bluuebunny/crossref_metadata_2025 huggingface dataset:
Intra‐basin variability of snowmelt water balance calculations in a subarctic catchment
Authors: McCartney Stephen E. , Carey Sean K. , Pomeroy John W.
Published: February 2006

The intra‐basin variability of snowmelt and melt‐water runoff hydrology in an 8 km2 subarctic alpine tundra catchment was examined for the 2003 melt period. The catchment, Granger Creek, is within the Wolf Creek Research Basin, Yukon, which is typical of mountain subarctic landscapes in northwestern Canada. The study catchment was segmented into nine internally uniform zones termed hydrological response units (HRUs) based on their similar hydrological, physiographic, vegetation and soil properties. Snow accumulation exhibited significant variability among the HRUs, with greatest snow water equivalent in areas of tall shrub vegetation. Melt began first on southerly exposures and at lower elevations, yet average melt rates for the study period varied little among HRUs with the exception of those with steep aspects. In HRUs with capping organic soils, melt water first infiltrated this surface horizon, satisfying its storage capacity, and then percolated into the frozen mineral substrate. Infiltration and percolation into frozen mineral soils was restricted where melt occurred rapidly and organic soils were thin; in this case, melt‐water delivery rates exceeded the frozen mineral soil infiltration rate, resulting in high runoff rates. In contrast, where there were slower melt rates and thick organic soils, infiltration was unlimited and runoff was suppressed. The snow water equivalent had a large impact on runoff volume, as soil storage capacity was quickly surpassed in areas of deep snow, diverting the bulk of melt water laterally to the drainage network. A spatially distributed water balance indicated that the snowmelt freshet was primarily controlled by areas with tall shrub vegetation that accumulate large quantities of snow and by alpine areas with no capping organic soils. The intra‐basin water balance variability has important implications for modelling freshet in hydrological models. Copyright © 2006 John Wiley & Sons, Ltd.
Estimating the snow water equivalent on the Gatineau catchment using hierarchical Bayesian modelling
Authors: Seidou Ousmane , Fortin Vincent , St‐Hilaire André , Favre Anne‐Catherine , Adlouni Salaheddine El , Bobée Bernard
Published: February 2006

One of the most important parameters for spring runoff forecasting is the snow water equivalent on the watershed, often estimated by kriging using in situ measurements, and in some cases by remote sensing. It is known that kriging techniques provide little information on uncertainty, aside from the kriging variance. In this paper, two approaches using Bayesian hierarchical modelling are compared with ordinary kriging; Bayesian hierarchical modelling is a flexible and general statistical approach that uses observations and prior knowledge to make inferences on both unobserved data (snow water equivalent on the watershed where there is no measurements) and on the parameters (influence of the covariables, spatial interactions between the values of the process at various sites). The first approach models snow water equivalent as a Gaussian spatial process, for which the mean varies in space, and the other uses the theory of Markov random fields. Although kriging and the Bayesian models give similar point estimates, the latter provide more information on the distribution of the snow water equivalent. Furthermore, kriging may considerably underestimate interpolation error. Copyright © 2006 Environment Canada. Published by John Wiley & Sons, Ltd.
Comparison of local scale measured and modelled brightness temperatures and snow parameters from the CLPX 2003 by means of a dense medium radiative transfer theory model
Authors: Tedesco Marco , Kim Edward J. , Cline Don , Graf Tobias , Koike Toshio , Armstrong Richard , Brodzik Mary J. , Hardy Janet
Published: February 2006

Some 27 years of passive microwave satellite observations have demonstrated the value of remote sensing for cryospheric applications, albeit at regional to hemispheric scales due to the relatively large sensor footprints (e.g. ∼25 km × 25 km for the advanced microwave scanning radiometer). At the other extreme there is the primarily local‐scale in situ experience of the snow community. Until higher‐resolution sensors become available, understanding the effects of sub‐pixel heterogeneity and the downscaling of observations remains an important topic.

In order to provide a baseline for performing scaling studies and for future radiance‐based hydrological assimilation schemes, an evaluation of snowpack forward radiance modelling at the plot scale (least heterogeneous scale) is carried out. Snow microwave radiance models based on dense medium radiative transfer (DMRT) theory incorporate a high degree of physical fidelity, yet dense medium models are particularly sensitive to snowpack structural parameters such as grain size, density, and depth (parameters that may vary substantially within a snowpack). The DMRT performance is evaluated through the use of a fitting technique with respect to snow grain size, a hydrologically important parameter related to the total amount of melt water stored in a snowpack, snowpack metamorphism, vertical energy transport and melt dynamics, as well as various quantities useful in surface energy balance studies. All remaining snow input parameters to the model are derived from snow pit measurements. Model‐predicted radiances are evaluated using microwave brightness measurements collected during the NASA Cold Land Process Experiment (CLPX) by the University of Tokyo's Ground‐Based Microwave Radiometer‐7 (GBMR‐7) system at 18·7, 36·5, and 89 GHz, with incidence angles ranging from 30 to 70 °. The detailed CLPX microwave and snow data provide an excellent opportunity to gain insight into the strengths and weaknesses of this approach. Copyright © 2006 John Wiley & Sons, Ltd.
Evaluation of gridded snow water equivalent and satellite snow cover products for mountain basins in a hydrologic model
Authors: Dressler K. A. , Leavesley G. H. , Bales R. C. , Fassnacht S. R.
Published: February 2006

The USGS precipitation‐runoff modelling system (PRMS) hydrologic model was used to evaluate experimental, gridded, 1 km2 snow‐covered area (SCA) and snow water equivalent (SWE) products for two headwater basins within the Rio Grande (i.e. upper Rio Grande River basin) and Salt River (i.e. Black River basin) drainages in the southwestern USA. The SCA product was the fraction of each 1 km2 pixel covered by snow and was derived from NOAA advanced very high‐resolution radiometer imagery. The SWE product was developed by multiplying the SCA product by SWE estimates interpolated from National Resources Conservation Service snow telemetry point measurements for a 6 year period (1995‐2000). Measured SCA and SWE estimates were consistently lower than values estimated from temperature and precipitation within PRMS. The greatest differences occurred in the relatively complex terrain of the Rio Grande basin, as opposed to the relatively homogeneous terrain of the Black River basin, where differences were small. Differences between modelled and measured snow were different for the accumulation period versus the ablation period and had an elevational trend. Assimilating the measured snowfields into a version of PRMS calibrated to achieve water balance without assimilation led to reduced performance in estimating streamflow for the Rio Grande and increased performance in estimating streamflow for the Black River basin. Correcting the measured SCA and SWE for canopy effects improved simulations by adding snow mostly in the mid‐to‐high elevations, where satellite estimates of SCA are lower than model estimates. Copyright © 2006 John Wiley & Sons, Ltd.
Recent trends in Canadian lake ice cover
Authors: Duguay Claude R. , Prowse Terry D. , Bonsal Barrie R. , Brown Ross D. , Lacroix Martin P. , Ménard Patrick
Published: February 2006

Recent studies have shown that ice duration in lakes and rivers over the Northern Hemisphere has decreased over the 19th and 20th centuries in response to global warming. However, lake ice trends have not been well documented in Canada. Because of its size, considerable variability may exist in both freeze‐up and break‐up dates across the country. In this paper, results of the analysis of recent trends (1951–2000) in freeze‐up and break‐up dates across Canada are presented. Trends toward earlier break‐up dates are observed for most lakes during the time periods of analysis which encompass the 1990s. Freeze‐up dates, on the other hand, show few significant trends and a low degree of temporal coherence when compared with break‐up dates. These results are compared with trends in autumn and spring 0 °C isotherm dates over the time period 1966–95. Similar spatial and temporal patterns are observed, with generally significant trends toward earlier springs/break‐up dates over most of western Canada and little change in isotherm and freeze‐up dates over the majority of the country in autumn. Strong correlations (r > 0·5) between 0 °C isotherm dates and freeze‐up/break‐up dates at many locations across the country reveal the high synchrony of these variables. These results are also consistent with more recent observations of other cryospheric and atmospheric variables that indicate, in particular, a general trend toward earlier springs in the latter part of the 20th century. The results of this study provide further evidence of the robustness of lake ice as a proxy indicator of climate variability and change. Copyright © 2006 John Wiley & Sons, Ltd.
Docetaxel and gemcitabine combination in 133 advanced soft‐tissue sarcomas: A retrospective analysis
Authors: Bay Jacques‐Olivier , Ray‐Coquard Isabelle , Fayette Jérôme , Leyvraz Serge , Cherix Stephane , Piperno‐Neumann Sophie , Chevreau Christine , Isambert Nicolas , Brain Etienne , Emile Georges , Le Cesne Axel , Cioffi Angela , Kwiatkowski Fabrice , Coindre Jean‐Michel , Bui Nguyon Binh , Peyrade Frédéric , Blay Jean‐Yves ,   for the Groupe Sarcome Français
Published: February 2006

Advanced soft‐tissue sarcomas are usually resistant to cytotoxic agents such as doxorubicin and ifosfamide. Antitumor activity has been observed for gemcitabine and docetaxel combination. We conducted a retrospective study on 133 patients (58 males/75 females) with unresectable or metastatic soft‐tissue sarcoma. The median age at diagnosis was 51.7 (18–82), with 76 patients with leiomoyosarcoma and 57 patients with other histological subtypes. The initial localizations were limb (44), uterine (32), retroperitoneal (23) and organs or bone (34). Patients received 900 mg/m2 of gemcitabine (days 1 and 8) over 90 min plus 100 mg/m2 of docetaxel (day 8), intravenously every 21 days. Gemcitabine/docetaxel combination was well tolerated with an overall response of 18.4% and with no clear statistical difference between leiomyosarcomas and other histological subtypes (24.2% versus 10.4% (p = 0.06)). No difference was found between uterine soft‐tissue sarcomas versus others. The median overall survival was 12.1 months (1–28). Better overall survival was correlated with leiomyosarcoma (p = 0.01) and with the quality of the response, even for patients with stable disease (p < 10−4). No statistical difference was found for the initial localization. Response to treatment and overall survival were better for patients in World Health Organization (WHO) performance status classification (PS) 0 at baseline versus patients in WHO PS‐1, 2 or 3 (p = 0.023 and p < 10−4, respectively). Gemcitabine/docetaxel combination was tolerable and demonstrated better response and survival for leiomyosarcoma, especially for patients in WHO PS‐0 at baseline. For the other histological subtypes, the response was not encouraging, but the survival for patients in response or stable suggests further investigation. © 2006 Wiley‐Liss, Inc.
Identification of limited regions of genetic aberrations in patients affected with Wilms' tumor using a tiling‐path chromosome 22 array
Authors: Benetkiewicz Magdalena , de Ståhl Teresita Díaz , Gördör Anita , Pfeifer Susan , Wittmann Stefanie , Gessler Manfred , Dumanski Jan P.
Published: February 2006

Wilms' tumor (WT) is one of the most common solid tumors of childhood. The genetics of this disorder is complex and few studies have suggested allelic loss of chromosome 22 as a frequent aberration. To assess tumor‐ and possible germline‐specific regions affected with gene copy number variations on this chromosome, we applied a high‐resolution genomic clone‐based chromosome 22 array to a series of 28 WT samples and the paired blood‐derived DNA of the patients. The group of tumors was enriched for cases with metastases, relapse or fatal outcome, criteria that were expected to yield a higher number of alterations on chromosome 22. Overall, the array‐based form of comparative genomic hybridization (array‐CGH) analysis revealed genomic changes in 53% (15 out of 28) of cases. We identified hemizygous deletion of the whole arm of 22q in 3 tumors (11%). Furthermore, a complex amplifier genotype was detected in 8 samples, presenting regions of gain along the chromosome, which defined 7 distinct minimal overlapping segments. The distribution of aberrations in 4 additional cases displaying regional genomic imbalances delimited 2 tumor suppressor/oncogene candidate loci, 1 in the proximal and the other in the terminal part of 22q. Analysis of these regions revealed the presence of several candidate genes that may play a role in the development of WT. These findings demonstrate the power of array‐CGH in the determination of DNA copy number alterations and further strength the notion that WT‐associated genes exist on this chromosome. © 2006 Wiley‐Liss, Inc.
Id‐1 promotes proliferation of p53‐deficient esophageal cancer cells
Authors: Hui Cheuk Man , Cheung Pak Yan , Ling Ming Tat , Tsao Sai Wah , Wang Xianghong , Wong Yong Chuan , Cheung Annie L.M.
Published: February 2006

The helix‐loop‐helix protein inhibitor of differentiation and DNA binding (Id‐1) is known to promote cellular proliferation in several types of human cancer. Although it has been reported that Id‐1 is over‐expressed in esophageal squamous cell carcinoma (ESCC), its function and signaling pathways in esophageal cancer are unknown. In our study, we investigated the direct effects of Id‐1 on esophageal cancer cell growth by transfecting an Id‐1 expression vector into an ESCC cell line (HKESC‐3), which showed serum‐dependent Id‐1 expression. Ectopic Id‐1 expression resulted in increased serum‐independent cell growth and G1‐S phase transition, as well as up‐regulation of mouse double minute 2 (MDM2) and down‐regulation of p21Waf1/Cip1 protein expressions in the transfectant clones in a p53‐independent manner. However, overexpression of Id‐1 had no effect on the pRB, CDK4 and p16INK4A expressions. Stable transfection of Id‐1 antisense expression vector to inhibit the expression of endogenous Id‐1 in another ESCC cell line (HKESC‐1) reversed the effects on MDM2 and p21Waf1/Cip1. In addition, Id‐1 expression protected ESCC cells from Tumor Necrosis Factor (TNF)‐α‐induced apoptosis by up‐regulating and activating Bcl‐2. In conclusion, our study provides evidence for the first time that Id‐1 plays a role in both proliferation and survival of esophageal cancer cells. Our findings also suggest that unlike prostate, hepatocellular and nasopharyngeal carcinomas in which Id‐1 induces cell proliferation through inactivation of p16INK4A/RB pathway, the increased cell proliferation observed in ESCC cells may be mediated through a different mechanism. © 2006 Wiley‐Liss, Inc.
The adhesion molecule L1 (CD171) promotes melanoma progression
Authors: Meier Friedegund , Busch Silke , Gast Daniela , Göppert Anne , Altevogt Peter , Maczey Evelyn , Riedle Svenja , Garbe Claus , Schittek Birgit
Published: February 2006

The adhesion molecule L1 is expressed in primary melanomas and cutaneous metastases in contrast to melanocytic nevi and melanocytes, and is significantly associated with metastatic spread. Recent studies have demonstrated that in carcinomas L1 expression is associated with sustained activation of the extracellular signal‐regulated kinase (ERK) pathway and upregulation of ERK‐dependent, motility‐ and invasion‐associated gene products including αvβ3 integrin. The objective of this study was to further investigate the role of the adhesion molecule L1 in melanoma progression, and to evaluate whether targeting the L1 adhesion molecule would have therapeutic effects against invasive melanoma growth. Using human melanoma cells from different stages of progression in monolayer and organotypic human skin culture mimicking the pathophysiological environment of cutaneous melanoma, we found that (1) L1 expression mostly correlates with melanoma progression and αvβ3 integrin expression, (2) overexpression of L1 in early radial growth phase melanoma cells promotes conversion from radial to vertical growth phase melanoma without upregulation of αvβ3 integrin expression, and (3) suppression of L1 function significantly reduces migration and invasion of melanoma cells, but does not completely block invasive melanoma growth. Altogether, L1 plays a critical role in melanoma invasion and progression and offers therapeutic potential in combination with conventional anticancer agents. © 2006 Wiley‐Liss, Inc.
Helicobacter pylori IgA and IgG antibodies, serum pepsinogen I and the risk of gastric cancer: Changes in the risk with extended follow‐up period
Authors: Knekt Paul , Teppo Lyly , Aromaa Arpo , Rissanen Harri , Kosunen Timo U.
Published: February 2006

The prediction of Helicobacter pylori antibodies immunoglobulin A (IgA) and immunoglobulin G (IgG) and serum pepsinogen I (PG I) on gastric cancer occurrence was studied in a nested case‐control study, based on 225 incident cancer cases and 435 matched controls from a Finnish cohort followed from 1966–1991. The odds ratio of noncardia gastric cancer between infected and noninfected persons was 3.12 (95% confidence interval (CI) = 1.97–4.95) for elevated IgA and 2.88 (CI: 1.63–5.07) for elevated IgG antibodies. The odds ratio between low and high PG I was 2.24 (CI: 1.43–3.49). The strength of association was significant for IgA antibodies during the total follow‐up, but for IgG antibodies this was only true for follow‐up periods of 15 years or more. IgA antibodies were significantly associated with all registered histological subtypes apart from intestinal type adenocarcinoma. The highest gastric cancer risk was found among individuals with simultaneously elevated IgA and IgG antibodies and low PG I with an odds ratio of 10.9 (CI: 4.31–27.7) in comparison with those who were negative for both antibodies and had normal PG I. Elevated IgA and IgG antibodies and low PG I were not associated with cancers of the gastric cardia. The findings support the hypothesis that H. pylori infection is a cause of noncardia gastric cancer. Although elevated H. pylori IgA and IgG antibodies and low PG I independently could predict the occurrence of noncardia gastric cancer, their power to do so varied with the stage and length of the follow‐up period and it increased when they were applied in combination. © 2006 Wiley‐Liss, Inc.
Breast cancer in Belarus and Ukraine after the Chernobyl accident
Authors: Pukkala Eero , Kesminiene Ausra , Poliakov Semion , Ryzhov Anton , Drozdovitch Vladimir , Kovgan Lina , Kyyrönen Pentti , Malakhova Irina V , Gulak Liudmila , Cardis Elisabeth
Published: February 2006

An increase in breast cancer incidence has been reported in areas of Belarus and Ukraine contaminated by the Chernobyl accident and has become an issue of public concern. The authors carried out an ecological epidemiological study to describe the spatial and temporal trends in breast cancer incidence in the most contaminated regions of Belarus and Ukraine, and to evaluate whether increases seen since 1986 correlate to radiation exposure from the Chernobyl accident. The authors investigated the trends through age‐cohort‐period‐region analyses of district‐specific incidence rates of breast cancer for Gomel and Mogilev regions of Belarus and Chernigiv, Kyiv and Zhytomir regions of Ukraine. Dose‐response analyses were based on Poisson regression, using average district‐specific whole body doses accumulated since the accident from external exposure and ingestion of long‐lived radionuclides. The study demonstrated increases in breast cancer incidence in all areas following the Chernobyl accident, reflecting improvements in cancer diagnosis and registration. In addition, a significant 2‐fold increase in risk was observed, during the period 1997–2001, in the most contaminated districts (average cumulative dose of 40.0 mSv or more) compared with the least contaminated districts (relative risk [RR] in Belarus 2.24, 95% confidence interval [CI] 1.51–3.32 and in Ukraine 1.78, 95% CI = 1.08–2.93). The increase, though based on a relatively small number of cases, appeared approximately 10 years after the accident, was highest among women who were younger at the time of exposure and was observed for both localised and metastatic diseases. It is unlikely that this excess could be entirely due to the increased diagnostic activity in these areas. © 2006 Wiley‐Liss, Inc.
The process and promise of mental health augmentation of nurse home‐visiting programs: Data from the Louisiana Nurse–Family Partnership
Authors: Boris Neil W. , Larrieu Julie A. , Zeanah Paula D. , Nagle Geoffrey A. , Steier Alison , McNeill Patricia
Published: February 2006

The Nurse–Family Partnership (NFP) model is a well‐studied and effective preventive intervention program targeting first‐time, impoverished mothers and their families. Data documenting the negative impact of maternal depression and partner violence on the developing young child can be used to make a strong case for augmenting NFP programs to focus on mental health problems impacting the mother–child relationship. This article reviews the rationale for and process of augmenting an NFP program in Louisiana. Data on the prevalence of depression and partner violence in our sample are presented alongside a training protocol for nurses and mental health consultants designed to increase the focus on infant mental health. The use of a weekly case conference and telephone supervision of mental health consultants as well as reflections on the roles of the mental health consultant and the nurse supervisor are presented.
Collageneous matrix coatings on titanium implants modified with decorin and chondroitin sulfate: Characterization and influence on osteoblastic cells
Authors: Bierbaum Susanne , Douglas Timothy , Hanke Thomas , Scharnweber Dieter , Tippelt Sonja , Monsees Thomas K. , Funk Richard H. W. , Worch Hartmut
Published: February 2006

Studies in developmental and cell biology have established the fact that responses of cells are influenced to a large degree by morphology and composition of the extracellular matrix. Goal of this work is to use this basic principle to improve the biological acceptance of implants by modifying the surfaces with components of the extracellular matrix (ECM), utilizing the natural self‐assembly potential of collagen in combination with further ECM components in close analogy to the situationin vivo. Aiming at load‐bearing applications in bone contact, collagen type I in combination with the proteoglycan decorin and the glycosaminoglycan chondroitin sulfate (CS) was used; fibrillogenesis, fibril morphology, and adsorption of differently composed fibrils onto titanium were assessed. Both decorin and CS could be integrated into the fibrils during fibrillogenesis, the amount bound respectively desorbed depending on the ionic strength of fibrillogenesis buffer. Including decorin always resulted in a significant decrease of fibril diameter, CS in only a slight decrease or even increase, depending on the collagen preparation used. No significant changes in adsorption to titanium could be detected. Osteoblastic cells showed different reactions for cytoskeletal arrangement and osteopontin expression depending on the composition of the ECM, with CS enhancing the osteoblast phenotype. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Enhanced osteogenic promotion around dental implants with synthetic binding motif mimicking bone morphogenetic protein (BMP)‐2
Authors: Seol Yang‐Jo , Park Yoon‐Jeong , Lee Sang‐Cheol , Kim Kyoung‐Hwa , Lee Jue‐Yeon , Kim Tae‐Il , Lee Yong‐Moo , Ku Young , Rhyu In‐Chul , Han Soo‐Boo , Chung Chong‐Pyoung
Published: February 2006

Synthetic receptor binding motif mimicking bone morphogenetic protein‐2 (BMP‐2) was covalently linked to titanium (Ti) surfaces through a chemical conjugation process. The composition and properties of surface‐modified Ti were investigated by XPS as well as by measuring surface radioactivity. In vitro tests were conducted with osteoblast‐like MC3T3‐E1 cells to assess cell attachment, morphology, and expression of osteogenic marker in the cells grown on modified Ti surfaces. In addition, in vivo experiments involved implants in mandibular bone defects of beagles to evaluate the effect of surface modification on bone regeneration. Results of XPS measurements showed a complete and homogeneous peptide overlayer on the Ti surfaces; the content was further measured by gamma counting. Biological evaluations showed that the biochemically modified Ti samples were active in terms of cell attachment behavior. The MC3T3‐E1 cell growth rate, marker protein expression, and alkaline phosphatase production of the peptide‐modified surfaces were all higher than those of control Ti. Importantly, the implants in the canine mandibles showed significant increase of bone growth when modified with bioactive peptide, thereby confirming that biochemical modifications of Ti surfaces can enhance the rate of bone healing as compared with untreated Ti surfaces. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Changes in color and translucency of porcelain‐repairing resin composites after thermocycling
Authors: Choi Mi‐Sook , Lee Yong‐Keun , Lim Bum‐Soon , Rhee Sang‐Hoon , Yang Hyeong‐Cheol , Lim Young‐Jun
Published: February 2006

The objective of this study was to determine the changes in color and translucency of dental porcelain‐repairing resin composites compared to dental porcelain after thermocycling. Color and spectral reflectance of three shades (A2, A3, and A3.5) of one brand of dental porcelain and three basic shades (A2, A3, and A3.5) and three combinations (A2/A3, A3/3.5, and A2/A3.5) of three brands of porcelain‐repairing resin composites (ABT, FSP, and TCR) were measured, before and after thermocycling for 3000 cycles, relative to the illuminant D65. The specimen was 2 mm in thickness, and 1 mm of each shade was layered to make combined shades. Changes in color (ΔE*ab) and translucency parameter (ΔTP) were calculated. A general linear model by the material (porcelain or resin composite) and shade was used to compare differences (α = 0.05). The range of color changes was 0.68–1.67 in porcelain, 0.56–1.30 in ABT, 2.28–3.10 in FSP, and 0.36–1.15 in TCR. The range of ΔTP was 0.45–0.96 in porcelain, −0.48 to 0.94 in ABT, −1.31 to 0.82 in FSP, and −0.51 to 1.91 in TCR. After thermocycling, changes in color and TP were correlated with the shade of the material, but not with the material. The discrepancy in the changes of color and translucency after thermocycling between porcelain and porcelain‐repairing resin composites should be considered when selecting repairing materials. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
New concept of resin‐dentin interfacial adhesion: The nanointeraction zone
Authors: Koshiro Kenichi , Sidhu Sharanbir K. , Inoue Satoshi , Ikeda Takatsumi , Sano Hidehiko
Published: February 2006

The purpose of this study was to evaluate the morphological appearance of resin‐dentin interface produced by 1‐step adhesive systems in order to classify them, using TEM. It was hypothesized that all interfaces produced by each 1‐step adhesive show characteristics similar to that produced by the conventional self‐etching system rather than that produced by etch‐and‐rinse system. The flattened dentin surfaces were subjected to bonding treatment using either a 2‐step adhesive: single bond, mega bond, unifil bond; or a 1‐step adhesive: Prompt L‐Pop, absolute, xeno CF, AQ bond, one‐up bond F, G bond, and SSB‐200. A flowable resin was then applied to these surfaces. The results revealed that resin‐dentin interfaces produced by 1‐step systems were classified into three categories. Additionally, the interface produced by G bond and SSB‐200 showed a different morphological appearance from that of the others. The interface produced by these adhesives was thinner and less demineralized, with the presence of hydroxyapatite‐coated collagen fibrils. It is proposed that “Nanointeraction Zone (NIZ)” is a new complementary classification for partially demineralized resin‐dentin interdiffusion zones. Thus, one‐step self‐etching adhesive systems can be classified into three categories, etch‐and‐rinse type, mild self‐etching type, and NIZ type, by their morphological appearance of the interface. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Contemporary alumina‐on‐alumina total hip arthroplasty performed in patients younger than forty years: A 5‐year minimum follow‐up study
Authors: Yoo Jeong Joon , Kim Young‐Min , Yoon Kang Sup , Koo Kyung‐Hoi , Kim Jong Won , Nam Kwang Woo , Kim Hee Joong
Published: February 2006

Ceramic‐on‐ceramic bearing surfaces in total hip arthroplasties (THAs) are an attractive alternative coupling and may offer a promising option for young active patients. We evaluated the clinical results of 72 contemporary primary cementless alumina‐on‐alumina THAs performed in 61 patients younger than 40 years (mean age, 30 years), after a 5‐year minimum follow‐up. Most patients (97%) were able to return to their prearthritic activity levels, and none changed occupation because of a postoperative hip joint problem. No implant loosened radiographically and no stem or cup was revised. Ceramic wear was undetectable in 24 hips, where differentiation of the femoral head from the cup was possible on radiographs and no osteolysis was observed. One ceramic fracture following a major motor vehicle accident and a recurrent subluxation‐associated ceramic liner edge fracture attributed to inadequate hip muscle tone occurred. We believe that this alternative articulation offers a promising option for young active patients. However, our findings also suggest that contemporary ceramic implant fracture is not a potential, but a real danger. Careful preoperative patient evaluation, proper indications for ceramic bearings, and meticulous surgical techniques are recommended to minimize the possibility of modern ceramic failure. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Tissue engineering of articular cartilage with autologous cultured adipose tissue‐derived stromal cells using atelocollagen honeycomb‐shaped scaffold with a membrane sealing in rabbits
Authors: Masuoka Kazunori , Asazuma Takashi , Hattori Hidemi , Yoshihara Yasuo , Sato Masato , Matsumura Kouji , Matsui Takemi , Takase Bonpei , Nemoto Koichi , Ishihara Masayuki
Published: February 2006

Adipose tissue derived stromal cells (ATSCs), which were isolated from adipose tissue of rabbit, have shown to possess multipotential, that is, they differentiate into osteoblasts and adipocytes in plate‐culturing and into chondrocytes in an established aggregate culture using defined differentiation‐inductive medium. The aim of this study was to evaluate the utility of ATSCs in tissue engineering procedures for repair of articular cartilage‐defects using the atelocollagen honeycomb‐shaped scaffold with a membrane sealing (ACHMS‐scaffold). We intended to repair full‐thickness articular cartilage defects in rabbit knees using autologously cultured ATSCs embedded in the ACHMS‐scaffold. ATSCs were incubated within the ACHMS‐scaffold to allow a high density and three‐dimensional culture with control medium. An articular cartilage defect was created on the patellar groove of the femur, and the defect was filled with the ATSCs‐containing ACHMS‐scaffold, ACHMS‐scaffold alone, or empty (control). Twelve weeks after the operation, the histological analyses showed that only the defects treated with the ATSCs‐containing ACHMS‐scaffold were filled with reparative hyaline cartilage, highly expressed Type II collagen. These results indicate that transplantation of autologous ATSCs‐containing ACHMS‐scaffold is effective in repairing articular cartilage defects. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Gene expression profiling of androgen receptor antagonists in the rat fetal testis reveals few common gene targets
Authors: Mu Xueyan , Liu Kejun , Kleymenova Elena , Sar Madhabananda , Young S. Stanley , Gaido Kevin W.
Published: February 2006

The androgen receptor (AR) is expressed in the fetal testis; however, the role of AR in fetal testicular development is poorly understood. Disrupted AR activity and subsequent gene expression alterations may disturb developmental programming of the fetal testis and result in testicular abnormalities later in life. The present study was performed to examine global gene expression patterns in rat fetal testis following in utero exposure to various AR antagonists. Pregnant Sprague‐Dawley rats were treated with flutamide (50 mg/kg/day), linuron (50 mg/kg/day), vinclozolin (200 mg/kg/day), p,p′‐DDE (100 mg/kg/day) or corn oil vehicle by gavage daily from gestation day (GD) 12 –19. Testes were isolated on GD 19, and AR immunostaining, histology, and global changes in gene expression were determined. There were no alterations in the pattern or expression level of AR and no apparent histological changes in the fetal testes in any treatment group. Microarray analysis using Dunnett's test with multiple testing correction revealed no significant gene expression alterations following exposure to flutamide, linuron, vinclozolin, and p,p′‐DDE. A less stringent analysis yielded some chemical specific effects on gene expression, and these effects were further evaluated by real‐time RT‐PCR. Vinclozolin treatment reduced the expression of several genes involved in cholesterol biosynthesis, though the testosterone levels were unchanged in the fetal testes in any treatment group. In flutamide, linuron, and p,p′‐DDE treatment groups, the expression of hemoglobin Y, beta‐like embryonic chain (Hbb‐y) was reduced. Myomesin 2 (Myom2) expression was increased following linuron treatment. Given the lack of a common set of genes and the absence of overt histopathology, we conclude that the fetal testis is not a major target for AR activity at this stage of development although some cell‐type specific gene expression changes cannot be ruled out. © 2006 Wiley Periodicals, Inc. J Biochem Mol Toxicol 20:7–17, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20110
Splicing of scorpion toxin gene BmKK2 in HEK 293T cells
Authors: Zhijian Cao , Chao Dai , Shijin Yin , Yingliang Wu , Jiqun Sheng , Yonggang Sha , Wenxin Li
Published: February 2006

Using GFP as a reporter gene, splicing of scorpion toxin gene BmKK2 was investigated in cultured HEK 293T cells. The results of RT‐PCR and western blotting showed that BmKK2's intron could be recognized and spliced in cultured HEK 293T cells. At the same time, a cryptic splicing site of BmKK2 gene was found at the 91st nucleotide site of the second exon, which is a typical form of alternative splicing. For the first time, alternative splicing would partially explain the diversity of scorpion toxins at the gene level. Moreover, replacing BmKK2's intron with BmP03's intron (an artificial BmKK2‐BmP03 mosaic gene) did not affect the intron's recognition and splicing, but increased the expression of the toxin‐GFP fusion protein by fluorescence imaging, which indicated that both introns may regulate the expression of toxin‐GFP fusion protein. The artificial BmKK2‐BmP03 mosaic gene was also spliced into two kinds of mRNA molecules, which showed that sequence of intron was not absolutely conserved. The results suggested that introns of scorpion toxin genes BmKK2 and BmP03 increase the diversity of scorpion toxins and regulate the expression of their genes. © 2006 Wiley Periodicals, Inc. J Biochem Mol Toxicol 20:1–6, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20111
Effects of the paratemnus elongatus pseudoscorpion venom in the uptake and binding of the L‐glutamate and GABA from rat cerebral cortex
Authors: dos Santos Wagner Ferreira , Coutinho‐Netto Joaquim
Published: February 2006

L‐Glu is the most important and widespread excitatory neurotransmitter of the vertebrates. Four types of receptors for L‐glu have been described. This neurotransmitter modulates several neuronal processes, and its dysfunction causes chronic and acute diseases. L‐Glu action is terminated by five distinct transporters. Antagonists for these receptors and modulators of these transporters have anticonvulsant and neuroprotective potentials, as observed with the acylpoliamines and peptides isolated from spiders, solitary and social wasp venoms. On the other hand, the major inhibitory neurotransmitter in mammalian nervous tissue is the GABA. Drugs that enhance GABA neurotransmission comprise effective approaches to protecting the brain against neuronal injury. Is this study, we demonstrate for the first time the inhibition of the [3H]L‐glu binding to its specific sites in synaptosomal membranes from rat cerebral cortex, produced by 0.027 U of Paratemnus elongatus venom (EC50). The venom of P. elongatus changes Km and Vmax into the high affinity uptake of the L‐glu and decreases Km and Vmax into the parameters of the GABA uptake from rat synaptosomes. This leads us to speculate on the possible presence of selective and specific compounds in this venom that act in L‐glu and GABA dynamics, and therefore, that can serve as tools and new drug models for understanding these neurotransmissions. © 2006 Wiley Periodicals, Inc. J Biochem Mol Toxicol 20:27–34, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20113
Monitoring of an industrial wastewater plant employing finite‐time convergence observer
Authors: Aguilar‐López Ricardo , Martínez‐Guerra Rafael , Mendoza‐Camargo Juan , Neria‐González María Isabel
Published: February 2006

In this paper, the estimation of non measured variables (bioreactor biomass and settler biomass concentrations) is addressed. The plant is subjected to sudden step disturbances on the inlet oxygen flow, such that an observer with finite‐time convergence is required, to maintain adequate estimation performance. The observer structure contains a fractional power of the estimation error which is proposed to ensure the convergence properties needed. Under the assumptions considered, a mathematical analysis is performed to demonstrate the convergence of the estimation error and the convergence time is also calculated. The performance of the observer is illustrated with numerical experiments and compared with standard nonlinear Luenberger observer. Copyright © 2006 Society of Chemical Industry
Quiescent gemmules of the freshwater sponge, Spongilla lacustris (Linnaeus, 1759), contain remarkably high levels of Hsp70 stress protein and hsp70 stress gene mRNA
Authors: Schill Ralph O. , Pfannkuchen Martin , Fritz Gisela , Köhler Heinz‐r. , Brümmer Franz
Published: February 2006

With the onset of changing environmental conditions in autumn, the freshwater sponge Spongilla lacustris (Linnaeus, 1759) produces resistant stages (gemmules) which are in the state of quiescence. Gemmules stored at 8°C remained quiescent; however, germination occurred within 24 hr after the water temperature was increased to 22.5°C. Sponges hatched through the micropyle and subsequently built new spicules and a new canal system. The molecular and biochemical mechanisms which enable the gemmules to survive long periods of adverse conditions are not known. For the first time we focused on the role of the stress protein Hsp70 and the expression of hsp70 mRNA in S. lacustris during the development of gemmules in the state of quiescence into growing sponges. The partial sequence of hsp70 seems to be a true hsp gene since transcription could be clearly enhanced by temperature elevation. The results showed a large pool of cellular Hsp70 and hsp70 mRNA in gemmules during the state of quiescence. Within hours after a temperature trigger, the Hsp70 level decreased slowly and reached approximately the level of an adult sponge. Hsp70 presumably allows gemmules to stabilize their proteins and membranes during dormancy from autumn to spring when water temperatures change. J. Exp. Zool. 305A, 2006. © 2006 Wiley‐Liss, Inc.
Developmental and evolutionary origins of the vertebrate dentition: molecular controls for spatio‐temporal organisation of tooth sites in osteichthyans
Authors: Fraser Gareth J. , Graham Anthony , Smith Moya M.
Published: February 2006

The rainbow trout (Oncorhynchus mykiss) as a developmental model surpasses both zebrafish and mouse for a more widespread distribution of teeth in the oro‐pharynx as the basis for general vertebrate odontogenesis, one in which replacement is an essential requirement. Studies on the rainbow trout have led to the identification of the initial sequential appearance of teeth, through differential gene expression as a changing spatio‐temporal pattern, to set in place the primary teeth of the first generation, and also to regulate the continuous production of replacement tooth families. Here we reveal gene expression data that address both the field and clone theories for patterning a polyphyodont osteichthyan dentition. These data inform how the initial pattern may be established through up‐regulation at tooth loci from a broad odontogenic band. It appears that control and regulation of replacement pattern resides in the already primed dental epithelium at the sides of the predecessor tooth. A case is presented for the developmental changes that might have occurred during vertebrate evolution, for the origin of a separate successional dental lamina, by comparison with an osteichthyan tetrapod dentition (Ambystoma mexicanum). The evolutionary origins of such a permanent dental lamina are proposed to have occurred from the transient one demonstrated here in the trout. This has implications for phylogenies based on the homology of teeth as only those developed from a dental lamina. Utilising the data generated from the rainbow trout model, we propose this as a standard for comparative development and evolutionary theories of the vertebrate dentition. J. Exp. Zool. (Mol. Dev. Evol.) 306B, 2006. © 2006 Wiley‐Liss, Inc.
From conical to spatulate: Intra‐ and interspecific changes in tooth shape in closely related cichlids (Teleostei; Cichlidae: Eretmodini)
Authors: Vandervennet E. , Wautier K. , Verheyen E. , Huysseune A.
Published: February 2006

The Eretmodini are closely related cichlids endemic to Lake Tanganyika with very divergent oral tooth shapes, ranging from spatulate in Eretmodus to conical in Tanganicodus. To study how closely related cichlids can generate such divergent tooth shapes, we investigated how the enamel organ directs the development of spatulate teeth in Eretmodus cf. cyanostictus (lineage A), both in ontogeny and in adults, and of conical teeth in adult Tanganicodus cf. irsacae, using 3D‐reconstructions from serially sectioned tooth germs. The spatulate oral tooth shape that characterizes adult E. cf. cyanostictus (lineage A) is preceded early in ontogeny by a conical tooth shape. We propose two possible hypotheses to account for changes in the folding of the enamel organ (in particular its epithelio‐mesenchymal boundary) capable of generating such distinct tooth shapes. Different arguments lead us to favor the hypothesis of an asymmetric growth and differentiation of the enamel organ, such that the tip of a conical tooth corresponds to one “corner” of a spatulate tooth. Applying current molecular models of tooth shape variation, this would imply the existence of asymmetric fields of inhibition. Whether such asymmetric growth reflects the reutilization of a simple mechanism operating in ontogeny has to be clarified. J. Morphol. © 2006 Wiley‐Liss, Inc.
Variations due to analysis technique in intracellular pH measurements in simulated and in vivo 31P MR spectra of the human brain
Authors: Hamilton Gavin , Allsop Joanna M. , Patel Nayna , Forton Daniel M. , Thomas Howard C. , O'Sullivan Catherine P.A. , Hajnal Joseph V. , Taylor‐Robinson Simon D.
Published: February 2006

Purpose

To investigate variation in pH generated by different analysis techniques and to find the most robust method, 31P MR brain spectra were acquired in vivo. Three different methods were used to measure the chemical shift of inorganic phosphate (Pi) relative to phosphocreatine (PCr).

Materials and Methods

Eight healthy volunteers were scanned four times, and manual measurement of the chemical shift in a frequency domain spectrum using the manufacturer's software was compared with values produced by a frequency‐domain analysis method (NMR1) and a prior‐knowledge‐based time‐domain technique (MRUI). To explain the in vivo data, simulations of brain spectra, modified in ways typical of real variations in vivo, were produced and the pH was measured using manual measurement and MRUI.

Results

Different measurement techniques produced systematically different pH values, with manual measurement producing the lowest variability (manual measurement: pH = 6.999, CoV = 0.297; NMR1: pH = 7.042, CoV = 0.501; MRUI: pH = 7.036, CoV = 0.606). While MRUI more accurately measured the pH of unaltered simulations, it was systematically affected by altering the simulated spectra. Manual measurement was unaffected.

Conclusion

Manual measurement produces the most consistent pH value, and there is no benefit in using more complex automated spectral fitting methods to measure the pH. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
The atmospheric pressure Meerwein reaction
Authors: Meurer Eduardo C. , Eberlin Marcos N.
Published: February 2006

We have already shown that the in‐vacuum gas‐phase Meerwein reaction of (thio)acylium ions is general in nature and useful for class‐selective screening of cyclic (thio)epoxides. Herein we report that this gas‐phase reaction can also be performed efficiently at atmospheric pressure under both electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) conditions. This alternative expands the range of molecules that can be reacted by gas‐phase Meerwein reaction. Phenyl epoxide, thiirane, 3‐methoxy‐2,2‐dimethyloxirane, propylene oxide, 2,2′‐bioxirane, trans‐1,3‐diphenyl‐2,3‐epoxypropan‐1‐one, epichloridrine and propylene oxide are shown to react efficiently in both ESI and APCI conditions. Tetramethylurea (TMU) and (thio)TMU were both used as dopants, being co‐injected with either toluene, acetonitrile or methanol solutions of the (thio)epoxides, with similar results. In both ESI and APCI, (thio)TMU is protonated preferentially, and these labile species dissociate promptly to yield (CH3)2NC+O and (CH3)2NCS+, which are the least acidic and most reactive (thio)acylium ions so far tested in the gas‐phase Meerwein reaction. Under the low‐energy ESI conditions set to favor both the formation of the (thio)acylium ion and ion/molecule reactions, (CH3)2NCO(S)+ react competitively with (thio)TMU to form acylated (thio)TMU and with the (thio)epoxide to form the characteristic Meerwein products. Enhanced selectivity in structural characterization or for the screening of (thio)epoxides is achieved by performing on‐line collision‐induced dissociation of Meerwein products, particularly for the more structurally complex (thio)epoxides. Copyright © 2006 John Wiley & Sons, Ltd.