bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative Study of Methods for Estimating Bioavailable Particulate Phosphorus
Authors: Young TC , De Pinto JV , Hughes BJ
Published: December 2008

A group of chemical and biological procedures for estimating the biologically available phosphorus (BAP) in sediments, representing methods currently used for research around the Great Lakes, were compared among twelve widely different samples of particulate matter from the lower Great Lakes region. The procedures, including one biological and five chemical methods, extracted widely differing amounts of phosphorus from the sediments. Among the procedures, however, the results were highly correlated, indicating the potential for making valid conversions among the estimates, at least for most samples. Analysis of samples held in storage for several years, however, gave results by some extraction procedures that seemed abnormal. Phosphorus extracted by the procedures of Armstrong et al. [1] and Baker [2] correlated most closely with bioassay results, while that extracted by the procedure of De Pinto et al. [3] most closely approximated amounts of phosphorus taken up by algae during bioassays.
Characterization of Trace Metal Associations with Polluted Marine Sediments by Selective Extractions
Authors: Boothman WS
Published: December 2008

The biological availability and geochemical fate of toxic metals in materials disposed of in the marine environment are dependent in part on the chemical forms in which the metals are present. In order to characterize the associations of trace metals with particulate matter in polluted marine sediments, samples of dredged materials removed from Black Rock Harbor, CT and sediments from the disposal site in Long Island Sound collected subsequent to disposal have been sequentially extracted with a series of solutions. The solutions correspond to a range of conditions under which different sediment phases can be solubilized, and operationally define four sediment fractions: exchangeable, weak acid soluble, oxidizable, and strong acid soluble.

In the dredge material, cadmium, copper, and chromium are all predominantly associated with the oxidizable fraction, that is, with sulfides and organic matter, while lead is found primarily in the residual, strong acid soluble fraction. Data from sediment samples collected at the disposal site indicate oxidation of the surface sediments during the warmer months and result in the redistribution of cadmium and, to a lesser extent, copper to the more labile exchangeable and weak acid soluble fractions. Chromium and lead show little evidence of alterations in the binding of those metals to sediments.
An Examination of Methods for the Concentration of Suspended Sediment for Direct Metal Analysis
Authors: Horowitz AJ
Published: December 2008

Suspended sediment plays an important role in the transport and geochemical cycling of aquatic trace metals. The sampling and subsequent analysis of suspended sediment has been used to locate ore deposits, determine water-quality trends, and identify anthropogenic pollution sources. Many laboratories and organizations determine suspended sediment-trace metal concentrations by the method of difference. However, this procedure may lack sufficient sensitivity to accurately and precisely determine suspended sediment metal levels when either metal or suspended sediment concentrations are low. Many of the difficulties associated with the method of difference can be eliminated or minimized by a direct analysis of suspended sediment. The classical procedure for concentrating (dewatering) suspended sediment entails in-line filtration using preweighed 0.45-µm membrane filters; subsequent analysis entails the digestion of the sediment plus filter, analysis of the digestate, and the application of a blank correction for metal contributions from the filters. This procedure can be prohibitively expensive and time consuming, especially when large-scale studies with numerous sampling sites or high sampling frequencies are required. Potential alternative methods of concentration (dewatering) of suspended sediment which could be used in lieu of in-line filtration and for direct quantitation of trace metals while reducing costs were investigated. Three potential substitute procedures—batch centrifugation, settling-centrifugation, and backflush-filtration—were compared to in-line filtration, and were field and laboratory tested. Results indicate that both the batch centrifugation and the settlingcentrifugation procedures are comparable with in-line filtration, and are amenable to large-scale sampling and trace-metals analysis programs.
Use of Gas Chromatography/Mass Spectrometry to Monitor Selected Priority Pollutant Levels in Landfill Simulator Leachates
Authors: Stamm JW , Walsh JJ , Jess W , Rickabaugh JI
Published: December 2008

The U.S. Environmental Protection Agency (EPA), Wastewater Research Division, is desirous of determining the impacts of disposing municipal wastewater treatment sludge to landfills. To fulfill this research need, SCS Engineers is conducting a program to monitor environmental emissions from 28 landfill simulators located at the EPA Test and Evaluation (T&E) Facility in Cincinnati, OH. These landfill simulators contain mixtures of limes and anerobically digested sludges, and municipal solid waste. One of the major goals of the program is to document and examine the release of six priority pollutants, which have been spiked into selected test cells.

Leachate samples are analyzed by combined gas chromatography/mass spectrometry (GC/MS). Quantitation of the pollutants is accomplished using the isotope dilution technique. By adding a known amount of a labeled pollutant to a sample before extraction, correction for recovery of the pollutant can be made because the pollutant and its labeled analog exhibit the same effects from extraction, concentration, and gas chromatography. In addition, the method of gel permeation chromatography (GPC) is also employed for sample purification.

Preliminary findings indicate that pollutant release from codisposal test cells is not dissimilar from that seen in refuse-only cells. Use of the GPC technique has improved the percent recovery in the analysis of landfill simulator leachates. Obviously, further investigation is required, since true environmental impact can be seen only through long-term monitoring.
Total, Extractable, and Leachable Organic Halides in Soil and Sediments
Authors: Martin JT , Takahashi Y
Published: December 2008

The presence of total organic halides (TOX) in soils and sediments is a good indicator that the soil, and possibly the underlying aquifiers, are contaminated. Since many halogenated organics are highly toxic to human health with some being carcinogenic, and naturally occurring organic halides are very limited, their occurrence strongly indicates manmade toxic contamination.

There are two approaches to TOX analysis of soil that will be discussed in this paper. The first approach investigates a set of soil samples for total halides (TX), inorganic halides (IX), and extractable organic halides (EOX). The TX are determined by direct combustion of the soil followed by microcoulometric titration of all the halides present in the soil. The IX are determined by water extraction of the soil followed by direct injection into the titration cell. The EOX are determined by using a modified version of the method developed by Riggin et al. at Battelle Laboratories (EP Document 600/4-84-008, Appendix D). The results are then compared to see if the mass balance is true: TX − IX = EOX. The second approach investigates the leachable organic halides (LOX). The LOX is determined by extracting the soil with water and then analyzing the water for TOX by the carbon adsorption method (EPA Method 9020 in SW846).

Together, these investigations demonstrate the utility and flexibility of TOX analysis of soils and sediments.
Determination of Polychlorinated Compounds (Dioxins, Furans, and Biphenyls) by Level of Chlorination with Automated Interpretation of Mass Spectrometric Data
Authors: Alford-Stevens AL , Budde WL
Published: December 2008

A procedure has been developed to identify and measure members of three classes of chlorinated compounds by level of chlorination. These classes are polychlorinated biphenyls, chlorinated dibenzo-p-dioxins, and chlorinated dibenzofurans. A gas chromatograph (GC) equipped with a capillary column and interfaced to a computerized mass spectrometer (MS) was used. Mass spectral data were processed with special software that provides automated determinations. With each class of compounds, MS detector response was calibrated using one isomer to represent all compounds at each level of chlorination. A concentration was measured for each isomer group, and total compound class concentration was obtained by summing isomer group concentrations. Results obtained with the software were compared with results obtained when an experienced analyst used standard GC/MS data system software to process the same mass spectral data. Automated procedures produced results that were as reliable and accurate as those produced with tedious, labor-intensive human interpretation and computation.
Perspective on Risk of Waterborne Enteric Virus Infections
Authors: Wellings FM
Published: December 2008

A valid perspective on the risk of waterborne enteric virus infections related to land disposal of sludge must incorporate various parameters. It is not enough to accept at face value the predominantly negative findings from the relatively few scientific studies that have purportedly been done to determine the fate of viruses introduced into the environment with the deposition of sludge. Rather, it is incumbent upon interested parties, whether they are regulatory or scientific, to evaluate the whole through a careful examination of the parts. This paper attempts to bring into focus the presently available data on four major virological issues. These are the characteristics of enteric viruses which enable them to survive wastewater treatment processes, problems associated with the accumulation and interpretation of data related to viral contamination of groundwater by sludge disposal practices, problems associated with transfer to the real world of data derived from laboratory-seeded experiments, and problems related to the establishment of the role of enteric viruses in waterborne disease outbreaks. Present data are insufficient for establishing the quantitative risk of waterborne disease because of the land disposal of sludge. However, there is some probability of groundwater contamination sufficient to warrant a cautious approach to land disposal of sludge.
Round Robin Testing of Methods for the Recovery of Human Enteroviruses from Wastewater Sludges and Sewage Amended Soils—ASTM Consensus Standards Development
Authors: Schaub SA
Published: December 2008

The American Society for Testing and Materials Task Group on Standards Development for Virus-in-Solids (ASTM D19:24:04) has been engaged in the selection of enterovirus recovery methods for sewage sludges and sewage amended soils. Preliminary laboratory screening studies and specific selection criteria were used to identify methods to undergo extensive roundrobin comparative methods testing and subsequent standards selection.

Virus-in-sludge recovery methods were evaluated first. The sonication-extraction and the low-in-pH-aluminum chloride (AlCl3) methods were selected for round-robin testing. Eight laboratories participated in this evaluation by using five typical sludges and their indigenous enterovirus populations. Although the low pH-AlCl3 method provided a somewhat higher ratio of recovery efficiency in individual tests, there was no statistically significant difference between the methods, and their precisions were essentially identical. Therefore, both were recommended as ASTM standard methods.

Virus-in-soil recovery methods are currently being evaluated in round-robin tests by nine laboratories using four typical soil types seeded with enterovirus concentrates from raw sewage. The selection criteria and round-robin test protocols are very similar to those used in the sludge methods evaluation procedure.
Recovery of Naturally Occurring Rotaviruses during Sewage Treatment
Authors: Chalapati Rao V , Metcalf TG , Melnick JL
Published: December 2008

Human enteric viruses occur in large numbers in sludges and in aquatic sediments from polluted waters. Of these agents, rotaviruses are often involved in water- and food-borne outbreaks. They represent health hazards of undetermined magnitude. Virus levels in sludges may be reduced, but the viruses are not eliminated by aerobic and anaerobic treatment. A study of the removal of indigenous rotaviruses during the primary settling and activated sludge treatment of raw sewage was conducted for a period of 8 months in a Houston, TX, plant treating 5.55 million L per day. An average rotavirus reduction of 44 to 55% was obtained by primary settling and a reduction of 93 to 99% was achieved in the final chlorinated effluents. Composite sampling at 1-h intervals over a 24-h period indicated average removals of 85%—a measure much more accurate than the misleading average of 6% indicated by one series of grab samples of raw sewage and effluent collected simultaneously. Quantification of rotaviruses was based on counts of immunofluorescent foci 24 h after addition of sample concentrates to coverslip cultures of fetal rhesus monkey kidney cells. Rotavirus quantities ranged from 40 to 510 per liter of raw sewage and from 0 to 25 per liter in the final chlorinated effluent.
Mutagenic Potential of Municipal Sewage Sludge and Sludge Amended Soil
Authors: Donnelly KC , Brown KW , Chisum CP
Published: December 2008

Twelve municipal wastewater treatment plant sludges were collected and extracted by sequential extraction with methylene chloride and methanol on a Soxhlet apparatus. Each of three sludge fractions, methylene chloride, methanol, and a combined fraction (36 fractions total) was tested in the Salmonella/microsome assay. Only one of the sludge fractions induced a positive response in the absence of metabolic activation, and twelve fractions induced a doubling of revertant colonies at two or more consecutive dose levels with activation. The maximum mutagenic response observed with strain TA98 in a methylene chloride fraction was 120 net revertants at a dose level of 10 mg of extract per plate. The maximum response induced by the methanol and combined fractions was 89 net revertants, induced by a municipal sludge with 20% industrial contribution, and 61 net revertants, induced by a municipal sludge with 19% industrial contribution, respectively, both tested with strain TA98 at a dose level of 5 mg of extract per plate. These results indicate that there will be substantial differences in the mutagenic potential of municipal sludges from a single source and from different sources. The results of a land application study using one of these sludges indicates that some of these mutagenic compounds may be persistent in the soil.
Biochemical Characterization of Estuarine Benthic Microbial Communities for Use in Assessing Pollution Impacts
Authors: Schropp SJ , Lewis FG , Eubanks W , Carman KR , White DC
Published: December 2008

Monitoring the benthic microbial community offers a means of assessing biological changes in response to pollutants at the base of the estuarine food web. Traditional methods of microbial community analysis are inadequate because they require removal of the microorganisms from their habitat for culture on laboratory media, resulting in bias. Biochemical techniques, however, allow the microbial community structure to be analyzed without removing the microorganisms from their habitat. We have used analyses of phospholipid fatty acids (PLFA) to characterize benthic microbial community structure in Biscayne and Pensacola Bays, FL, and to relate changes in microbial community structure to sources of metal pollution. Sediment samples were obtained from clean and contaminated areas of each bay system. PLFA were analyzed by capillary gas chromatography after modified Bligh-Dyer extraction and silicic acid column chromatography. Principal components analysis was used to distinguish geographic areas, and stations within these areas, from one another based on either geochemical or microbial PLFA data. Canonical correlation was used to construct a linear relationship between metal concentrations and microbial PLFA characteristics, but was confounded by sediment grain size. Polluted stations were generally characterized by high metal concentrations, fine-grain sediments, high lipid phosphate, high trans/cis fatty acid ratios, high bacterial PLFA, and low eucaryotic PLFA.
Variability of the Acute Toxicity of Drilling Fluids to Mysids (Mysidopsis bahia)
Authors: Parrish PR , Duke TW
Published: December 2008

Numerous factors affect the acute toxicity of drilling fluids (muds) to mysids (Mysidopsis bahia). The source, composition, and age of drilling fluid sample; preparation of test material; condition of test animals; and skill and experience of the people conducting the tests can influence test results. Despite these confounding factors, our intralaboratory variation of median lethal concentrations (96-h LC50s) for six tests with a laboratory-prepared generic drilling fluid was within a factor of two; interlaboratory variation for seven commercial laboratories that tested the same generic drilling fluid was within a factor of four, the same as reported in the literature for acute toxicity tests with single chemicals. The presence of petroleum hydrocarbons in drilling fluids greatly increases toxicity and, because toxic, volatile fractions may be lost, the variability of results from tests with petroleum hydrocarbon-contaminated drilling fluids may be greater than that stated above.
Toxicity Testing of Dredged Materials Using Multiple-Species Microcosms
Authors: Alden RW , Butt AJ
Published: December 2008

Microcosm experiments were conducted to evaluate the relative toxicity of sediments taken from dredge sites in the Port of Hampton Roads, VA. The multiple species microcosm were designed to allow natural assemblages of zooplankton and benthos to be exposed to dredged materials under more realistic conditions than achieved in bioassays. Changes in community structure and body burdens of contaminants were monitored in the microcosms following “dumps” of the sediments.

The biological effects of exposure to dredged materials under the microcosm conditions were subtle. Zooplankton community structure was only affected by treatments involving sediments known to be most contaminated with polynuclear aromatic hydrocarbons and metals. Likewise, statistically significant changes were observed in the composition of benthic communities exposed to the most contaminated sediments. Motile forms appeared to have migrated from the contaminated sediments in various degrees while more sedentary species displayed mortalities relative to the controls.

Body burden studies indicated that experimental animals did not accumulate significant concentrations of metals or chlorinated hydrocarbons in any of the treatments. However, biota exposed to the contaminated sediments did accumulate certain of the polynuclear aromatic hydrocarbons known to be major pollutants in the port.
Analytical Methods Necessary to Implement Risk-Based Criteria for Chemicals in Municipal Sludge
Authors: Bruins RJF , Fradkin L , Stara JF , Peirano WB , Molak V , Lomnitz E
Published: December 2008

The Ambient Water Quality Criteria that were promulgated by the U.S. Environmental Protection Agency (EPA) in 1980 included water concentration levels which, for many pollutants, were so low as to be unmeasurable by standard analytical methods. Criteria for controlling toxics in municipal sludge would likely pose similar problems of sampling and analysis. Risk assessment methodologies recently developed by the U.S. EPA provide criteria derivation procedures for each of the following sludge management practices: land application (including distribution and marketing), landfilling, incineration, and ocean disposal. These methodologies recommend that numerical limits on toxicant concentrations in sludge, or on rates of toxicant disposal, should be used to minimize risk to human health and the environment. Implementation of these numerical criteria would require refinement of sampling and analytical techniques for sludges, and various types of field validation studies would be needed to ensure that the criteria are appropriately protective.
Microbiological Risk Assessment for Land Application of Municipal Sludge
Authors: Scarpino PV , Fradkin L , Clark CS , Kowal NE , Lomnitz E , Baseheart M , Peterson JM , Ward RL , Hesford M
Published: December 2008

Each major option for the disposal/reuse of municipal sludges poses potential risks to human health or the environment because of the microbial contaminants in sludge. Therefore, risk assessment methodology appropriate for pathogen risk evaluation for land application and distribution and marketing (D&M) options was developed. A computer model was designed to aid in sludge management by comparing the risks of alternatives as sludge is applied to cropland and grazed pasture as a fertilizer and/or soil conditioner. The model integrates microbial dose-response information with the number of pathogens likely to be present in exposure pathways. Interpretations from risk assessment model outputs were made.
Iodine levels and thyroid hormones in healthy pregnant women and birth weight of their offspring
Authors: Alvarez-Pedrerol M , Guxens M , Mendez M , Canet Y , Martorell R , Espada M , Plana E , Rebagliato M , Sunyer J
Published: December 2008

Introduction

The fetus is most vulnerable to severe iodine deficiency and hypothyroidism during pregnancy. The effects of mild iodine deficiency and subclinical hypothyroidism are poorly known. The present study assesses the association between thyroid hormones (TH)s and urinary iodine concentration (UIC) in healthy pregnant women and the birth weight of their children.

Methods

About 657 pregnant women were recruited in Sabadell and followed until delivery. The association between THs during the first trimester, UIC during the first and third trimesters, and birth weight was studied in 557, 251, and 528 mother–newborn pairs respectively, using linear and logistic regression models adjusted for potential confounders. Only 239 women had all the data available (thyroid function and UIC at the first and third trimesters). Six percent of newborns were classified as small for gestational age (SGA).

Results

The median UIC was 95 and 104 μg/l during the first and third trimesters respectively. Women with the third trimester UICs between 100 and 149 μg/l had lower risk of having an SGA newborn than women with UICs below 50 μg/l (adjusted OR (95%CI): 0.15 (0.03–0.76). There was no significant reduction in SGA among mothers with higher UICs. Lower free thyroxine and higher TSH levels during the first trimester were not associated with birth weight or SGA. Nevertheless, the analyses were repeated including only those women with all the data available, and high TSH levels became statistically significantly associated with lower birth weight and higher risk of SGA.

Conclusions

The present study suggests that iodine status during pregnancy may be related to prenatal growth in healthy women.
The skeletal phenotypes of TRα and TRβ mutant mice
Authors: Bassett J H Duncan , Williams Graham R
Published: December 2008

Analysis of mice harbouring deletions or mutations of T3 receptor α (TRα) and β (TRβ) have clarified the complex relationship between central and peripheral thyroid status and emphasised the essential but contrasting roles of T3 in skeletal development and adult bone. These studies indicate that TRα1 is the predominant TR expressed in bone and that T3 exerts anabolic actions during growth but catabolic actions in the adult skeleton. Examination of key skeletal regulatory pathways in TR mutant mice has identified GH, IGF-1 and fibroblast growth factor signalling and the Indian hedgehog/parathyroid hormone-related peptide feedback loop as major targets of T3 action in chondrocytes and osteoblasts. Nevertheless, although increased osteoclastic resorption is a major feature of thyrotoxic bone loss and altered osteoclast activity is central to the skeletal phenotype of TR mutant mice, it remains unclear whether T3 has direct actions in osteoclasts. Detailed future analysis of the molecular mechanisms of T3 action in bone will enhance our understanding of this emerging field and has the potential to identify novel strategies for the prevention and treatment of osteoporosis.
Patterns of fish community structure in a long-term watershed-scale study to address the aquatic ecosystem effects of pulp and paper mill discharges in four us receiving streams
Authors: Flinders Camille A , Ragsdale Renee L , Hall Timothy J
Published: December 2008

Physiological changes have been seen in individual fish exposed to pulp and paper mill effluent (PPME), but it is unclear whether community-level changes are seen in fish in PPME receiving waters. We conducted a study of 4 PPME receiving streams (Codorus Creek, PA, USA), the Leaf River (Forrest and Perry Counties, MS, USA), and the McKenzie and Willamette rivers (Lane County, OR, USA) over 9 y to assess temporal patterns in the type and relative abundance of fish species and measures of community structure and function related to PPME discharge. We used boat and backpack electrofishing to sample large- and small-bodied fish from the McKenzie and Willamette rivers, boat electrofishing to sample large-bodied fish from the Leaf River, and backpack electrofishing to sample the entire fish community from Codorus Creek. Study streams represented different ecoregions, warm- and coldwater systems, gradients of PPME concentration (<1%-33%), and mill process types. Bray-Curtis similarity and nonmetric multidimensional scaling showed high variation in fish communities across sites, seasons, and years. Significant site differences in fish communities were seen in most streams and community types, but distinct separation of sites was seen only in Codorus Creek and unrelated to PPME discharge. No seasonal differences were seen in fish community structure in any stream, with only weak annual patterns in large-bodied fish in the Leaf River and small-bodied fish in the McKenzie River. General linear models were used to examine spatial and temporal variation in fish metric response (abundance, species richness, Simpson's diversity, % dominant species, standing crop, % DELT, % intolerant, % omnivore, % piscivore). Significant site differences in metric response were largely limited to Codorus Creek and unrelated to PPME. Significant reductions of % dominant taxa of small-bodied fish and % large-bodied piscivores were also observed downstream of the PPME discharge on the McKenzie River relative to upstream sites. Seasonal changes in fish metric response were rare, and changes with year were variable. The relationship between fish community structure and water quality variables (pH, color, conductivity, total phosphorus, total nitrogen) was weak in all streams for all community types. The results of this study show that PPME exposure has little effect on fish communities in these streams and aid in addressing management strategies. The high spatial and temporal variability reiterate the importance of long-term studies to elucidate patterns in receiving waters.
A long-term, multitrophic level study to assess pulp and paper mill effluent effects on aquatic communities in four us receiving waters: Lessons learned
Authors: Hall Timothy J , Fisher Robert P , Rodgers John H , Minshall G Wayne , Landis Wayne G , Kovacs Tibor , Firth Barry K , Dubé Monique G , Flinders Camille A , Deardorff Thomas L , Borton Dennis L
Published: December 2008

Lessons learned from the development, implementation, and initial 8 y of study findings from a long-term study to assess the effects of pulp and paper mill effluents on receiving waters are summarized as a conclusion to a series of articles (this issue) on study findings. The study, based on industry-defined information needs, was developed via a science-based experimental design into a long-term (>10 y) watershed-scale monitoring program that integrated in-stream population/community assessment, laboratory chronic bioassays, and fathead minnow full life-cycle assays as well as water quality and effluent quality monitoring and habitat assessment in addressing the presence of effluent effects. The 4 study streams (Codorus Creek, PA; Leaf River, MS; and the McKenzie and Willamette rivers, OR) represented both bleached and unbleached kraft mill processes and effluent concentrations that ranged from near typical for the United States (0.4%) to very high (Codorus Creek = 32%). Following 8 y of monitoring, the weight of evidence suggests an absence of biological differences at stations downstream of the mill discharges for periphyton or macroinvertebrates and, with the exception of 1 of 9 large-bodied fish and 1 of 7 small-bodied fish community structure metrics for 1 river (McKenzie), an absence of differences for fish communities. Laboratory bioassay and fathead minnow full-life cycle tests supported a substantial “margin of safety” in that, depending on the effluent, adverse responses did not occur until effluent concentrations were from 2 times to more than 150 times in-stream concentrations. The incorporation of a watershed spatial scale illustrated that each sample site tended to be unique over the 28 to 50 km monitored segments with respect to habitat and that knowledge of these variables permitted accurate evaluations of effluent effects. Similarly, the multiyear study framework provided information regarding the natural seasonal and year-to-year variability in fish communities and consequently a better understanding of how potential effluent effects signals could be expressed within this variability. The study incorporated an adaptive management strategy that provided for study design and monitoring modifications over time as a way of benefiting from practical experience and knowledge gained through time and to optimize the use of study resources. Results from this initial 8 y of monitoring, to our knowledge, represent the longest-known population/community-level assessment of the in-stream effects of pulp and paper mill effluents. Beyond the lessons learned with respect to effluent effects are those related to the design and conduct of long-term watershed-scale studies that may be of use to others in developing watershed assessment or management programs.
Lead in sarbaz river basin sediments, sistan and baluchestan, iran
Authors: Varkouhi Shahab
Published: December 2008

Streambed-sediment samples were collected in the Sarbaz River Basin in Sistan and Baluchestan Province, east of Iran, to characterize the occurrence and distribution of lead in natural and anthropogenic sites of the basin. During June and July 2008, stream sediment was collected at 30 sites, and the samples were analyzed for lead. Sites sampled represented agricultural, mining, mixed, rangeland, recreation, and residential land uses and background conditions. Lead was detected in all collected stream-sediment samples of the basin. Most of the lead concentration was associated with the smaller part of the 2 grain-size fractions: 2000 to 43 μm and <43 μm. The range in concentrations of lead at urban/rural sites generally was higher than the range of concentrations at nonurban/rural sites. Sediment from 2 distinctly different rock types in urban/rural areas were not significantly different (t = 0.1330, p = 0.8955) for concentrations of lead. Concentrations of lead were not significantly different (t = 0.0845, p = 0.6865) between main-stem sites and tributary sites. Concentrations of lead exceeded established sediment-quality guidelines for adverse effects on aquatic biota at most of the urban/rural sites in the study area.
Comparison of Clinical, Periapical Radiograph, and Cone‐Beam Volume Tomography Measurement Techniques for Assessing Bone Level Changes Following Regenerative Periodontal Therapy
Authors: Grimard Brently A. , Hoidal Matt J. , Mills Michael P. , Mellonig James T. , Nummikoski Pirkka V. , Mealey Brian L.
Published: December 2008

Background: Intraoral radiographs (IRs) provide a two‐dimensional view of osseous structures, whereas cone‐beam volumetric tomography (CBVT) images are viewable in three dimensions. The aim of this investigation was to compare the measurements from digital IR and CBVT images to direct surgical measurements for the evaluation of regenerative treatment outcomes.

Methods: Digital IR and CBVT images were taken prior to initial bone grafting and at the 6‐month reentry surgery for 35 intrabony defects. After defect debridement, direct bony defect measurements were made with a periodontal probe. These same measurements were made on the IR and CBVT images and then compared to the direct surgical values.

Results: CBVT correlated strongly with surgical measurements (r = 0.89 to 0.95), whereas IRs correlated less favorably (r = 0.53 to 0.67). IR measurements were significantly less accurate compared to CBVT for all parameters investigated and underestimated surgical measurements from 0.6 ± 2.3 mm to 1.5 ± 2.3 mm. No significant difference for the distance from the cemento‐enamel junction (CEJ) to the alveolar crest (P = 0.66 for initial measurement and P = 0.92 for reentry), defect fill (P = 0.14), or defect resolution (P = 0.09) was seen between CBVT and surgical measurements; however, there was a significant difference for the distance from the CEJ to the base of the defect, with CBVT measurements underestimating the surgical measurements by 0.5 ± 1.1 mm for reentry (P <0.01) and 0.9 ± 0.8 mm for the initial measurement (P <0.01).

Conclusions: Overall, compared to direct surgical measurements, CBVT was significantly more precise and accurate than IRs. If supported by further research, CBVT may obviate surgical reentry as a technique for assessing regenerative therapy outcomes.
Macrophage Inflammatory Protein‐1α: A Salivary Biomarker of Bone Loss in a Longitudinal Cohort Study of Children at Risk for Aggressive Periodontal Disease?
Authors: Fine Daniel H. , Markowitz Kenneth , Furgang David , Fairlie Karen , Ferrandiz Javier , Nasri Cebile , McKiernan Marie , Donnelly Robert , Gunsolley John
Published: December 2008

Background: Periodontitis develops in a time‐dependent manner. Cross‐sectional studies document one moment in time but fail to capture the progressive nature of disease. Radiographic measures of bone loss are relatively insensitive but are reliable markers of irreversible disease. Longitudinal studies are needed to identify biomarkers that can precede radiographic evidence of bone loss and, thus, mark the period prior to clinical evidence of irreversible disease. A longitudinal study of students susceptible to localized aggressive periodontitis (LAgP) was conducted to evaluate chemokines/cytokines found in saliva derived from periodontally healthy children who subsequently developed alveolar bone loss.

Methods: Students were screened, sampled for Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans [Aa]), and divided into a cohort of Aa+ and Aa− students. Ninety‐six periodontally healthy Aa+ and Aa− students were recalled every 6 to 9 months following screening. Examinations, saliva collections, and radiographs were performed. After seven students developed bone loss, the levels of 21 cytokines were assessed and matched to saliva from seven Aa+ and seven Aa− students who remained healthy for ≥1 year. Subsequently, saliva from an additional 27 students who remained healthy was analyzed.

Results: Nineteen cytokines were not detected or were detected at low levels. Macrophage inflammatory protein (MIP)‐1α was elevated 50‐fold in seven Aa+ students who developed disease 6 to 9 months prior to radiographic detection of bone loss compared to levels in 21 Aa+ and 20 Aa− students who remained healthy (P <0.001). Interleukin (IL)‐1β was also elevated (P = 0.01). MIP‐1α had a specificity of 96.8% and a sensitivity of 100%, whereas IL‐1β showed 90.3% specificity and 85.7% sensitivity relative to bone loss. MIP‐1α levels were also related to increasing probing depth and the number of pockets >6 mm.

Conclusion: The superior sensitivity and specificity of MIP‐1α, which correlated well with probing depths and the onset of bone loss, suggested that it could be used as an early biomarker for LAgP.
Indoleamine 2,3‐Dioxygenase Expression and Regulation in Chronic Periodontitis
Authors: Nisapakultorn Kanokwan , Makrudthong Jittima , Sa‐Ard‐Iam Noppadol , Rerkyen Pimprapa , Mahanonda Rangsini , Takikawa Osamu
Published: December 2008

Background: Indoleamine 2,3‐dioxygenase (IDO) is an intracellular tryptophan‐oxidizing enzyme with immunosuppressive characteristics. Its expression and regulation in periodontal tissues are unknown. The aim of this study was to determine IDO expression in healthy gingiva and chronic periodontitis lesions. In addition, the effect of inflammatory cytokines and bacterial products on the expression and activity of DOI in human gingival fibroblasts (HGFs) was assessed.

Methods: Human gingival tissue samples were obtained from patients who underwent periodontal surgery. IDO expression in healthy gingiva and periodontitis lesions was determined by immunohistochemistry. HGF cells were treated with interferon‐gamma (IFN‐γ), interleukin (IL)‐1β, tumor necrosis factor‐alpha (TNF‐α), and lipopolysaccharides from Porphyromonas gingivalis (PgLPS). IDO mRNA expression was determined by reverse transcription‐polymerase chain reaction. The IDO enzymatic activity was determined by measuring the kynurenine level using a colorimetric method.

Results: In gingival tissues, IDO expression was detected in epithelial cells, fibroblasts, endothelial cells, and inflammatory mononuclear cells. IDO expression was higher in periodontitis lesions than in healthy gingiva. HGFs did not constitutively express IDO. IFN‐γ strongly induced IDO expression and activity in HGFs, in a dose‐dependent manner. IL‐1β, TNF‐α, and PgLPS were also able to induce IDO expression in HGF cells. IFN‐γ in combination with IL‐1β, TNF‐α, or PgLPS showed enhanced IDO expression.

Conclusions: IDO was expressed in human gingiva, and the expression was upregulated in chronic periodontitis. The increased IDO expression in periodontitis lesions may be due, in part, to the activation of HGFs by inflammatory cytokines and bacterial products.
Outcome Evaluation of Early Placed Maxillary Anterior Single‐Tooth Implants Using Objective Esthetic Criteria: A Cross‐Sectional, Retrospective Study in 45 Patients With a 2‐ to 4‐Year Follow‐Up Using Pink and White Esthetic Scores
Authors: Belser Urs C. , Grütter Linda , Vailati Francesca , Bornstein Michael M. , Weber Hans‐Peter , Buser Daniel
Published: December 2008

Background: To validate the concept of early implant placement for use in the esthetically sensitive anterior maxilla, clinical trials should ideally include objective esthetic criteria when assessing outcome parameters.

Methods: In this cross‐sectional, retrospective 2‐ to 4‐year study involving 45 patients treated with maxillary anterior single‐tooth implants according to the concept of early implant placement, a novel comprehensive index, comprising pink esthetic score and white esthetic score (PES/WES; the highest possible combined score is 20), was applied for the objective esthetic outcome assessment of anterior single‐tooth implants.

Results: All 45 anterior maxillary single‐tooth implants fulfilled strict success criteria for dental implants with regard to osseointegration, including the absence of peri‐implant radiolucency, implant mobility, suppuration, and pain. The mean total PES/WES was 14.7 ± 1.18 (range: 11 to 18). The mean total PES of 7.8 ± 0.88 (range: 6 to 9) documents favorable overall peri‐implant soft tissue conditions. The two PES variables facial mucosa curvature (1.9 ± 0.29) and facial mucosa level (1.8 ± 0.42) had the highest mean values, whereas the combination variable root convexity/soft tissue color and texture (1.2 ± 0.53) proved to be the most difficult to fully satisfy. Mean scores were 1.6 ± 0.5 for the mesial papilla and 1.3 ± 0.5 for the distal papilla. A mean value of 6.9 ± 1.47 (range: 4 to 10) was calculated for WES.

Conclusions: This study demonstrated that anterior maxillary single‐tooth replacement, according to the concept of early implant placement, is a successful and predictable treatment modality, in general, and from an esthetic point of view, in particular. The suitability of the PES/WES index for the objective outcome assessment of the esthetic dimension of anterior single‐tooth implants was confirmed. However, prospective clinical trials are needed to further validate and refine this index.
Possible role of a hydrogen peroxide-mediated mechanism in glucocorticoid receptor functional alterations associated with moderate asthma
Authors: Perisic Tatjana , Sreckovic M. , Matic Gordana
Published: December 2008

It is well known that pathogenesis and maintenance of chronic asthma is associated with alterations of glucocorticoid receptor (GR) function, and also with persistent pulmonary inflammation, the important mediators of which are reactive oxygen and nitrogen species. In this paper, we tested a hypothesis that GR functional alterations in asthma result from the action of oxidants. To that end, we conducted a series of ex vivo treatments of peripheral blood mononuclear cells (PBMCs) of healthy donors with oxidizing agents (3 morpholinosydnonimine, SIN1; S-nitroso-N-acetyl-penicillamine, SNAP; and hydrogen peroxide, H2O2) and compared the resulting GR modifications with those previously noticed in asthmatic patients. The results show that treatment of PBMCs by H2O2 provoked an increase in the level of GR protein, accompanied by a rise in the number of hormone-binding sites and a decline in the receptor's affinity for the hormone. The H2O2 induced changes, including a characteristic GR isoprotein expression pattern, were found to be very similar to the GR changes previously observed in PBMCs of moderate asthmatic patients, but not in mild asthmatics and healthy subjects. Treatment with the other oxidants applied herein produced different effects or exerted no influence on GR. Thus, this study provides preliminary data suggesting that functional alterations of the GR associated with moderate asthma may be mediated by redox mechanisms that are based on oxidative and regulatory actions of H2O2.
Effect of camphor essential oil on rat cerebral cortex activity as manifested by fractal dimension changes
Authors: Grbic G. , Culic M. , Martac L. , Sokovic M. , Spasic S. , Djokovic D.
Published: December 2008

The aim of our study was to investigate the effect of camphor essential oil on rat cerebral cortex activity by fractal analysis. Fractal dimension (FD) values of the parietal electrocortical activity were calculated before and after intra-peritoneal administration of camphor essential oil (450-675 ?l/kg) in anesthetized rats. Camphor oil induced seizure-like activity with single and multiple spiking of high amplitudes in the parietal electrocorticogram and occasional clonic limb convulsions. The FD values of cortical activity after camphor oil administration increased on the average. Only FD values of cortical ECoG sequences were lower than those before camphor oil administration.
Factors influencing germination and growth of isolated embryos of Pinus heldreichii
Authors: Stojicic Dragana , Janosevic Dusica , Uzelac Branka , Budimir Snezana
Published: December 2008

The effects of nutritional, hormonal, and physical factors on the germination and growth of isolated mature zygotic embryos of Pinus heldreichii were studied under in vitro conditions. The optimum medium for embryo germination and adequate conversion into seedlings was basal Gresshoff and Doy (1GD) medium. All tested carbohydrates at the applied concentrations stimulated embryo growth, but only 3% sucrose increased embryo germination compared to the control, while maltose had an inhibitory effect. Among the applied plant growth regulators, only gibberelic acid (GA3) had a few benefits on the development of isolated embryos into plantlets, while the others had a negative effect. Embryos cultured on an agar-solidified medium grew better and the germination percentage was higher than in a liquid medium. Light treatment did not affect embryo germination, but generally stimulated seedling growth.
Brine shrimp lethality bioassay of selected Centaurea L. species (Asteraceae)
Authors: Janackovic P. , Tesevic V. , Marin P.D. , Milosavljevic S. , Duletic-Lausevic Sonja , Janackovic Slavica , Veljic M.
Published: December 2008

Ether extracts of 15 Centaurea L. species (Asteraceae) methanol extracts of 12species, and cnicin isolated from C. derventana were tested for general bioactivity using the brine shrimp lethality test. Cnicin showed the most potent activity with LC50 0.2. Also, ether extract of C. splendens showed significant activity with LC50 7.3, as did methanol extract of C. arenaria with LC50 12.4.
Terapija manifestnog krvavljenja iz gornjeg dela digestivnog trakta uzrokovanog uzimanjem nesteroidnih antiinflamatornih lekova (NSAIL)
Authors: Bjelovic M. , Sabljak P. , Stojakov D. , Vucelic D. , Sokic-Milutinovic A. , Dunjic M.S. , Ebrahimi K. , Velickovic D. , Spica B. , Sljukic V. , Pesko P.
Published: December 2008

Introduction: The risk of upper gastrointestinal tract bleeding in the patients taking NSAID estimates 1% per year. Bleeding stops spontaneously in approximately 80% of all cases. Persistent and repeated bleeding (expecialy during the initial hospitalization ) still represent the serious clinical problem . In this group of patients, mortality rate is between 6-10 % , which in the USA counts 10- 20000 patients per year. Aim of the Study: The purpose of this review is to update the current knowledge of the use of different therapeutic strategies in patients with NSAID induced upper gastrointestinal bleeding. Results: Proton pump inhibitors (PPI) therapy is effective as a prevention of NSAID induced acidopeptic lesions, and also represents the first and best therapeutic option for the treatment of complications, such as upper gastrointestinal bleeding. In the last three decades use of early flexibile (diagnostic and therapeutic) endoscopy, agressive acidosupression (PPIs), and surgical treatment in restrictive indications, resulted in decreasing of the mortality rates from 25-35 % to 6-10%. When PPIs and flexible endoscopy are not sufficient in the control of upper gastrointestinal bleeding, use of systemic hemostatic drugs could be taken into consideration. Conclusion: Multidisciplinary approach, precise diagnostic and therapeutic criteria would probably result in better outcome of patients with active upper gastrointestinal bleeding.