bluuebunny/crossref_metadata_2025_split huggingface dataset:
Concentrations and partitioning of polychlorinated biphenyls in the surface waters of the southern Baltic Sea—seasonal effects
Authors: Smith Kilian E.C. , McLachlan Michael S. 
Published: September 2006

AbstractIn the marine environment, the partitioning of hydrophobic organic contaminants, such as polychlorinated biphenyls (PCBs), between the dissolved and suspended matter phases in the water column plays a fundamental role in determining contaminant fate (e.g., air—water exchange or food-chain uptake). Despite the pronounced seasonality in physical, chemical, and biological conditions in temperate marine ecosystems, little is known about the seasonality in organic contaminant partitioning behavior. Surface water from the western Baltic Sea was sampled regularly during an 18-month period between February 2003 and July 2004. The concentrations of seven PCB congeners were determined in the dissolved and particulate organic carbon (POC) phases. An inverse relationship was found between KPOC (i.e., the ratio between the POC-normalized PCB concentration [pg/kg POC] and the dissolved concentration [pg/L]) and temperature. The decrease in the water temperature of 20°C between summer and winter resulted in an increase in KPOC by a factor of approximately five. The POC-normalized PCB concentrations were higher in winter than in summer by a factor of 9 to 20. This reflected the higher KPOC and somewhat greater PCB concentrations in the dissolved phase, and it could have consequences for bioaccumulation of these chemicals in aquatic food webs. The results demonstrate a clear seasonality in contaminant partitioning in the temperate marine environment that should be accounted for when interpreting field data or modeling contaminant fate.
Vitellogenin 1 mRNA as an early molecular biomarker for endocrine disruption in developing zebrafish (Danio rerio)
Authors: Muncke Jane , Eggen Rik I.L. 
Published: September 2006

AbstractContemporary ecotoxicology is faced with the challenge of mechanistic understanding, a prerequisite for advanced risk assessment where acute toxicity is not the main issue. To achieve this, bioassay systems that are fast and biologically integrating and that detect a multitude of effects on a molecular level are needed. We present here the concept of such a novel test system that is built on the Danio rerio teratogenicity (DarT) assay but is extended in time and is based on testing molecular effects in the subacute toxicity range, named MolDarT. As proof of principle, we show the use of measuring vitellogenin 1 gene (vtg1) mRNA levels as a molecular marker for estrogenicity in developing zebrafish, a first module of MolDarT. Fertilized zebrafish eggs were exposed to 100, 1,000, and 2,000 ng/L (6.75 nM) 17α-ethinylestradiol (EE2), and total RNA was isolated every 24 h up to 120 h postfertilization (hpf). Abundance of vtg1 mRNA was detected using reverse transcription real-time polymerase chain reaction and normalized to β-actin mRNA abundance. Between 48 and 120 hpf, β-actin mRNA levels were constant, making this gene a suitable reference gene for normalization. A significant up-regulation of vtg1 expression was detected at 48 hpf for 1,000 and 2,000 ng/L EE2. At 72, 96, and 120 hpf, vtg1 was significantly induced for all EE2 concentrations. Expression of vtg1 was also measured in unexposed developing zebrafish. At 24 hpf and at all later time points, zebrafish embryos contained vtg1 transcripts. These findings show that vtg1 is regularly expressed in developing zebrafish and that it is inducible by EE2. We propose the use of vtg1 as molecular target for estrogenicity in the MolDarT.
Degradation of BTEX compounds under iron-reducing conditions in contaminated aquifer microcosms
Authors: Botton Sabina , Parson John R. 
Published: September 2006

Abstract
The potential for benzene, toluene, ethylbenzene, and xylenes (BTEX) degradation was investigated in microcosms inoculated with sediment and groundwater from a polluted iron-reducing aquifer. Benzene, toluene, and each of the three xylene isomers were degraded by the intrinsic microorganisms under iron-reducing conditions, but there was no removal of ethylbenzene. This work provides the first evidence for para-xylene degradation by dissimilatory iron-reducing bacteria. Microcosms adapted to benzene, toluene, or m-xylene were subsequently exposed to a different BTEX compound, which was degrade without lag phase, suggesting that the same group of bacteria could be involved in the removal of more than one BTEX compound. Furthermore, when microcosms were exposed to a mixture of BTEX, concurrent degradation of benzene and toluene, but not of meta-xylene and ethylbenzene, was observed. These results suggest that, under the influence of the plume of pollution, an iron-reducing microbial community able to degrade multiple aromatic compounds has developed.
Stimulation of reproductive growth in rainbow trout (Oncorhynchus mykiss) following exposure to treated sewage effluent
Authors: Hoger Birgit , Taylor Sean , Hitzfeld Bettina , Dietrich Daniel R. , van den Heuvel Michael R. 
Published: September 2006

AbstractRainbow trout (Oncorhynchus mykiss) were exposed to 1.5 and 15% v/v secondary treated sewage effluent for 32 weeks in flow-through mesocosms. The exposure encompassed the full period of reproductive development for rainbow trout. Trout did not show any evidence of a dose-dependent change in growth. Fish exposed to 15% effluent were the only group to show mortality (5%) over the duration of the experiment. Trout at the highest effluent concentration had significantly higher liver size than reference water fish. Both male and female trout in the 15% exposure group also exhibited significantly higher gonad weight than the reference group. In female trout, this gonad size increase could be explained by higher egg numbers. Female and male trout both displayed a significant increase in plasma 17β-estradiol levels after exposure to 15% effluent, while neither sex had dose-dependent differences in plasma testosterone. Male trout displayed elevated vitellogenin levels and reduced plasma 11-ketotestosterone concentration after exposure to 15% effluent. Chemical examination of steroidal compounds, including both estrogens and androgens, in the wastewater revealed that only estrone was detectable at a mean concentration of 4.5 ng/L. It is assumed that the effects observed in trout exposed to 15% effluent were consistent with stimulation of reproductive development due to very low levels of estrogens. Overall, long-term exposure to treated sewage effluent containing low levels of estrogen did not have significant negative implications for reproductive development in rainbow trout.
Use of the oligochaete,Lumbriculus variegatus, as a prey organism for toxicant exposure of fish through the diet
Authors: Mount David R. , Highland Terry L. , Mattson Vincent R. , Dawson Timothy D. , Lott Kevin G. , Ingersoll Christopher G. 
Published: September 2006

AbstractThe oligochaete, Lumbriculus variegatus, has several characteristics that make it desirable as a prey organism for conducting dietary exposure studies with fish. We conducted 21- and 30-d experiments with young fathead minnows (Pimephales promelas) and rainbow trout (Oncorhynchus mykiss), respectively, to determine whether a diet consisting solely of L. variegatus would support normal growth and to compare performance with standard diets (Artemia nauplii, frozen brine shrimp, or trout chow). All diets were readily accepted, and fish survived and grew well. Food conversion in both fathead minnows and rainbow trout was as high as or higher for the oligochaete diet compared with others, although this comparison is influenced by differences in ration, ingestion rate, or both. The oligochaete diet had gross nutritional analysis similar to the other diets, and meets fish nutrition guidelines for protein and essential amino acids. Methodologies and practical considerations for successfully using oligochaetes as an experimental diet are discussed. Considering their ready acceptance by fish, their apparent nutritional sufficiency, the ease of culturing large numbers, and the ease with which they can be loaded with exogenous chemicals, we believe that L. variegatus represents an excellent choice of exposure vector for exposing fish to toxicants via the diet.
Can highly hydrophobic organic substances cause aquatic baseline toxicity and can they contribute to mixture toxicity?
Authors: Mayer Philipp , Reichenberg Fredrik 
Published: September 2006

AbstractEffect concentrations for aquatic baseline toxicity generally decrease with increasing log octanol-water partition coefficient (Kow) values of up to 5 to 6, whereas less is known about the baseline toxicity of organic chemicals with log Kow values above 6. A physicochemical analysis of the dissolution process for organic chemicals was combined with reported baseline toxicity data, leading to the following conclusions. First, no absolute hydrophobicity cutoff exists for baseline toxicity at a log Kow value of 6, because aquatic baseline toxicity for fish and algae was observed for chemicals with log Kow values greater than 6.5 and with effect concentrations less than 10 μg/L. Second, the baseline toxicity of hydrophobic organic substances was exerted at a relatively constant chemical activity of 0.01 to 0.1. Finally, organic chemicals with high melting points cannot provide sufficient chemical activity to exert baseline toxicity when considered as individual, pure chemicals. However, such substances are still expected to contribute to baseline toxicity when part of a complex mixture.
Evaluating cytochrome P450 in lesser scaup (Aythya affinis) and tree swallow (Tachycineta bicolor) by monooxygenase activity and immunohistochemistry: Possible nonlethal assessment by skin immunohistochemistry
Authors: Melancon Mark J. , Kutay Amy L. , Woodin Bruce R. , Stegeman John J. 
Published: September 2006

AbstractSix-month-old lesser scaup (Aythya affinis) and nestling tree swallows (Tachycineta bicolor) were injected intraperitoneally with β-naphthoflavone (BNF) in corn oil or in vehicle alone. Liver samples were taken and stored at −80°C until microsome preparation and monooxygenase assay. Skin samples were placed in buffered formalin for subsequent immunohistochemical (IHC) analysis for cytochrome P4501A (CYP1A). Lesser scaup treated with BNF at 20 or 100 mg/kg body weight showed approximately 6- to 18-fold increases in four monooxygenases (benzyloxyresorufin-O-dealkylase, ethoxyresorufin-O-dealkylase, methoxyresorufin-O-dealkylase, and pentoxyresorufin-O-dealkylase). No IHC response was observed for CYP1A in the skin of vehicle-injected ducks, whereas in the skin from BNF-treated ducks, the positive IHC response was of similar magnitude for both dose levels of BNF. Tree swallows injected with BNF at 100 mg/kg, but not at 20 mg/kg, showed significant increases (approximately fivefold) in hepatic microsomal O-dealkylase activities. Cytochrome P4501A was undetectable by IHC response in skin from corn oil-treated swallows, but positive IHC responses were observed in the skin of one of five swallows at 20 mg/kg and four of five swallows at 100 mg/kg. Although these data do not allow construction of significant dose-response curves, the IHC responses for CYP1A in skin support the possible use of this nonlethal approach for biomonitoring contaminant exposure of birds. In addition, the CYP1A signal observed at the bases of emerging feathers suggest that these might provide less invasive sampling sites for IHC analysis of CYP1A.
New Transfer Functions for Simulation of Naturally Fractured Reservoirs With Dual-Porosity Models
Authors: Sarma Pallav , Aziz Khalid 
Published: September 2006

SummaryThis paper discusses new techniques for the modeling and simulation of naturally fractured reservoirs with dual-porosity models. Most of the existing dual-porosity models idealize matrix-fracture interaction by assuming orthogonal fracture systems (parallelepiped matrix blocks) and pseudosteady-state flow. More importantly, a direct generalization of single-phase flow equations is used to model multiphase flow, which can lead to significant inaccuracies in multiphase flow-behavior predictions. In this work, many of these existing limitations are removed in order to arrive at a transfer function more representative of real reservoirs.First, combining the differential form of the single-phase transfer function with analytical solutions of the pressure-diffusion equation, an analytical form for a shape factor for transient pressure diffusion is derived to corroborate its time dependence. Further, a pseudosteady shape factor for rhombic fracture systems is also derived and its effect on matrix-fracture mass transfer demonstrated. Also, a general numerical technique to calculate the shape factor for any arbitrary shape of the matrix block (i.e., non-orthogonal fractures) is proposed. This technique also accounts for both transient and pseudosteady-state pressure behavior. The results were verified against fine-grid single-porosity models and were found to be in excellent agreement.Second, it is shown that the current form of the transfer function used in reservoir simulators does not fully account for the main mechanisms governing multiphase flow. A complete definition of the differential form of the transfer function for two-phase flow is derived and combined with the governing equations for pressure and saturation diffusion to arrive at a modified form of the transfer function for two-phase flow. The new transfer function accurately takes into account pressure diffusion (fluid expansion) and saturation diffusion (imbibition), which are the two main mechanisms driving multiphase matrix-fracture mass transfer. New shape factors for saturation diffusion are defined. It is shown that the prediction of wetting-phase imbibition using the current form of the transfer function can be quite inaccurate, which might have significant consequences from the perspective of reservoir management. Fine-grid single-porosity models are used to verify the validity of the new transfer function. The results from single-block dual-porosity models and the corresponding single-porosity fine-grid models were in good agreement.
Improving Patient Adherence
Authors: Delamater Alan M. 
Published: September 2006

IN BRIEFRegimen adherence problems are common in individuals with diabetes, making glycemic control difficult to attain. Because the risk of complications of diabetes can be reduced by proper adherence, patient nonadherence to treatment recommendations is often frustrating for diabetes health care professionals. This article reviews the scope of the adherence problem and the factors underlying it. The author discusses the concepts of compliance and adherence and offers recommendations for improving adherence by adopting a more collaborative model of care emphasizing patient autonomy and choice.
Implementing Diabetes Self-Management Education in Primary Care
Authors: Emerson Sharlene 
Published: September 2006

In Brief
This article describes an ongoing project being implemented at the University of Pittsburgh Medical Center that is designed to provide diabetes self-management education (DSME) in primary care offices. The author identifies process issues that should be considered when implementing a DSME program in primary care settings and provides helpful information about the billing and revenue issues that can present barriers to reimbursement for DSME services.
Current concepts in apoptosis: The physiological suicide program revisited
Authors: Chowdhury Indrajit , Tharakan Binu , Bhat Ganapathy 
Published: September 2006

AbstractApoptosis, or programmed cell death (PCD), involves a complex network of biochemical pathways that normally ensure a homeostatic balance between cellular proliferation and turnover in nearly all tissues. Apoptosis is essential for the body, as its deregulation can lead to several diseases. It plays a major role in a variety of physiological events, including embryonic development, tissue renewal, hormone-induced tissue atrophy, removal of inflammatory cells, and the evolution of granulation tissue into scar tissue. It also has an essential role in wound repair. The various cellular and biochemical mechanisms involved in apoptosis are not fully understood. However, there are two major pathways, the extrinsic pathway (receptor-mediated apoptotic pathway) and the intrinsic pathway (mitochondria-mediated apoptotic pathway), which are both well established. The key component in both is the activation of the caspase cascade. Caspases belong to the family of proteases that ultimately, by cleaving a set of proteins, cause disassembly of the cell. Although the caspase-mediated proteolytic cascade represents a central point in the apoptotic response, its initiation is tightly regulated by a variety of other factors. Among them, Bcl-2 family proteins, TNF and p53 play pivotal roles in the regulation of caspase activation and in the regulation of apoptosis. This review summarizes the established concepts in apoptosis as a physiological cell suicide program, highlighting the recent and significant advances in its study.
Methemoglobin—It's not just blue: A concise review
Authors: Umbreit Jay 
Published: September 2006

AbstractHemoglobin has functions besides carrying oxygen to the tissues, and regulates vascular tone and inflammation via a redox couple with methemoglobin. Hemoglobin has iron in the reduced valance Fe(II) and methemoglobin has iron in the oxidized valance Fe (III), with a free energy capable of producing water from oxygen. In generating methemoglobin the couple functions as a nitrite reductase. The degree of oxidation of hemoglobin senses the oxygen level in the blood and uses its ability to produce nitric oxide from nitrite to control vascular tone, increasing blood flood when the proportion of oxygenated hemoglobin falls. Additional cardiovascular damage is produced by methemoglobin mediated oxidation of light density lipoproteins, accelerating arteriosclerosis. In addition, the release of heme from methemoglobin is an important factor in inflammation. These physiologic functions are paralleled by thewell‐described role in the oxidation of various drugs resulting in methemoglobinemia. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
Predictable prognostic factor of CD56 expression in patients with acute myeloid leukemia with t(8:21) after high dose cytarabine or allogeneic hematopoietic stem cell transplantation
Authors: Yang Deok‐Hwan , Lee Je‐Jung , Mun Yeung‐Chul , Shin Ho‐Jin , Kim Yeo‐Kyeoung , Cho Sang‐Hee , Chung Ik‐Joo , Seong Chu‐Myong , Kim Hyeoung‐Joon 
Published: September 2006

AbstractCD56 expression in acute myeloid leukemia (AML) has been associated with extramedullary leukemia and multidrug resistance, but its clinical and prognostic significance has not been clearly identified. This study examined CD56 expression in 37 adult de novo AML patients with t(8:21). CD56 was expressed in 25 cases (67.6%). Complete remission (CR) rates were similar in both groups (91.7% vs. 88.7%; P = 0.73), but the relapse rates differed considerably (60% vs. 25%; P = 0.02). The median duration of disease‐free survival (DFS) was significantly shorter in the CD56+ (median, 12.2 ± 6.4 months) than in the CD56− group (median, not reached) (P = 0.02). In addition, the median duration of survival differed significantly in the CD56+ group (median, 14.9 ± 4.4 months) compared with the CD56− group (median, not reached) (P = 0.01). Of the fifteen transplanted patients who achieved CR, allogeneic HST was performed from their siblings. The median duration of DFS in the CD56+ patients was significantly shorter than the CD56− patients (median, 24.4 ± 4.5 months vs. median, not reached; P = 0.02). We concluded that CD56 expression correlates to a reduced DFS and survival for AML patients with t(8:21), including those patients who underwent transplantation. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
Unrelated donor bone marrow transplantation using a chemotherapy‐only preparative regimen for adults with high‐risk acute myelogenous leukemia
Authors: Ayash Lois J. , Ratanatharathorn Voravit , Braun Thomas , Silver Samuel M. , Reynolds Christopher M. , Uberti Joseph P. 
Published: September 2006

AbstractLimited data are available for adults undergoing unrelated donor (URD) BMT for AML using chemotherapy‐only preparative regimens. Previous studies incorporated irradiation, included adults and children, and excluded secondary leukemia. Herein we report long‐term outcomes for adults with poor‐prognostic AML receiving a novel regimen of busulfan (16 mg/kg), cytarabine (8,000 mg/m2), and cyclophosphamide (120 mg/kg) (BAC), followed by URD BMT. From June 1995 through October 2001, 45 adults were enrolled. Adverse features included unfavorable cytogenetics (49%), secondary AML (47%), leukemia at transplant (42%), and extramedullary disease (16%). At time of BMT, 23 were in remission (12 CR1) while 22 had leukemia. Four (9%) died early. Acute and chronic GVHD rates were 44 and 67%, respectively. Seventeen (38%) were disease‐free 52 months post‐BMT; 13 were leukemia‐free (eight CR1) at transplant. Eleven relapsed. Three‐year DFS and OS were 42 and 46%, respectively. DFS and OS were longer, and relapses less, for those in CR at time of BMT. Secondary leukemia, cytogenetics, cell dose, and GVHD did not influence outcome. In poor‐risk AML, BAC provided cytoreduction comparable to reported TBI‐containing regimens, when administered for URD BMT. With decreasing treatment‐related mortality, it is justified to proceed early to URD BMT for patients with poor prognostic features. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
Concurrent immune thrombocytopenic purpura and Guillain‐Barre syndrome in a patient with Hashimoto's thyroiditis
Authors: Kohli Rajan Singh , Bleibel Wissam , Bleibel Hani 
Published: September 2006

AbstractImmune thrombocytopenic purpura (ITP), Guillain‐Barre syndrome (GBS), and Hashimoto's thyroiditis (HT) are autoimmune disorders caused by impaired self‐tolerance mechanisms triggered by interaction between genetic and environmental factors. ITP is an immune‐mediated destruction of platelets resulting in mucocutaneous bleeding, GBS is an ascending motor paralysis caused by an inflammatory demyelination of peripheral nerves, and HT is characterized by autoimmune‐mediated destruction of the thyroid gland. The concurrent development of ITP and GBS has only rarely been reported in the literature, and GBS itself rarely occurs with other autoimmune disorders. We present a 21 year‐old patient with known Hashimoto's hypothyroidism that simultaneously developed GBS and ITP after an upper respiratory tract infection. To the best of our knowledge, this is the first reported case of these three autoimmune disorders in the same patient. This points to a possible common genetic predisposition to these disorders. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
Intrinsische Stickstoff‐Aktivierung an “nackten” Metallatomen
Authors: Himmel Hans‐Jörg , Reiher Markus 
Published: September 2006

AbstractDas Interesse an Metallkomplexen, die molekularen Stickstoff binden und seine Reduktion oder Oxidation unter milden Bedingungen bewirken, ist weiterhin ungebrochen. In der Natur katalysiert das Enzym Nitrogenase diesen Prozess. Unter milden Zellbedingungen findet die Distickstoff‐Fixierung an einem Metall‐Schwefel‐Cluster im Zentrum des MoFe‐Proteins statt. Details des Mechanismus sind jedoch weithin unbekannt, obwohl gerade in den letzten Jahren wichtige Entdeckungen in diesem Gebiet gemacht wurden. Im vorliegenden Aufsatz werden neueste Resultate über Wechselwirkungen von N2 mit Metallatomen und Metallatom‐Dimeren aller Gruppen des Periodensystems diskutiert, die vor allem in Gasphasen‐ und Matrixisolationsexperimenten gewonnen wurden. Die Relevanz dieser intrinsischen Distickstoff‐Aktivierung an ligandenfreien Metallatomen für die entsprechenden Reaktionen an Komplexen, Clustern und Oberflächen wird hervorgehoben.