SOC in areas of low organic matter level. The conversion of the whole pampean cropping area to no‐till would increase SOC by 74 Tg C, about twice the annual C emissions from fossil fuel consumption of Argentina. Emissions of N2O were greater under no‐till with a mean increase of 1 kg N ha−1 yr−1 in denitrification rate for humid pampean scenarios. The increased emissions of N2O might overcome the mitigation potential of no‐till due to C sequestration in about 35 yr, and therefore no‐till might produce global warming.
Reduction of Stream Sediment Concentration by a Riparian Buffer: Filtering of Road Runoff in Disturbed Headwater Basins of Montane Mainland Southeast Asia
Authors: Ziegler Alan D. , Negishi Junjiro , Sidle Roy C. , Preechapanya Pornchai , Sutherland Ross A. , Giambelluca Thomas W. , Jaiaree Sathaporn
Published: January 2006

We determined the extent that a riparian buffer reduces stream suspended sediment concentrations by filtering road runoff during 18 rain events in a 2.5‐ha, multi‐use watershed in northern Thailand. The dominant buffer species was the perennial sedge Fimbristylis aphylla Zoll. ex Steud. (Cyperaceae). We monitored stream sediment concentration for situations where road runoff either flowed into the riparian buffer or was diverted directly into the stream (buffer and no buffer scenarios). These data were used to develop the following relationships between instantaneous stream sediment concentration (Ci) and discharge (Qi): Ci = 28.329Qi0.851 (buffer scenario) and Ci = 22.265Qi1.579 (no buffer scenario). Using these functions to calculate total event suspended concentrations, we determined that the buffer reduced suspended sediment concentration by 34 to 87%, for the range of events monitored. Removal of sediment from runoff generated on a 2.4‐m‐wide, 165‐m‐long unpaved road section was achieved principally via ponding, which reduced the transport capacity as flow entered the relatively flat, saturated buffer. Sediment deposition occurred primarily within the first 10 m of the buffer. Some sediment was also deposited on the fillslope leading to the buffer. Maximum road sediment concentration during the largest buffer event approached 100 000 mg L−1 Meanwhile, the corresponding maximum stream suspended sediment concentration was <4000 mg L−1 In contrast, maximum stream concentrations when flow bypassed the buffer during smaller events were commonly 4000 to 7000 mg L−1 Naturally occurring buffers represent an economical means of mitigating road‐related impacts in upland basins in Southeast Asia, particularly if combined with measures limiting sediment and runoff production on contributing road sections.
Occurrence of Arsenic in Ground Water in the Choushui River Alluvial Fan, Taiwan
Authors: Liu Chen‐Wuing , Wang Sheng‐Wei , Jang Cheng‐Shin , Lin Kao‐Hong
Published: January 2006

An investigation of shallow ground water quality revealed that high arsenic (As) concentrations were found in both aquifers and aquitards in the southern Choushui River alluvial fan of Taiwan. A total of 655 geological core samples from 13 drilling wells were collected and analyzed. High As contents were found primarily in aquitards, to a maximum of 590 mg/kg. The contents were correlated with the locations of the marine sequences. Additionally, strong correlations among the As concentrations of core samples, the clay, and the geological age of the Holocene transgression were identified. Most of the As in ground water originated from the aquitard of the marine sequence. The high As content in marine formations with high clay contents may be attributable to the bioaccumulation of As in the sea organisms, which accrued and were deposited in the formation. A preliminary geogenic model of the origin of the high As concentration in the shallow sedimentary basin of the Choushui River alluvial fan of Taiwan is proposed.
Instrumentation for Measuring Runoff, Sediment, and Chemical Losses from Agricultural Fields
Authors: Bonilla Carlos A. , Kroll David G. , Norman John M. , Yoder Daniel C. , Molling Christine C. , Miller Paul S. , Panuska John C. , Topel Jeffrey B. , Wakeman Peter L. , Karthikeyan K. G.
Published: January 2006

This work describes a simple, passive sampling system for measuring runoff, sediment, and chemical losses from typical agricultural fields. The sampler consists of a 5 to 7 m wide runoff collector connected to a series of multislot divisors. These divisors split the flow into aliquots, providing a continuous sampling during the runoff event. Divisors were located in a wooden box below ground level. With an adequate pump, this system can operate in fields with a slope gradient as low as 2%, and can stay in the field during winter to record first snowmelt‐generated runoff. A radio transmitter reports by telemetry the occurrence and magnitude of any runoff event, and indicates when the system should be sampled and emptied. This article includes a description of the equipment, advantages, and disadvantages based on 2 yr of operation, and examples of data collected.
Phosphorus Sequestration by Chemical Amendments to Reduce Leaching from Wastewater Applications
Authors: Zvomuya Francis , Rosen Carl J. , Gupta Satish C.
Published: January 2006

Phosphorus‐immobilizing amendments can be useful in minimizing P leaching from high P soils that may be irrigated with wastewater. This study tested the P‐binding ability of various amendment materials in a laboratory incubation experiment and then tested the best amendment in a field setup using drainage lysimeters. The laboratory experiment involved incubating 100‐g samples of soil (72 mg kg−1 water‐extractable phosphorus, WEP) with various amendments at different rates for 63 d at field moisture capacity and 25°C. The amendments tested were alum [Al2(SO4)3·14H2O], ferric chloride (FeCl3), calcium carbonate (CaCO3), water treatment residual (WTR), and sugarbeet lime (SBL). Ferric chloride and alum at rates of 1.5 and 3.9 g kg−1, respectively, were the most effective amendments that decreased WEP to 20 mg kg−1, below which leaching has previously been shown to be low. Alum (1.3 kg m−2), which is less sensitive to redox conditions, was subsequently tested under field conditions, where it reduced WEP concentration in the 0‐ to 0.15‐m layer from 119 mg kg−1 on Day 0 to 36.1 mg kg−1 (85% decrease) on Day 41. Lysimeter breakthrough tests using tertiary‐treated potato‐processing wastewater (mean total phosphorus [TP] = 3.4 mg L−1) showed that alum application reduced leachate TP and soluble reactive phosphorus (SRP) concentrations by 27 and 25%, respectively. These results indicate that alum application may be an effective strategy to immobilize P in high P coarse‐textured soils. The relatively smaller decreases in TP and SRP in the leachate compared to WEP suggest some of the P may be coming from depths below 0.2 m. Thus, to achieve higher P sequestration, deeper incorporation of the alum may be necessary.
Temporal and Spatial Distributions of Sediment Total Organic Carbon in an Estuary River
Authors: Ouyang Y. , Zhang J. E. , Ou L.‐T.
Published: January 2006

Understanding temporal and spatial distributions of naturally occurring total organic carbon (TOC) in sediments is critical because TOC is an important feature of surface water quality. This study investigated temporal and spatial distributions of sediment TOC and its relationships to sediment contaminants in the Cedar and Ortega Rivers, Florida, USA, using three‐dimensional kriging analysis and field measurement. Analysis of field data showed that large temporal changes in sediment TOC concentrations occurred in the rivers, which reflected changes in the characteristics and magnitude of inputs into the rivers during approximately the last 100 yr. The average concentration of TOC in sediments from the Cedar and Ortega Rivers was 12.7% with a maximum of 22.6% and a minimum of 2.3%. In general, more TOC accumulated at the upper 1.0 m of the sediment in the southern part of the Ortega River although the TOC sedimentation varied with locations and depths. In contrast, high concentrations of sediment contaminants, that is, total polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), were found in sediments from the Cedar River. There was no correlation between TOC and PAHs or PCBs in these river sediments. This finding is in contradiction to some other studies which reported that the sorption of hydrocarbons is highly related to the organic matter content of sediments. This discrepancy occurred because of the differences in TOC and hydrocarbon source input locations. It was found that more TOC loaded into the southern part of the Ortega River, while almost all of the hydrocarbons entered into the Cedar River. This study suggested that the locations of their input sources as well as the land use patterns should also be considered when relating hydrocarbons to sediment TOC.
An Approach for Measuring Methane Emissions from Whole Farms
Authors: McGinn S. M. , Flesch T. K. , Harper L. A. , Beauchemin K. A.
Published: January 2006

Estimates of enteric methane (CH4) emissions from ruminants are typically measured by confining animals in large chambers, using head hoods or masks, or by a ratiometric technique involving sampling respired air of the animal. These techniques are not appropriate to evaluate large‐scale farm emissions and the variability between farms that may be partly attributed to different farm management. This study describes the application of an inverse‐dispersion technique to calculate farm emissions in a controlled tracer‐release experiment. Our study was conducted at a commercial dairy farm in southern Alberta, Canada (total of 321 cattle, including 152 lactating dairy cows). Sulfur hexafluoride (SF6) and CH4 were released from 10 outlet locations (barn and open pens) using mass‐flow controllers. A Lagrangian stochastic (LS) dispersion model was then used to infer farm emissions from downwind gas concentrations. Concentrations of SF6 and CH4 were measured by gas chromatography analysis and open path lasers, respectively. Wind statistics were measured with a three‐dimensional sonic anemometer. Comparing the inferred emissions with the known release rate showed we recovered 86% of the released CH4 and 100% of the released SF6 The location of the concentration observations downwind of the farm was critically important to the success of this technique.
Reconceptualizing Play: Aesthetic Self-Definitions
Authors: Guss Faith
Published: January 2006

This article aims to trouble the identity of children's dramatic play(ing). It contains two interweaving threads of discourse. In one thread lies a discussion of how children can trouble and extend their own identities through the aesthetic form-languages and conventions they employ and deploy in their dramatic playing/pretend playing. Whereas adults exchange thoughts verbally, children enter the play-arena and converse and reflect with, and in, dramatic form-languages. In dramatic form, through taking the perspective of, and momentarily becoming, The Other, the children problematize and construct temporary identities. In each dramatic enactment they are in a reflective process of becoming. In the second thread of discourse, the article troubles the theoretical identity of dramatic playing — as it is perceived in the dominant play theory of sociology, which defines playing as reproduction. This issue is addressed through the aesthetic concept of mimesis, by which playing is defined as critical transformation. In the interpretative work the author shows how, in the privacy of the children's play-culture, they have the cultural occasion, space, and liberty to take control: to question, to speak for themselves, to represent, transform and define themselves. The players can experiment with standpoints, redefine their identities and, thereby, take back their power of self-definition. Cultural hegemony can be turned on its head.
Identity and Power, ‘Meaning’, Gender and Age: Children's Creative Work as a Signifying Practice
Authors: Lind Ulla
Published: January 2006

This article presents a negotiating practice that demonstrates the importance of the interplay of visual, verbal and linguistic signs. As such it discusses the relationship between identity and a signifying practice in a Swedish preschool, as children and teachers negotiate meaning. With emphasis on the relationship between building identity and having access to discourses, the notion of identity is troubled among these children, the teachers and within the research practice. A negotiating practice unfolds thanks to a documentation practice that also forms the research material: photographs and conversations made and used within the children's work in a seven month-long creative process.
Water‐in‐oil emulsion foaming by thiourea nitrosation: Reaction and mass transfer
Authors: da Silva Gabriel , Dlugogorski Bogdan Z. , Kennedy Eric M.
Published: January 2006

A study has been undertaken into the chemical production of gas bubbles within a concentrated water‐in‐oil emulsion, typical of those used as emulsion explosives. Chemical foaming was initiated by the introduction of a concentrated sodium nitrite solution to the emulsion, and the measurement of the decreasing emulsion density with time served to estimate the rate of nitrogen production. A conversion of emulsion density to nitrite ion concentration facilitated a kinetic analysis of the data. The change in nitrite ion concentration follows a rate equation which indicates that the rate‐limiting reaction step corresponds to the N‐nitrosation of thiourea by ON+, with an apparent rate constant of 0.22 M−1 s−1 at 25 °C. Tests over a temperature range of 25 to 50 °C yielded an activation energy of 59 kJ mol−1. A mass‐transfer model describing the rate of diffusion between aqueous droplets is presented. This model suggests that chemical kinetics, rather than molecular diffusion, is the rate‐limiting phenomenon in the foaming of emulsions. Supporting this finding, the kinetic experiments in emulsion returned very similar results to previous experiments performed in aqueous media under similar conditions. © 2006 American Institute of Chemical Engineers AIChE J, 2006
Agent distribution and water remaining of polyester nonwoven fabrics after‐treated with polyurethane–citric acid
Authors: Wang Chang
Published: January 2006

Polyester nonwoven fabric samples were used to treat with aqueous solutions of water‐soluble polyurethane (PU) containing the foaming agent, citric acid, or the mixtures of foaming agent and citric acid to examine the water remaining and the degradation of PU under the simulative condition of under ground. The results reveal that the viscosity of PU solutions could affect the values of pickup and add‐on. The water remaining values for PU containing citric acid are higher than those for PU containing the foaming agent and PU containing the foaming agent and citric acid. The pore structures, nonwoven construction, and the pores caused by the aggregation of PU within/on the treated nonwoven fabrics can affect the water remaining. From the observation of SEM and the comparison of FTIR, the degradation of water‐soluble PU resin is proved, which could form the rough porous surface of PU resin on the fiber surface as a factor improving the water remaining. The value of water remaining for PU containing citric after 60 weeks' treatment is significantly higher than the pristine nonwoven fabric (control). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 47–56, 2006
New technologies, new findings, and new concepts in the study of vertebrate cis‐regulatory sequences
Authors: Gómez‐Skarmeta José Luis , Lenhard Boris , Becker Thomas S.
Published: January 2006

All vertebrates share a similar early embryonic body plan and use the same regulatory genes for their development. The availability of numerous sequenced vertebrate genomes and significant advances in bioinformatics have resulted in the finding that the genomic regions of many of these developmental regulatory genes also contain highly conserved noncoding sequence. In silico discovery of conserved noncoding regions and of transcription factor binding sites as well as the development of methods for high throughput transgenesis in Xenopus and zebrafish are dramatically increasing the speed with which regulatory elements can be discovered, characterized, and tested in the context of whole live embryos. We review here some of the recent technological developments that will likely lead to a surge in research on how vertebrate genomes encode regulation of transcriptional activity, how regulatory sequences constrain genomic architecture, and ultimately how vertebrate form has evolved. Developmental Dynamics 235:870–885, 2006. © 2006 Wiley‐Liss, Inc.
Spatial relations between avian craniofacial neural crest and paraxial mesoderm cells
Authors: Evans Darrell J.R. , Noden Drew M.
Published: January 2006

Fate maps based on quail–chick grafting of avian cephalic neural crest precursors and paraxial mesoderm cells have identified the majority of derivatives from each population but have not unequivocally resolved the precise locations of and population dynamics at the interface between them. The relation between these two mesenchymal tissues is especially critical for the development of skeletal muscles, because crest cells play an essential role in their differentiation and subsequent spatial organization. It is not known whether myogenic mesoderm and skeletogenic neural crest cells establish permanent relations while en route to their final destinations, or later at the sites where musculoskeletal morphogenesis is completed. We applied β‐galactosidase‐encoding, replication‐incompetent retroviruses to paraxial mesoderm, to crest progenitors, or at the interface between mesodermal and overlying neural crest as both were en route to branchial or periocular regions in chick embryos. With respect to skeletal structures, the results identify the avian neural crest:mesoderm boundary at the junction of the supraorbital and calvarial regions of the frontal bone, lateral to the hypophyseal foramen, and rostral to laryngeal cartilages. Therefore, in the chick embryo, most of the frontal and the entire parietal bone are of mesodermal, not neural crest, origin. Within paraxial mesoderm, the progenitors of each lineage display different behaviors. Chondrogenic cells are relatively stationary and intramembranous osteogenic cells move only in transverse planes around the brain. Angioblasts migrate invasively in all directions. Extraocular muscle precursors form tightly aggregated masses that en masse cross the crest:mesoderm interface to enter periocular territories, while branchial myogenic lineages shift ventrally coincidental with the movements of corresponding neural crest cells. En route to the branchial arches, myogenic mesoderm cells do not maintain constant, nearest‐neighbor relations with adjacent, overlying neural crest cells. Thus, progenitors of individual muscles do not establish stable, permanent relations with their connective tissues until both populations reach the sites of their morphogenesis within branchial arches or orbital regions. Developmental Dynamics 235:1310–1325, 2006. © 2006 Wiley‐Liss, Inc.
Sister chromatid exchange analysis in smelting plant workers exposed to arsenic
Authors: Paiva Leiliane , Martínez Valeria , Creus Amadeu , Quinteros Domingo , Marcos Ricardo
Published: January 2006

There are many studies documenting the genotoxic effects of environmental exposure to arsenic. Nevertheless, few data are available on the genotoxic risks of occupational arsenic exposure. In the present study, we have evaluated whether or not occupational exposure to arsenic in a copper smelting plant results in a significant increase in the frequency of sister chromatid exchange (SCE). SCE frequencies, proliferation rate index (PRI), and high frequency cells (HFCs) were evaluated in peripheral blood lymphocytes from a group of 105 arsenic‐exposed workers from a Chilean smelting plant (exposed group). Similar assays were conducted on a group of 55 workers employed at the same mine but involved in administrative jobs (internal control), and on 48 workers of another mine, with no significant levels of arsenic (external control). Small but significant increases in SCE frequency were observed in the arsenic‐exposed workers compared with the external control group (6.28 ± 0.09 vs. 5.84 ± 0.14 SCE/cell; P < 0.01). Also, significantly higher frequencies of HFCs were observed in the exposed group (2.21% ± 0.20%) than in either the external control group (1.20 ± 0.23; P = 0.002) or the internal control group (1.30 ± 0.24; P = 0.008). However, there was no relationship between arsenic levels in the urine of the subjects and SCE or HFC frequency. The results of the study indicate that copper smelting results in slightly increased levels of DNA damage. However, our data were not consistent with arsenic exposure being the cause of the increase. Environ. Mol. Mutagen., 2006. © 2006 Wiley‐Liss, Inc.
Mechanisms of genotoxicity of nucleoside reverse transcriptase inhibitors
Authors: Olivero Ofelia A.
Published: January 2006

Nucleoside analogs were first approved by the U.S. Food and Drug Administration for use against HIV‐AIDS in 1987. Since then, these agents, now commonly referred to as nucleoside reverse transcriptase inhibitors (NRTIs), have become essential components of the Highly Active Antiretroviral Therapy (HAART) drug combinations used for treatment of Human Immunodeficiency Virus‐1 (HIV‐1) infections. Their antiretroviral activity is likely two‐fold: incorporation of the drug into viral DNA and inhibition of the viral reverse transcriptase. However, incorporation of the drug into host nuclear and mitochondrial DNA may be largely responsible for dose‐limiting toxicities. Azidothymidine (AZT, 3′‐azido‐3′‐deoxythymidine, zidovudine), the first NRTI approved for the therapy of HIV‐1, is incorporated into DNA, causes mutations in the hypoxanthine‐guanine phosphoribosyl‐transferase (HPRT) and thymidine kinase (TK) genes, and induces micronuclei, chromosomal aberrations, sister chromatid exchange, shortened telomeres, and other genotoxic effects in cultured cells. Genomic instability would be predicted as a consequence of these events. Metabolic pathways that result in the phosphorylation of AZT play a crucial role in AZT‐DNA incorporation, and may be altered after prolonged treatment. For example, thymidine kinase 1, the enzyme responsible for AZT mono‐phosphorylation, is down‐regulated during long‐term exposure and appears to be associated with AZT‐induced replication inhibition and the accumulation of cells in S‐phase. Detailed information on the mechanisms underlying NRTI‐associated antiretroviral efficacy, toxicity, and metabolic resistance were not available when AZT was first approved for use as an antiretroviral agent. Current insights, based on 15 years of research, may lead to intervention strategies to attenuate toxicity without altering drug efficacy. Environ. Mol. Mutagen., 2006. Published 2006 Wiley‐Liss, Inc.
Real‐time detection of epidermal growth factor receptor expression in fresh oral cavity biopsies using a molecular‐specific contrast agent
Authors: Hsu Elizabeth R. , Gillenwater Ann M. , Hasan M. Qasim , Williams Michelle D. , El‐Naggar Adel K. , Richards‐Kortum Rebecca R.
Published: January 2006

Early diagnosis of individuals with high risk of developing head and neck squamous carcinoma should lead to decreased morbidity and increased survival. To aid in noninvasive early detection of oral neoplasia in vivo, we have developed a molecular‐specific fluorescent contrast agent, consisting of a far‐red fluorescent dye coupled to a monoclonal antibody targeted against the epidermal growth factor receptor. In our study, we used organ cultures of normal and neoplastic human oral tissue to evaluate the capabilities of using this contrast agent to enhance clinical diagnosis. Fresh tissue sections were prepared from 34 biopsies of clinically normal and abnormal oral mucosa from 17 consenting patients. Samples were exposed to contrast agent, rinsed and the presence of bound agent was detected using fluorescence confocal microscopy. Simple assays to assess cytotoxicity of the dye used in the agent and to determine labeling efficacy at physiologic temperatures were also performed. Results indicate that the mean fluorescence intensity (MFI) of samples with dysplasia and cancer are higher than that of the normal sample from the same patient, and that this increase in fluorescence could potentially be used in the early detection and delineation of premalignant lesions. Normal tissue could be distinguished from cancer or moderate dysplasia, using either the ratio of the MFI of abnormal to normal tissue or the MFI obtained from the epithelial surface. No detrimental effects from the dye were observed over a 4‐day period. These results indicate that the use of this optical contrast agent could yield important clinical advantages for noninvasive early detection and molecular characterization of oral mucosa. © 2006 Wiley‐Liss, Inc.
Clinical significance of mannose‐binding lectin‐associated serine protease‐2 expression in esophageal squamous cell carcinoma
Authors: Verma Amit , Matta Ajay , Shukla Nootan Kumar , Deo Suryanarayana V.S. , Gupta Siddarth Datta , Ralhan Ranju
Published: January 2006

Mannan‐binding lectin‐associated serine protease‐2 (MASP‐2) is a serine protease involved in the activation of lectin complement pathway. The differential expression of MASP‐2 in human esophageal squamous cell carcinoma (ESCC) was recently reported from our laboratory using differential display. To determine the expression of MASP‐2 protein, we raised a polyclonal antibody to human MASP‐2 and used it for immunohistochemical analysis of MASP‐2 in ESCCs. The antibody showed a single band of predicted molecular weight by western blotting. In normal human liver tissue, the cytoplasm was distinctly labeled by the antibody. Intriguingly, besides the cytoplasm, the nuclei of esophageal tumor cells were also labeled. To investigate the association of MASP‐2 expression with esophageal tumorigenesis, its expression was analyzed in 51 primary ESCCs, 32 dysplasias, 21 histologically normal esophageal tissues and 6 adenocarcinomas by immunohistochemistry. Increased MASP‐2 expression was observed in ESCCs (p = 0.001, Odd's ratio (OR) = 3.662) and in premalignant condition, dysplasia (p = 0.000, OR = 5.091) in comparison with the normal tissues. MASP‐2 expression in ESCCs was associated with late clinical stage (p = 0.009, O.R. = 3.430) and nodal metastasis (p = 0.001, O.R. = 4.520). In conclusion, our antibody was demonstrated to be useful in recognizing MASP‐2 expression on paraffin embedded tissue sections. To our knowledge, this is the first report showing MASP‐2 expression in a solid tumor. MASP‐2 expression in premalignant stage (dysplasia) as well as in ESCCs and its association with late clinical stage and nodal metastasis suggest that alteration in its expression is maintained during disease progression and is associated with aggressive tumor behavior. © 2006 Wiley‐Liss, Inc.
Cooperative antitumor effects of vitamin D3 derivatives and rosemary preparations in a mouse model of myeloid leukemia
Authors: Sharabani Hagar , Izumchenko Eugene , Wang Qing , Kreinin Rita , Steiner Michael , Barvish Zeev , Kafka Michael , Sharoni Yoav , Levy Joseph , Uskokovic Milan , Studzinski George P. , Danilenko Michael
Published: January 2006

1α,25‐dihydroxyvitamin D3 (1,25D3) is a powerful differentiation agent, which has potential for treatment of myeloid leukemias and other types of cancer, but the calcemia produced by pharmacologically active doses precludes the use of this agent in the clinic. We have shown that carnosic acid, the major rosemary polyphenol, enhances the differentiating and antiproliferative effects of low concentrations of 1,25D3 in human myeloid leukemia cell lines (HL60, U937). Here we translated these findings to in vivo conditions using a syngeneic mouse leukemia tumor model. To this end, we first demonstrated that as in HL60 cells, differentiation of WEHI‐3B D− murine myelomonocytic leukemia cells induced by 1 nM 1,25D3 or its low‐calcemic analog, 1,25‐dihydroxy‐16‐ene‐5,6‐trans‐cholecalciferol (Ro25‐4020), can be synergistically potentiated by carnosic acid (10 μM) or the carnosic acid‐rich ethanolic extract of rosemary leaves. This effect was accompanied by cell cycle arrest in G0+G1 phase and a marked inhibition of cell growth. In the in vivo studies, i.p. injections of 2 μg Ro25‐4020 in Balb/c mice bearing WEHI‐3B D− tumors produced a significant delay in tumor appearance and reduction in tumor size, without significant toxicity. Another analog, 1,25‐dihydroxy‐16,23Z‐diene‐20‐epi‐26,27‐hexafluoro‐19‐nor‐cholecalciferol (Ro26‐3884) administered at the same dose was less effective than Ro25‐4020 and profoundly toxic. Importantly, combined treatment with 1% dry rosemary extract (mixed with food) and 1 μg Ro25‐4020 resulted in a strong cooperative antitumor effect, without inducing hypercalcemia. These results indicate for the first time that a plant polyphenolic preparation and a vitamin D derivative can cooperate not only in inducing leukemia cell differentiation in vitro, but also in the antileukemic activity in vivo. These data may suggest novel protocols for chemoprevention or differentiation therapy of myeloid leukemia. © 2006 Wiley‐Liss, Inc.
Loss of RAB25 expression in breast cancer
Authors: Cheng Ji‐Ming , Ding Ming , Aribi Ahmed , Shah Prabodh , Rao Krishna
Published: January 2006

A novel breast cancer cell line (RAO‐3) was established by transduction of the Q61L mutant RAS into human mammary epithelial cells that were immortalized with catalytic subunit of telomerase (hTERT). The cells displayed anchorage‐independent growth and proliferation, and formed human mammary spindle cell carcinoma when injected into nude mice. Chromosome locus 1q22‐23 was partially duplicated and inverted on one of the 3 chromosomes present in the cell line. We report here that mutations of chromosome 1q22‐23 locus have resulted in the loss of RAB25 expression in the breast cancer cell line. Transduction of RAB25 into the breast cancer cell line arrests anchorage‐independent growth. We have also demonstrated loss of RAB25 in human breast tumor tissue. These data suggest that loss of RAB25 might contribute to tumorigenesis of breast cancer, and RAB25 is likely to be an important factor in the development of breast cancer. RAB25 could be used as biological marker of breast cancer and provides a target for gene replacement therapy. © 2006 Wiley‐Liss, Inc.
Use of hormone therapy and risk of breast cancer detected at screening and between mammographic screens
Authors: Hofvind Solveig , Møller Bjørn , Thoresen Steinar , Ursin Giske
Published: January 2006

Postmenopausal hormone therapy (HT) is associated with increased risk of breast cancer, but in women undergoing breast cancer screening it is not clear whether use of HT is associated with increased risk of breast cancer detected at screening or between screens (interval cancer). Further, it is unclear whether the use of the HTs that have been common in Scandinavia is associated with higher risk of breast cancer than the HTs used in other countries. Our study was based on data from 296,651 women aged 50–69 years, who participated in the Norwegian Breast Cancer Screening Program during 1995–2004. After a mean enrollment time of 3.8 years, 1,512 women were diagnosed with invasive screen detected breast cancer, and 814 with invasive interval breast cancer. Cox regression models were used to estimate hazard ratios (HRs) of breast cancer associated with HT use, after adjusting for confounders. Ever users of HT had a 58% increased risk of breast cancer, compared to never users. The HRs associated with HT use were 1.45 (95% confidence interval (CI) = 1.29–1.63) for screen detected and 1.89 (95% CI = 1.61–2.23) for interval cancer. The difference between screen detected and interval cancer was statistically significant (p = 0.011). The HR of breast cancer increased with duration of HT use, but significantly more so for interval than for screen detected cancer (use of HT for 5 or more years compared to never use; HR = 2.91, 95% CI = 2.10–4.04 and HR = 1.94, 95% CI = 1.51–2.50, respectively; p = 0.002). The population attributable fraction of breast cancer due to HT use was 19.8% overall. Ever users of HT tended to develop a cancer of lower grade. No other differences in histological tumor characteristics were observed between ever and never users of HT among screen detected or interval cancers. The estimated risks of either breast cancer overall with HT use are higher in Norway than reported in similar studies from the U.S. HT‐use is a stronger risk factor for interval cancer than for screen detected cancer. The increased risk of interval cancer, which may partly be due to decreased sensitivity of mammograms in HT users, remains a challenge in breast cancer screening programs. © 2006 Wiley‐Liss, Inc.
Tea drinking and the risk of biliary tract cancers and biliary stones: A population‐based case–control study in Shanghai, China
Authors: Zhang Xue‐Hong , Andreotti Gabriella , Gao Yu‐Tang , Deng Jie , Liu Enju , Rashid Asif , Wu Kai , Sun Lu , Sakoda Lori C. , Cheng Jia‐Rong , Shen Ming‐Chang , Wang Bing‐Sheng , Han Tian‐Quan , Zhang Bai‐He , Gridley Gloria , Fraumeni Joseph F. , Hsing Ann W.
Published: January 2006

Biliary tract cancers, encompassing tumors of the gallbladder, extrahepatic bile ducts and ampulla of Vater, are rare but highly fatal malignancies. Apart from gallstones, etiologic factors for biliary tract cancer are not clearly defined. Several epidemiologic studies have suggested that consumption of tea, especially green tea, is protective against a variety of cancers, including gastrointestinal malignancies. As part of a large population‐based case–control study of biliary tract disease in Shanghai, China, we evaluated the effects of tea consumption on the risk of biliary tract cancers and biliary stones. The study included 627 incident cases with biliary tract cancer, 1,037 cases with biliary stones and 959 randomly selected controls. Study subjects were interviewed to ascertain data on demographic, medical and dietary factors, including tea consumption. Forty‐one percent of the controls were ever tea drinkers, defined as those who consumed at least 1 cup of tea per day for at least 6 months. After adjustment for age, education and body mass index, among women, ever tea drinkers had significantly reduced risks of biliary stones (OR = 0.73, 95% CI = 0.54–0.98) and gallbladder cancer (OR = 0.56, 95% CI = 0.38–0.83). The inverse relationship between tea consumption and gallbladder cancer risk was independent of gallstone disease. Among men, tea drinkers were more likely to be cigarette smokers, and the risk estimates were generally below 1.0, but were not statistically significant. Further studies are needed to confirm these results in other populations and clarify the hormonal and other mechanisms that may be involved. © 2006 Wiley‐Liss, Inc.
An overview of the association between allergy and cancer
Authors: Turner Michelle C. , Chen Yue , Krewski Daniel , Ghadirian Parviz
Published: January 2006

Numerous epidemiological studies have evaluated some aspect of the association between a history of allergy and cancer occurrence. In this article, an overview of the epidemiological evidence is presented with a discussion of a number of methodological issues important in this area of study. Literature searches were conducted using the MEDLINE database from 1966 through to August 2005 to identify articles that explored a personal history of allergic disorders as a risk factor for cancer. Although it is difficult to draw conclusions between allergy and cancer at many sites because of insufficient evidence or a lack of consistency both within and among studies completed to date, strong inverse associations have been reported for pancreatic cancer and glioma, whereas lung cancer was positively associated with asthma. Additional studies are needed to confirm these finding and to address the limitations of previous studies, including the validity and reliability of exposure measures and control for confounding. Further, large prospective studies using cancer incidence would be particularly useful, including studies using biological markers of allergic status to reduce potential misclassification and to confirm the results of previous studies based on self‐report. There is also a need for further basic research to clarify a potential mechanism, should an association exist. © 2006 Wiley‐Liss, Inc.
Asthma history, occupational exposure to pesticides and the risk of non‐Hodgkin's lymphoma
Authors: Lee Won Jin , Purdue Mark P. , Stewart Patricia , Schenk Maryjean , De Roos Anneclaire J. , Cerhan James R. , Severson Richard K. , Cozen Wendy , Hartge Patricia , Blair Aaron
Published: January 2006

We previously reported that, although asthma did not increase the risk of non‐Hodgkin's lymphoma (NHL), the risk from pesticide exposures was higher among asthmatics than that among nonasthmatics. To further evaluate this finding, we analyzed data from a population‐based case–control study of NHL conducted in Iowa, Detroit, Los Angeles and Seattle. Cases (n = 668) diagnosed with NHL from 1998 to 2000 and controls (n = 543) randomly selected from the same geographical areas as that of the cases were included in this analysis. Odds ratios (OR) for the risk of NHL from potential occupational exposure to pesticides tended to be higher among asthmatics (OR = 1.7; 95% CI 0.3–9.1) when compared with that among nonasthmatics (OR = 0.9; 95% CI 0.6–1.5). The risks of NHL associated with pesticide exposure were also higher among asthmatics who had history of hospitalization (OR = 2.1; 95% CI 0.2–29.0) or daily medication for asthma (OR = infinite) than those among asthmatics who did not have such histories. Our results support the previous finding that the risk of NHL from pesticide exposure may be greater among asthmatics. © 2006 Wiley‐Liss, Inc.
Role of Rac1 and Cdc42 in hypoxia induced p53 and von Hippel‐Lindau suppression and HIF1α activation
Authors: Xue Yan , Bi Feng , Zhang Xueyong , Zhang Siyuan , Pan Yanglin , Liu Na , Shi Yongquan , Yao Xuebiao , Zheng Yi , Fan Daiming
Published: January 2006

Low oxygen tension can influence tumor progression by enhancing angiogenesis, a process that may involve Rho GTPases whose activities have been implicated in tumorigenesis and metastasis. In the present study, we show that hypoxia can increase the mRNA levels and intracellular activities of Rac1 and Cdc42 in a time‐dependent manner. The hypoxia‐stimulated activities of Rac1 and Cdc42 could be blocked by the phosphatidylinositol 3′‐kinase (PI3K) inhibitor LY294002 and the protein tyrosine kinase (PTK) inhibitor genistein but were not affected by the p38MAPK inhibitor SB203580 or the MEK‐1 inhibitor PD98059, suggesting that the hypoxia‐mediated signals were through PI3K and PTK. Correlating with the increased activities of Rac1 and Cdc42, the expression of the pro‐angiogenesis factors HIF‐1α and vascular endothelial growth factor (VEGF) was upregulated by hypoxia, whereas the expression of the tumor suppressors von Hippel‐Lindau and p53 was down‐regulated. Dominant negative N17Rac1 and N17Cdc42 could upregulate the expression of p53 and pVHL but downregulate that of HIF‐1α and VEGF under hypoxia. Furthermore, the preconditioned medium from N17Rac1 or N17Cdc42‐expressing gastric cancer cells was able to inhibit the proliferation of HUVECs. Our results indicate that PI3K and PTK‐mediated activations of Rac1 and Cdc42 are involved in the hypoxia‐induced production of angiogenesis‐promoting factors and tumor suppressors, and suggest that the Rho family GTPases Rac1 and Cdc42 may contribute to the hypoxia‐mediated angiogenesis. © 2006 Wiley‐Liss, Inc.
Inhibition of antitumor immunity by invariant natural killer T cells in a T‐cell lymphoma model in vivo
Authors: Renukaradhya Gourapura J. , Sriram Venkataraman , Du Wenjun , Gervay‐Hague Jacquelyn , Van Kaer Luc , Brutkiewicz Randy R.
Published: January 2006

We have investigated the role of the host's CD1d‐dependent innate antitumor immune response in a murine T‐cell lymphoma model in vivo. We found that C57BL/6 wildtype (WT) mice inoculated with RMA/S cells transfected with murine CD1d1 died at the same rate as mice inoculated with vector‐transfected cells. In contrast, natural killer T (NKT) cell‐deficient CD1d or Jα18 knockout mice inoculated with CD1d‐transfected RMA/S cells survived significantly longer than mice inoculated with vector‐transfected RMA/S cells, implicating the involvement of invariant NKT (iNKT) cells in inhibiting antitumor activity in vivo. In contrast to the mutant mice, which produced more of the proinflammatory cytokines IFN‐γ and GM‐CSF, WT mice produced significantly elevated amounts of IL‐13. Antitumor activity in the knockout mice was not due to the development of CD1d‐specific cytotoxic T lymphocytes or circulating antibodies. However, iNKT cell numbers were elevated in tumor‐bearing mice. Thus, iNKT cells may be playing a negative role in the host's antitumor immune response against T‐cell lymphomas in a CD1d‐dependent manner. © 2006 Wiley‐Liss, Inc.
p38 MAPK turns hepatocyte growth factor to a death signal that commits ovarian cancer cells to chemotherapy‐induced apoptosis
Authors: Coltella Nadia , Rasola Andrea , Nano Elisa , Bardella Chiara , Fassetta Michela , Filigheddu Nicoletta , Graziani Andrea , Comoglio Paolo M. , Di Renzo Maria Flavia
Published: January 2006

We recently showed that Hepatocyte Growth Factor (HGF), known as a survival factor, unexpectedly enhances apoptosis in human ovarian cancer cells treated with the front‐line chemotherapeutics cisplatin (CDDP) and paclitaxel (PTX). Here we demonstrate that this effect depends on the p38 mitogen‐activated kinase (MAPK). In fact, p38 MAPK activity is stimulated by HGF and further increased by the combined treatment with HGF and either CDDP or PTX. The expression of a dominant negative form of p38 MAPK abrogates apoptosis elicited by drugs, alone or in combination with HGF. HGF and drugs also activate the ERK1/2 MAPKs, the PI3K/AKT and the AKT substrate mTOR. However, activation of these survival pathways does not hinder the ability of HGF to enhance drug‐dependent apoptosis. Altogether data show that p38 MAPK is necessary for HGF sensitization of ovarian cancer cells to low‐doses of CDDP and PTX and might be sufficient to overcome activation of survival pathways. Therefore, the p38 MAPK pathway might be a suitable target to improve response to conventional chemotherapy in human ovarian cancer. © 2006 Wiley‐Liss, Inc.
Frequency permutation arrays
Authors: Huczynska Sophie , Mullen Gary L.
Published: January 2006

Motivated by recent interest in permutation arrays, we introduce and investigate the more general concept of frequency permutation arrays (FPAs). An FPA of lengthn = mλ and distancedis a setTof multipermutations on a multiset ofmsymbols, each repeated with frequency λ, such that the Hamming distance between any distinctx,y∈Tis at leastd. Such arrays have potential applications in powerline communication. In this article, we establish basic properties of FPAs, and provide direct constructions for FPAs using a range of combinatorial objects, including polynomials over finite fields, combinatorial designs, and codes. We also provide recursive constructions, and give bounds for the maximum size of such arrays. © 2006 Wiley Periodicals, Inc. J Combin Designs 14: 463–478, 2006
Skin responses to fractional photothermolysis
Authors: Laubach Hans‐Joachim , Tannous Zeina , Anderson R. Rox , Manstein Dieter
Published: January 2006

Background and Objective

Fractional photothermolysis (FP) is a new concept using arrays of microscopic thermal damage patterns to stimulate a therapeutic response. We analyzed epidermal and dermal response to FP with the aim of correlating histological and clinical response.

Study Design/Materials and Methods

Twelve subjects received a single treatment with a prototype diode laser emitting at a wavelength of 1,500 nm, delivering 5 mJ per microscopic treatment zone (MTZ), and a density of 1,600 MTZs/cm2 on the forearm. Biopsies were procured over a period of 3 months. The biopsies were analyzed by two blinded dermatopathologists using hematoxylin and eosin (Hematoxylin and Eosin Stain), Elastica von Gieson, nitro‐blue‐tetrazolium‐chloride (NBTC) viability, and immunohistochemistry stains. Furthermore, the treatment sites were evaluated in vivo by confocal microscopy.

Results and Discussion

Twenty‐four hours after fractional photothermolysis, the continuity of the epidermal basal cell layer is restored. Complete epidermal regeneration is obtained 7 days after the treatment. Microscopic epidermal necrotic debris (MENDs) are seen as early as 1 day after FP. MENDs contain melanin pigment, and are shed from the epidermis within 7 days. Evidence of increased collagen III production is shown with immunohistochemistry (IHC) staining 7 days after FP. IHC for heat shock protein 70 (HSP 70) shows the expression of HSP 1 day after FP, and IHC for alpha smooth muscle actin shows the presence of myofibroblasts 7 days after FP. These findings are concordant with the induction of a wound healing response by FP. There is no evidence of residual dermal fibrosis 3 months after treatment.

Conclusion

A single treatment with fractional photothermolysis induces a wound healing response in the dermis. A mechanism for the precise removal of epidermal melanin is described, in which MENDs act as a melanin shuttle. Lasers Surg. Med. 38:142–149, 2006. © 2006 Wiley‐Liss, Inc.
Photodynamic therapy using meso tetra hydroxy phenyl chlorin (mTHPC) in early prostate cancer
Authors: Moore C.M. , Nathan T.R. , Lees W.R. , Mosse C.A. , Freeman A. , Emberton M. , Bown S.G.
Published: January 2006

Background and Objectives

Prostate cancer is increasing in incidence, but current treatments including surgery and radiotherapy have significant side effects. This pilot study was designed to assess the potential of photodynamic therapy (PDT) using meso tetra hydroxy phenyl chlorin (mTHPC) for organ confined prostate cancer.

Study Design/Patients and Methods

Six men with organ confined prostate cancer were photosensitised with mTHPC (0.15 mg/kg). Between 2 and 5 days later, red light (652 nm) was delivered to areas of biopsy proven cancer via fibres inserted through transperineal needles (50–100 J per site).

Results

After 8 of 10 PDT sessions, the prostate specific antigen (PSA) fell by up to 67%. Early MRI scans showed oedema and patchy necrosis, which resolved over 2 months. Biopsies of treated areas revealed necrosis and fibrosis at 1–2 months.

Conclusions

PDT for primary prostate cancer appears safe and can reduce PSA levels. As this was a phase I study, no attempt was made to treat the whole prostate; this or targeted tumour ablation could be attempted in a phase II study with an increased number of fibres. This technique merits further investigation in early prostate cancer. Lasers Surg. Med. © 2005 Wiley‐Liss, Inc.