bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis, radiolabelling characteristics and biological evaluation of the derivatives of mercaptoacetyltriglycine
Authors: Okarvi S. M. , Adriaens P. , Verbruggen A. M. 
Published: November 2005

Summary
Several derivatives of MAG3, in which one or both of the first two amide bonds are inverted and contain an additional methyl or carboxyl-substituent on the ligand backbone, have been synthesized and evaluated. This was realized by substituting a glycyl with a D- or L-alanyl moiety or by replacing cysteamine with an L-cysteine to investigate the renal characteristics of the resulting derivatives versus the reference 99mTc-MAG3. Labelling with 99mTc resulted in two main radioactive species, which probably are the isomeric oxo-technetium complexes. These complexes were separated by HPLC and evaluated in mice. The data suggest that the substitution in the amide functions and addition of a methyl or carboxyl moiety results in poor renal handling of these compounds. However, one of the derivatives 99mTc-C-LB, exhibits renal characteristics comparable to 99mTc-MAG3.
Shiga‐like Toxin Subunit B (SLTB)‐Enhanced Delivery of Chlorin e6 (Ce6) Improves Cell Killing
Authors: Tarragó‐Trani Maria Teresa , Jiang Shu , Harich Kim C. , Storrie Brian 
Published: November 2005

ABSTRACTWe used Shiga‐like toxin B subunit (SLTB) to deliver the photosensitizer, chlorin e6 (Ce6), to Vero cells expressing the Gb3 receptor. Our aim was to provide an example of carrier‐enhanced photodynamic cell killing with which to start a systematic consideration of photosensitizer delivery at the subcellular level. SLTB, in contrast to many other potential protein carriers, is delivered intracellularly to the Golgi apparatus and endoplasmic reticulum (ER). Ce6 was chosen both for its phototoxic properties and its potential for covalent conjugation with SLTB. Ce6‐SLTB after cleanup contained 10% noncovalently bound Ce6. The noncovalent binding of porphyrins and chlorins to protein conjugates has been well documented, and hence the effective cleanup procedure is a significant accomplishment. We demonstrate that Ce6‐SLTB enhances delivery of Ce6 to target cells as compared to free Ce6. In Vero cells, Ce6‐SLTB was over an order of magnitude more photodynamically toxic than free Ce6. Moreover, we show that in the case of Ce6‐SLTB, photosensitizer accumulation is in a combination of subcellular sites including mitochondria, Golgi apparatus, ER and plasma membrane. The occurrence in nature of diverse B subunit binding sites and the possibilities of varied intracellular delivery make optimized use of B subunit carriers attractive.
Effect of Cloud Cover on UVB Exposure Under Tree Canopies: Will Climate Change Affect UVB Exposure?
Authors: Grant Richard H. , Heisler Gordon M. 
Published: November 2005

ABSTRACTThe effect of cloud cover on the amount of solar UV radiation that reaches pedestrians under tree cover was evaluated with a three‐dimensional canopy radiation transport model. The spatial distribution of UVB irradiance at the base of a regular array of spherical tree crowns was modeled under the full range of sky conditions. The spatial mean relative irradiance (I), and erythemal irradiance of the entire below‐canopy domain and the spatial mean relative irradiance and erythemal irradiance in the shaded regions of the domain were determined for solar zenith angles from 15° to 60°. The erythemal UV irradiance under skies with 50% or less cloud cover was not remarkably different from that under clear skies. In the shade, the actual irradiance was greater under partly cloudy than under clear skies. The mean ultraviolet protection factor for tree canopies under skies with 50% or less cloud cover was nearly equivalent to that for clear sky days. Regression equations of spatially averaged Ir. as a function of cloud cover fraction, solar zenith angle and canopy cover were used to predict the variation in erythemal irradiance in different land uses across Baltimore, MD.
Photoreactions of Cytochrome c Oxidase
Authors: Winterle John S. , Einarsdóttir Ólöf 
Published: November 2005

ABSTRACTThe photoreduction of oxidized bovine heart cytochrome c oxidase (CcO) by visible and UV radiation was investigated in the absence and presence of external reagents. In the former case, the quantum yields for direct photoreduction of heme A (heme a+ heme a3) were 2.6 ± 0.5 × 10−3, 4 ± 1 × 10−4, and 4 ± 2 × 10−6 with pulsed laser irradiation at 266,355 and 532 nm, respectively. Within experimental uncertainty, the quantum yields did not depend on pulse energy, implying that the mechanism is monophotonic. Irradiation with 355 nm light resulted in spectral changes similar to those produced independently by reduction with dithionite, whereby the low‐spin heme a and CuA are reduced first. Extended illumination at 355 and 532 nm yielded substantial amounts of reduced heme a3. Heme decomposition was noted with 266 nm light. In the presence of formate and cyanide ions, which bind at the binuclear heme a3/copper center in CcO, irradiation at 355 nm caused selective reduction of only the low‐spin heme a and CuA. The addition of ferrioxalate ion dramatically increased the efficiency of cytochrome c oxidase photoreduction. The quantum efficiency for heme A reduction was found to be near unity, significantly greater than for other known methods of photoreduction. The active reductant is most likely ferrous iron, and its reduction of the enzyme is thermodynamically driven by the reformation of ferrioxalate in the presence of excess oxalate ion. Other metalloenzymes with redox potentials similar to those of cytochrome c oxidase should be amenable to indirect photoreduction by this method.
Genetic Control of the Immune Response in Pathogenesis
Authors: Baker Pamela J. 
Published: November 2005

Background: Epidemiological studies have suggested that there is a genetic component to susceptibility to chronic periodontitis. Studies in humans and in animal models have suggested that some of the important components may be polymorphisms in key immunological genes.Methods: This paper summarizes previously published data from a mouse model in which alveolar bone loss is induced by oral infection with Porphyromonas gingivalis. Mice of different inbred immune‐normal strains were used, as well as the F1 heterozygotes from crosses between strains. In addition, tissue expression of an array of immunological genes was measured in the gingiva and spleen of these mice by quantitative reverse transcription‐polymerase chain reaction (QPCR).Results: Not all strains of mice are susceptible to bone loss. Intercross experiments demonstrate that susceptibility is an inherited trait. A subset of immunological genes tested showed differential basal expression in the gingiva or spleens (or both). Tumor necrosis factor and osteoprotegerin mRNAs are more highly expressed in the gingiva and interleukin‐1 mRNA is more highly expressed in both the gingiva and the spleens of susceptible mice than resistant mice. In the resistant mice, interleukin‐15 mRNA in the gingiva and Selp mRNA in the spleen are present at higher levels. In the resistant mice no genes changed expression after P. gingivalis infection, while mRNA for interleukin‐1, osteoprotegerin, and STAT6 all increased in the susceptible mice.Conclusions: Susceptibility and resistance are heritable traits. Strain differences in basal mRNA expression correlate with differences in susceptibility. Genes that change expression in response to infection also correlate with differences in susceptibility.
A Proposed Model Linking Inflammation to Obesity, Diabetes, and Periodontal Infections
Authors: Genco Robert J. , Grossi Sara G. , Ho Alex , Nishimura Fusanori , Murayama Yoji 
Published: November 2005

Background: Obesity is an important risk factor for diabetes, cardiovascular disease, and periodontal disease. Adipocytes appear to secrete proinflammatory cytokines which may be the molecules linking the pathogenesis of these diseases. We evaluated the relationship between obesity, periodontal disease, and diabetes mellitus insulin resistance as well as the plasma levels of tumor necrosis factor alpha (TNFα) and its soluble receptors (sTNFα) to assess the relationship of inflammation to obesity, diabetes, and periodontal infections.Methods: The relationship between periodontal disease, obesity, and insulin resistance was examined in the Third National Health and Nutrition Examination Survey (NHANES III). In a population of 12,367 non‐diabetic subjects, the variable body mass index (BMI) was used as an assessment of obesity and periodontal disease was assessed by mean clinical attachment loss. The plasma levels of TNFα and sTNFα were assessed in subsets of 1,221 adults from Erie County, New York, who represented the highest and lowest quartile of BMI. These subjects had extensive periodontal and medical evaluations.Results: In the NHANES III portion of the study, BMI was positively related to severity of periodontal attachment loss (P <0.001). Weighted multiple logistic regressions showed that this relationship is likely mediated by insulin resistance, since overweight individuals (with BMI ≥27 kg/m2) with high levels of insulin resistance (IR) exhibited an odds ratio of 1.48 (95% confidence interval 1.13 ‐ 1.93) for severe periodontal disease as compared to overweight subjects with low IR. In the Erie County adult population, the highest levels of TNFα and sTNFα receptors were found in those individuals in the highest quartile of BMI. A positive correlation of TNFα levels with periodontal disease was found only in those in the lowest quartile of BMI.Conclusions: Obesity is a significant predictor of periodontal disease and insulin resistance appears to mediate this relationship. Furthermore, obesity is associated with high plasma levels of TNFα and its soluble receptors, which in turn may lead to a hyperinflammatory state increasing the risk for periodontal disease and also accounting in part for insulin resistance. Further studies of the molecular basis of insulin resistance and its relationship to diabetes, periodontal disease, and obesity are necessary to fully test the hypothesis that adipocyte production of proinflammatory cytokines is a pathogenic factor linking obesity to diabetes and periodontal infections.
The Association Between Osteoporosis and Alveolar Crestal Height in Postmenopausal Women
Authors: Wactawski‐Wende Jean , Hausmann Ernest , Hovey Kathleen , Trevisan Maurizio , Grossi Sara , Genco Robert J. 
Published: November 2005

Background: Evidence supporting an association between osteoporosis and loss of alveolar crestal bone is limited. This study investigated that association in a large cohort of postmenopausal women.Methods: A cohort of 1,341 postmenopausal women aged 53 to 85 were assessed for alveolar crestal height (ACH) and bone density. ACH was determined from oral radiographs with subjects dichotomized by disease severity. Bone density was assessed by dual energy x‐ray absorptiometry, with severity determined by worst T score measured (normal >−1.00; low −1.00 to −2.00; moderate −2.01 to −2.49; osteoporotic <−2.5).Results: Compared to subjects in the normal T‐score group, the odds of worse ACH increased by 39%, 59%, and 230% for those in the low, moderate, and osteoporotic groups, respectively. Adjustment for weight, education, hormone use, calcium or vitamin D supplementation, and smoking did not appreciably change the findings. Further adjustment for age attenuated the association, with osteoporotic subjects having a 1.9‐fold increase of being in the worst ACH group (95% confidence interval [CI] 1.19 to 3.05). After age stratification, in women younger than 70 there was a significant trend by decreasing T‐score category (P <0.02). Osteoporotic subjects had worse ACH (odds ratio [OR] = 1.95; 95% CI 1.20 to 3.17). In women aged 70 and older, worse ACH was 2.5‐ to 4.6‐fold increased for decreasing T‐score category. After adjustment, the OR (95% CI) for the low, moderate, and osteoporotic groups were 2.66 (1.12 to 6.29), 2.31 (0.89 to 6.01), and 3.57 (1.42 to 8.97), respectively (P trend = 0.026).Conclusions: This study found a strong and consistent association between T score and ACH in postmenopausal women. Increasing age is an important modifier of that association.
Periodontitis and Airway Obstruction
Authors: Katancik James A. , Kritchevsky Stephen , Weyant Robert J. , Corby Patricia , Bretz Walter , Crapo Robert O. , Jensen Robert , Waterer Grant , Rubin Susan M. , Newman Anne B. 
Published: November 2005

Background: The objective of this study was to examine the relationship between airway obstruction and periodontal disease.Methods: Participants were a subset of 860 community‐ dwelling, well functioning elderly (aged 70 to 79, blacks and whites, males and females) selected from 2,732 participants enrolled in the Health, Aging, and Body Composition Study (Health ABC). The periodontal evaluations occurred over years 2 and 3 of the study and included four indices of periodontal health: plaque index (PI), gingival index (GI), probing depth (PD), and loss of attachment (LOA). The pulmonary evaluation took place in year 1: conducted according to American Thoracic Society criteria, based on the forced expiratory volume/forced vital capacity (FEV1/FVC) ratio and then using the percent of predicted FEV1 to categorize severity.Results: GI (P = 0.023) and LOA (P = 0.009) were significantly better in participants with normal pulmonary function compared to those with airway obstruction after adjusting for age, race, gender, and field center. When stratified by smoking status and after adjusting for age, race, gender, center, and pack‐years, there was a significant association between periodontal health and airway obstruction in former smokers. Within this group, those with normal pulmonary function had significantly better GI (P = 0.036) and LOA (P = 0.0003) scores than those with airway obstruction. All periodontal indices were elevated in smokers regardless of pulmonary status; however, the current smoker group was too small to detect a periodontitis effect.Conclusion: While the present cross‐sectional study cannot provide direct inference of cause and effect, it does reveal a significant association between periodontal disease and airway obstruction, particularly in former smokers.
Cadmium, Copper, Nickel, and Zinc Availability in a Biosolids‐Amended Piedmont Soil Years after Application
Authors: Sukkariyah Beshr F. , Evanylo Gregory , Zelazny Lucian , Chaney Rufus L. 
Published: November 2005

ABSTRACTConcerns over the possible increase in phytoavailability of biosolids‐applied trace metals to plants have been raised based on the assumption that decomposition of applied organic matter would increase phytoavailability. The objectives of this study were to assess the effect of time on chemical extractability and concentration of Cd, Cu, Ni, and Zn in plants on plots established by a single application of biosolids with high trace metals content in 1984. Biosolids were applied to 1.5 by 2.3 m confined plots of a Davidson clay loam (clayey, kaolinitic, thermic Rhodic Kandiudults) at 0, 42, 84, 126, 168, and 210 Mg ha−1 The highest biosolids application supplied 4.5, 760, 43, and 620 kg ha−1 of Cd, Cu, Ni, and Zn, respectively. Radish (Raphanus sativus L.), romaine lettuce (Lactuca sativa L. varlongifolia), and barley (Hordeum vulgare L.) were planted at the site for 3 consecutive years, 17 to 19 yr after biosolids application. Extractable Cd, Cu, Ni, and Zn (as measured by DTPA, CaCl2, and Mehlich‐1) were determined on 15‐cm depth samples from each plot. The DTPA‐extractable Cu and Zn decreased by 58 and 42%, respectively, 17 yr after application despite a significant reduction in organic matter content. Biosolids treatments had no significant effect on crop yield. Plant tissue metal concentrations increased with biosolids rate but were within the normal range of these crops. Trace metal concentrations in plants generally correlated well with the concentrations extracted from soil with DTPA, CaCl2, and Mehlich‐1. Metal concentrations in plant tissue exhibited a plateau response in most cases. The uptake coefficient values generated for the different crops were in agreement with the values set by the Part 503 Rule.
Mycorrhizae Increase Arsenic Uptake by the Hyperaccumulator Chinese Brake Fern (Pteris vittataL.)
Authors: Al Agely Abid , Sylvia David M. , Ma Lena Q. 
Published: November 2005

ABSTRACTChinese brake fern (Pteris vittataL.) is a hyperaccumulator of arsenic (As) that grows naturally on soils in the southern United States. It is reasonable to expect that mycorrhizal symbiosis may be involved in As uptake by this fern. This is because arbuscular mycorrhizal (AM) fungi have a well‐documented role in increasing plant phosphorus (P) uptake, P and As have similar chemical properties, and ferns are known to be colonized by AM fungi. We conducted a factorial greenhouse experiment with three levels of As (0, 50, and 100 mg kg−1) and P (0, 25, and 50 mg kg−1) and with and without Chinese brake fern colonized by a community of AM fungi from an As‐contaminated site. We found that the AM fungi not only tolerated As amendment, but their presence increased frond dry mass at the highest As application rate. Furthermore, the AM fungi increased As uptake across a range of P levels, while P uptake was generally increased only when there was no As amendment. These data indicate that AM fungi have an important role in arsenic accumulation by Chinese brake fern. Therefore, to effectively phytoremediate As‐contaminated soils, the mycorrhizal status of ferns needs to be taken into account.
Freeze–Thaw Effects on Phosphorus Loss in Runoff from Manured and Catch‐Cropped Soils
Authors: Bechmann Marianne E. , Kleinman Peter J. A. , Sharpley Andrew N. , Saporito Lou S. 
Published: November 2005

ABSTRACTConcern over nonpoint source P losses from agricultural lands to surface waters in frigid climates has focused attention on the role of freezing and thawing on P loss from catch crops (cover crops). This study evaluated the effect of freezing and thawing on the fate of P in bare soils, soils mixed with dairy manure, and soils with an established catch crop of annual ryegrass (Lolium multiflorum L.). Experiments were conducted to evaluate changes in P runoff from packed soil boxes (100 by 20 by 5 cm) and P leaching from intact soil columns (30 cm deep). Before freezing and thawing, total P (TP) in runoff from catch‐cropped soils was lower than from manured and bare soils due to lower erosion. Repeated freezing and thawing significantly increased water‐extractable P (WEP) from catch crop biomass and resulted in significantly elevated concentrations of dissolved P in runoff (9.7 mg L−1) compared with manured (0.18 mg L−1) and bare soils (0.14 mg L−1). Catch crop WEP was strongly correlated with the number of freeze–thaw cycles. Freezing and thawing did not change the WEP of soils mixed with manures, nor were differences observed in subsurface losses of P between catch‐cropped and bare soils before or after manure application. This study illustrates the trade‐offs of establishing catch crops in frigid climates, which can enhance P uptake by biomass and reduce erosion potential but increase dissolved P runoff.
Root Exudation, Phosphorus Acquisition, and Microbial Diversity in the Rhizosphere of White Lupine as Affected by Phosphorus Supply and Atmospheric Carbon Dioxide Concentration
Authors: Wasaki Jun , Rothe Annett , Kania Angelika , Neumann Günter , Römheld Volker , Shinano Takuro , Osaki Mitsuru , Kandeler Ellen 
Published: November 2005

ABSTRACTWhite lupine (Lupinus albus L.) was used as a phosphorus (P)‐efficient model plant to study the effects of elevated atmospheric CO2 concentrations on (i) P acquisition, (ii) the related alterations in root development and rhizosphere chemistry, and (iii) the functional and structural diversity of rhizosphere microbial communities, on a P‐deficient calcareous subsoil with and without soluble P fertilization. In both +P (80 mg P kg−1) and −P treatments (no added P), elevated CO2 (800 μmol mol−1) increased shoot biomass production by 20 to 35% and accelerated the development of cluster roots, which exhibit important functions in chemical mobilization of sparingly soluble soil P sources. Accordingly, cluster root formation was stimulated in plants without P application by 140 and 60% for ambient and elevated CO2 treatments, respectively. Intense accumulation of citrate and increased activities of acid and alkaline phosphatases, but also of chitinase, in the rhizosphere were mainly confined to later stages of cluster root development in −P treatments. Regardless of atmospheric CO2 concentrations, there was no significant effect on accumulation of citrate or on selected enzyme activities of C, N, and P cycles in the rhizosphere of individual root clusters. Discriminant analysis of selected enzyme activities revealed that mainly phosphatase and chitinase contributed to the experimental variance (81.3%) of the data. Phosphatase and chitinase activities in the rhizosphere might be dominated by the secretion from cluster roots rather than by microbial activity. Alterations in rhizosphere bacterial communities analyzed by denaturing gradient gel electrophoresis (DGGE) were related with the intense changes in root secretory activity observed during cluster root development but not with elevated CO2 concentrations.
Phosphorus Losses from Agricultural Areas in River Basins
Authors: Kronvang B. , Bechmann M. , Lundekvam H. , Behrendt H. , Rubæk G. H. , Schoumans O. F. , Syversen N. , Andersen H. E. , Hoffmann C. C. 
Published: November 2005

ABSTRACTIn this paper we show the quantitative and relative importance of phosphorus (P) losses from agricultural areas within European river basins and demonstrate the importance of P pathways, linking agricultural source areas to surface water at different scales. Agricultural P losses are increasingly important for the P concentration in most European rivers, lakes, and estuaries, even though the quantity of P lost from agricultural areas in European catchments varies at least one order of magnitude (<0.2 kg P ha−1 to >2.1 kg P ha−1). We focus on the importance of P for the implementation of the EU Water Framework Directive and discuss the benefits, uncertainties, and side effects of the different targeted mitigation measures that can be adopted to combat P losses from agricultural areas in river basins. Experimental evidence of the effects of some of the main targeted mitigation measures hitherto implemented is demonstrated, including: (i) soil tillage changes, (ii) treatment of soils near ditches and streams with iron to reduce P transport from source areas to surface waters, (iii) establishment of buffer zones for retaining P from surface runoff, (iv) restoration of river–floodplain systems to allow natural inundation of riparian areas and deposition of P, and (v) inundation of riparian areas with tile drainage water for P retention. Furthermore, we show how river basin managers can map and analyze the extent and importance of P risk areas, exemplified by four catchments differing in size in Norway, Denmark, and the Netherlands. Finally, we discuss the factors and mechanisms that may delay and/or counteract the responses of mitigation measures for combating P losses from agricultural areas when monitored at the catchment scale.