bluuebunny/crossref_metadata_2025_split huggingface dataset:
Using disposable polydimethylsiloxane fibers to assess the bioavailability of permethrin in sediment
Authors: Hunter Wesley , Xu Yiping , Spurlock Frank , Gan Jay 
Published: February 2008

Abstract
Pyrethroid insecticides are widely used in both agricultural and urban environments. Pyrethroids have been frequently detected in California, USA, stream bed sediments. Pyrethroids are strongly hydrophobic so their bioavailability is determined by their sorption to sediment. In the present study, we used disposable polydimethylsiloxane (PDMS) fibers to sample from the freely dissolved (effective) permethrin concentration that governs bioaccumulation and toxicity, and tested the correlation of those measurements with uptake by Chironomus tentans. In sediments that were incrementally diluted with silica sand, both PDMS fiber and organic carbon (OC) normalized sediment concentrations were highly correlated with C. tentans permethrin uptake. However, for multiple sediments with OC ranging from 1.4 to 27%, C. tentans permethrin uptake showed a better correlation with PDMS fiber concentrations than sediment OC-normalized concentrations. We conclude that the qualitative properties of sediment OC influence permethrin phase distribution and therefore the bioavailability of permethrin in sediment–water systems. Consequently selective methods such as PDMS fibers yield improved estimates of bioaccumulation and toxicity as such methods detect freely dissolved permethrin concentrations in the sediment.
Time and concentration dependency in the potentially affected fraction of species: The case of hydrogen peroxide treatment of ballast water
Authors: Smit Mathijs G.D , Ebbens Eltjo , Jak Robbert G , Huijbregts Mark A.J 
Published: February 2008

AbstractTransport of large volumes of ballast water contributes greatly to invasions of species. Hydrogen peroxide (H2O2) can be used as a disinfectant to prevent the spread of exotic species via ballast water. Instead of using environmental risk assessment techniques for protecting a certain fraction of the species from being affected, the present study aimed to apply these techniques to define treatment regimes of H2O2 and effectively eliminate as many species as possible. Based on time-dependent dose–response curves for five marine species (Corophium volutator, Artemia salina, Brachionus plicatilis, Dunaliella teriolecta, and Skeletonema costatum), time-dependent species-sensitivity distributions (SSDs) were derived for different effect sizes. The present study showed that H2O2 can be used effectively to treat ballast water but that relatively high concentrations and long treatment durations are required to eliminate the vast majority of species in ballast water. The described toxicant effectiveness approach using SSDs also has other potential fields of application, including short-term application of biocides.
Chronic sublethal effects associated with branched alkylbenzenes bioaccumulated by mussels
Authors: Scarlett Alan , Rowland Steven J , Galloway Tamara S , Lewis Alistair C , Booth Andy M 
Published: February 2008

Abstract
Crude oils are complex mixtures of many thousands of compounds, both resolved and unresolved by conventional gas chromatography (GC). Recent research using comprehensive two-dimensional gas chromatography–time-of-flight–mass-spectrometry (GC × GC-ToF-MS) identified branched alkylbenzenes (BABs) as a major component of some unresolved complex mixtures of hydrocarbons (UCMs) bioaccumulated in the tissues of North Sea mussels, Mytilus edulis, previously found to have poor health status. Here the effect of long-term exposure to low aqueous concentration of BABs and mussels' ability to recover, was determined. Mussels were exposed to 5 μg/L of a complex mixture of C12–14 BABs for 14 d. Feeding rates and the viability of hemocytes were measured immediately after exposure and again after 5 d depuration. Tissues were extracted, analyzed and alkylbenzenes quantified by both GC-MS and GC × GC-ToF-MS. Mussel extracts from previous acute tests were also reanalyzed and quantified using GC × GC-ToF-MS. Mussels exposed to 5 μg/L BABs for 14 d accumulated 46 to 47 μg/g dry weight alkylbenzenes; this was similar to tissue concentrations of mussels exposed to 41 μg/L for 72 h. Feeding rates were significantly reduced (p ≤ 0.05) and were dependent upon tissue concentration. Cellular viability was not significantly affected. Following 5 d in clean seawater, the BABs were only partially depurated and feeding rates failed to fully recover. The use of GC × GC-ToF-MS in the present study has shown that mussel tissue concentrations of complex mixtures of alkylbenzenes, and their corresponding effects, are consistent with reported concentrations within UCM-contaminated wild mussel populations with poor health status.
Toxicity equivalency values for polychlorinated biphenyl mixtures
Authors: Burkhard Lawrence P , Lukasewycz Marta T 
Published: February 2008

Abstract
For aquatic, avian, and mammalian species, dioxin equivalency values (TEQs) were computed for Aroclor, Clophen, Kanechlor, Chlorofen, Sovol, Delor, Phenoclor, and Chinese polychlorinated biphenyl (PCB) mixtures by using World Health Organization toxicity equivalency factors (TEFs) and compound-specific compositional data for PCBs, polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) for the individual mixtures. The TEQs were similar across the different PCB product lines for mixtures of similar chlorine content. Depending on the PCB mixture, the polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) in the mixture contributed anywhere from 0 to 96% of the total TEQs, and the impact of PCDD/Fs was greatest for the fish TEQs. In comparison to the dioxin-like PCBs, few measurements have been performed for PCDD/Fs in the commercial PCB products.
Distribution of polybrominated diphenyl ethers in fish tissues from the Pearl River Delta, China: Levels, compositions, and potential sources
Authors: Guo Ying , Meng Xiang-Zhou , Tang Hong-Lei , Mai Bi-Xian , Zeng Eddy Y 
Published: February 2008

AbstractFish tissues from three different farming types (freshwater farmed, seawater farmed, and seawater wild fish collected from the Pearl River Delta of South China), including skin, gills, gastrointestinal tract (GIT), liver, and muscle, were analyzed for polybrominated diphenyl ethers (PBDEs). In general, the dry weight based concentrations of Σ10PBDE (sum of BDE-28, -47, -66, -85, -99, -100, -138, -153, -154, and -183) in fish tissues followed the sequence of liver &gt; gill &gt; skin &gt; GIT and muscle. The BDE congener profiles varied with fish species. Decabrominated diphenyl ether was detected in 37.4% of the total 187 samples, and this ratio may actually have been underestimated because the reporting limit for BDE-209 was considerably higher than those for other congeners. Decabrominated diphenyl ether was the dominant BDE congener in skin and GIT, and less abundant in gills, muscle, and liver. Except for skin, no significant difference in BDE-209 lipid-normalized concentrations was observed among fish tissues. These results suggest that BDE-209 can occur abundantly in the fish species under investigation, somewhat inconsistent with the results from most previous studies that reported low bioaccumulative potential of BDE-209. Combined with the likelihood that BDE-209 can be debrominated into lower brominated congeners that tend to be more toxic than BDE-209, the abundant occurrence of BDE-209 could continue to pose prolonged health risk to the ecological environment.
Spatial trends of perfluoroalkyl compounds in ringed seals (Phoca hispida) from the Canadian Arctic
Authors: Butt Craig M , Mabury Scott A , Kwan Michael , Wang Xiaowa , Muir Derek C.G 
Published: February 2008

Abstract
The present study examined spatial trends of perfluoroalkyl compounds (PFCs) in liver samples from 11 populations of ringed seals (Phoca hispida) in the Canadian Arctic from 2002 to 2005. Trophic position and relative carbon sources were compared by analyzing stable nitrogen and carbon isotopes in muscle samples. Geometric mean concentrations of total C9–C15 perfluorinated carboxylates (PFCAs) ranged from 8.8 to 84 ng/g wet weight, and C9–C11 PFCAs predominated. Perfluorooctane sulfonate was the dominant PFC measured, with concentrations ranging from 6.5 to 89 ng/g wet weight, contributing between 29 and 56% of the total PFC concentration. Overall, mean PFC concentrations were similar between populations, and differences were attributed largely to elevated levels in the Gjoa Haven (Rae Strait, central Canadian Arctic archipelago) and Inukjuak populations (eastern Hudson Bay) and to lower concentrations at Pangnirtung (Cumberland Sound, Baffin Island). Mean stable nitrogen isotope ratios (±95% confidence intervals) ranged from 14.7‰ (±0.3‰) at Nain (Labrador) to 17.9‰ (±0.7‰) at Gjoa Haven, suggesting that all populations were within the same trophic level. Stable carbon isotope ratios varied widely between the seal populations, ranging from —22.9‰ (±0.2‰) at Gjoa Haven to — 17.7‰ (±0.4‰) at Nain. The δ13C ratios from Gjoa Haven were significantly more depleted than those for other populations and may suggest a terrestrially based carbon source. The depleted stable carbon isotope ratio may explain the elevated PFC concentrations in the Gjoa Haven population. Analysis of covariance indicated that δ13C was a significant covariable for seven of nine seal populations for which δ13C values were available. After adjusting for δ13C values, concentrations of most PFCs generally were statistically greater in the Grise Fiord, Qikiqtarjuaq, Arviat, and Nain populations.
Anti-Saccharomyces cerevisiae Antibodies in Acute Myocardial Infarction
Authors: Cinemre Hakan , Bilir Cemil , Gokosmanoglu Feyzi , Kadakal Figen 
Published: February 2008

Background Elevated anti- Saccharomyces cerevisiae antibody (ASCA) immunoglobulin (IgG) and IgA levels were first described in the serum of Crohn disease patients and have increasingly been reported in other inflammatory diseases. The role of in situ and remote inflammation in atherosclerosis is a major area of interest. In this study, we compared ASCA IgG and IgA levels in acute myocardial infarction (AMI) and controls to investigate the possible role of ASCA in AMI. Methods Serum samples were obtained from 140 consecutive patients who presented to the emergency department with acute chest pain. AMI was diagnosed by electrocardiography and serial enzymes. Patients ruled out for acute coronary event were grouped as controls. ASCA IgA and IgG levels were determined using enzyme-linked immunosorbent assay. Groups were compared for statistically significant difference. Results ASCA IgG titers ranged between 0.1 and 31.0 RIU/mL (mean 4.92) in the AMI group and 0.1 and 6.0 (mean 0.84) in the controls. The groups were found to differ very significantly ( p = .001). ASCA IgA titers ranged between 2.0 and 200.0 RIU/mL (mean 13.73) in the AMI group and 2.0 and 11.5 RIU/mL, (mean 4.25) in controls. The groups differed significantly ( p = .32). AMI and controls were also analyzed for ASCA IgA and IgG positivity. Both groups differed significantly from controls ( p = .013). Conclusion Elevated ASCA IgA and IgG levels as well as ASCA positivity in the AMI might suggest use of ASCA as a marker for atherosclerotic plaque instability. It might also provide a link between inflammatory processes and increased cardiovascular risk. Further studies are needed on a Saccharomyces cerevisiae-based diet, related intestinal colonization, and associated inflammation, autoimmune disorders, and cardiovascular events.
Toward Early Identification of Acute Lung Injury in the Emergency Department
Authors: Freishtat Robert J. , Mojgani Bahar , Mathison David J. , Chamberlain James M. 
Published: February 2008

Background There are no studies evaluating the epidemiology of pediatric acute lung injury (ALI) in the emergency department (ED), where early identification and interventions are most likely to be helpful. The purpose of this study was to describe the epidemiology of the ALI precursor acute hypoxemic respiratory failure (AHRF) in the ED. Methods We analyzed 11,664 pediatric patient records from 16 EDs. Records were selected if oxygen saturation (SpO2) was recorded during the visit. Virtual partial pressure of oxygen (pO2) was calculated from SpO2, thus allowing calculation of ratios of pO2 to fraction of inspired oxygen (FiO2) (PFRs). Patients with a PFR < 300 were classified as having AHRF. Univariate analyses and logistic regression were used to test the association of clinical factors with the presence of AHRF and intubation. Results AHRF criteria (ie, PFR < 300) were met in 121 (2.9%) of the 4,184 patients with an oxygenation measurement. The following variables were independently associated with ALI: higher Pediatric Risk of Admission II score (adjusted odds ratio [95% confidence interval (CI)] = 1.12 [1.08-1.16]; p < .001), higher heart rate (1.02 [1.01-1.03]; p = .009), a positive chest radiograph (2.35 [1.02-5.43]; p = .045), and lower temperature (0.49 [0.36-0.68]; p < .001). The final model had an R2= .20. Conclusion We found nonintubated AHRF to be prevalent in the ED. The low R2for the regression model for AHRF underscores the lack of criteria for early identification of patients with respiratory compromise. Our findings represent an important first step toward establishing the true incidence of ALI in the pediatric ED.
Visualizing transcription in real-time
Authors: Brody Yehuda , Shav-Tal Yaron 
Published: February 2008

Abstract
The transcriptional process is at the center of the gene expression pathway. In eukaryotes, the transcription of protein-coding genes into messenger RNAs is performed by RNA polymerase II. This enzyme is directed to bind at upstream gene sequences by the aid of transcription factors that assemble transcription-competent complexes. A series of biochemical and structural modifications render the polymerase transcriptionally active so that it can proceed from an initiation state into a functional elongating phase. Recent experimental efforts have attempted to visualize these processes as they take place on genes in living cells and to quantify the kinetics of in vivo transcription.
Comparison of pathogenic properties of the murid gammaherpesvirus (MuHV 4) strains: a role for immunomodulatory proteins encoded by the left (5′-)end of the genome
Authors: Mistríková Jela , Rajčáni Július 
Published: February 2008

Abstract
The murid herpesvirus 4 (MuHV 4) species encompasses 7 isolates, out of which at least two (MHV-68, MHV-72) became in vitro propagated laboratory strains. Following intranasal inoculation, MuHV 4 induces an acute infectious mononucleosis-like syndrome with elevated levels of peripheral blood leukocytes, shifts in the relative proportion of lymphocytes along with the appearance of atypical mononuclear cells. At least two isolates exhibited spontaneous deletions at the left hand (5′-end) of their genome, resulting in the absence of M1, M2, M3 genes (strain MHV-72) and also of the M4 gene (strain MHV-76). Based on DNA sequence amplifications only, another two isolates (MHV-Šum and MHV-60) were shown to possess similar deletions of varying length. During latency (until 24 months post-infection), the mice infected with any MuHV 4 isolate (except MHV-76) developed lymphoproliferative disorders. The lack of tumor formation in MHV-76 infected mice was associated with persistent virus production at late post-infection intervals. In addition to careful analysis of spontaneously occurring 5′-end genome defects, our knowledge of the function of 5′-end genes relies on the behaviour of mutants with corresponding deletions and/or insertions. While M2 and M3 genes encode immune evasion proteins, M4 codes for a soluble glycopeptide acting as immunomodulator and/or immunostimulator.
Prenatal testosterone improves the spatial learning and memory by protein synthesis in different lobes of the brain in the male and female rat
Authors: Gurzu Cristian , Artenie Vlad , Hritcu Lucian , Ciobica Alin 
Published: February 2008

Abstract
The high density of the steroid hormone receptors in the structures of temporal lobe involved in learning and memory, such as the hippocampus, perirhinal cortex, entorhinal cortex and amigdaloid complex, shows that there must be a direct relationship between gonadal hormones and organizational effects of steroid hormones in those structures during development of the nervous system. The present study was undertaken in order to investigate the effect of testosterone administration during the third week of gestation on the spatial memory formation of the offspring rats and the level of soluble proteins in the temporal lobe and frontal lobe of brain, as evidence of important organizational effects of androgens during prenatal development in brain sexual dimorphism. Animals have received testosterone undecanoate on days 14, 15, 16 and 19, 20, 21 of gestation. Learning and memory tests were started 100 days after the testosterone treatment. At the end of the experiments, the temporal and frontal lobes of brain were removed for assessing the level of soluble proteins. Testosterone treatment significantly improved spontaneous alternations percentage of male offspring in Y-maze task comparative with female offspring and reference memory in radial 8 arm-maze task (decreasing in number of reference memory errors in both male and female offspring groups), suggesting effects of both short and long-term memory. Also, testosterone significantly increased the brain soluble protein level of treated female rats in 14–16 prenatal days compared with the control group as well as the brain soluble protein level of treated male rats. These results suggest that steroid hormones play an important role in the spatial learning and memory formation by means of protein synthesis in different lobes of the brain.
Rhinolithiasis: Clinical, Radiological, and Mineralogical Features
Authors: Yildirim Nadir , Arslanoglu Atilla , Sahan Murat , Yildirim Altan 
Published: February 2008

Background Rhinolithiasis is a rare and under-diagnosed clinical entity whose etiology and pathogenesis is poorly understood. Objective The objective of the study is to review the clinical and radiologic features of rhinolithiasis and mineralogical–chemical composition of the rhinoliths with the aim of shedding light on its etiology and pathogenesis. Methods Our subjects consisted of 8 rhinolithiasis cases. Clinical presentations, signs, and symptoms of the patients with radiologic findings are presented, and X-ray diffraction analyses of the stones were carried out to assess their mineralogical composition. Results Nasal obstruction appeared to be the chief symptom, followed by nasal discharge and facial pain. Neither exogenous nor endogenous nidi were identified in any of the cases. Mineralogical analyses of the rhinoliths revealed Whitlockite [(Ca, Mg)3 (PO4)2] in one and Dahllite [Ca5 (PO4, CO3)3OH] in 7 cases. Conclusion We hypothesized that some substances or organic objects form the nidi of the rhinoliths and are disintegrated over the course of mineral precipitation. This hypothesis was supported by radiologic and microscopic findings.
Inhalation Challenge Test in the Diagnosis of Occupational Rhinitis
Authors: Airaksinen Liisa K. , Tuomi Timo O. , Tuppurainen Matti O. , Lauerma Antti I. , Toskala Elina M. 
Published: February 2008

Background Evaluations of rhinitis reactions in inhalation challenges (ICs) are sparse compared with research on nasal challenges. This study evaluates the outcome of IC tests in assessing occupational rhinitis (OR). It presents the largest rhinologic IC data in the literature, analyzing the exposure method of various agents causing OR and their relation to asthma. Methods Challenge tests performed on 829 individuals with suspected cases of OR were reviewed. Results from both exposures with occupational agents (n = 1229) and placebo (n = 838) were evaluated. Results A total of 10% of the occupational ICs (n = 123) were positive, suggesting OR, and 13% (n = 161) showed asthmatic reaction in the same challenge. In control challenges 2% showed rhinitis and 6% showed asthma symptoms. The most common agents tested were molds (160 tests), flours, and animal fodders (115 tests) and formaldehyde (122 tests). Obeche wood dust and latex produced positive nasal reactions the most frequently, followed by acid anhydrides. Conclusion Although IC is a resource-intensive methodology, the evaluation of nasal symptoms and signs together with bronchial reactions saves time and expense compared with the organization of multiple individual challenges. We encourage the simultaneous evaluation of both nasal and bronchial reactions in IC tests.
The Silent Sinus Syndrome is a form of Chronic Maxillary Atelectasis: A Systematic Review of all Reported Cases
Authors: Brandt Michael G. , Wright Erin D. 
Published: February 2008

Background The terms chronic maxillary atelectasis (CMA) and silent sinus syndrome (SSS) have been used to describe spontaneous enophthalmos in association with a contracted ipsilateral maxillary sinus. Despite the use of differing taxonomy, it appears that these two terms describe the same clinical entity. Nevertheless, many reports still discuss CMA and SSS in isolation or as distinct conditions. Methods A systematic review of all reported cases of CMA and SSS was performed (1964-2006). Case reports were excluded if they involved facial trauma, diagnosis of mucocele, or previous surgery. Eligible cases were reviewed and entered into a database. Data were evaluated based on literature of publication, reported diagnosis, demographics, ophthalmologic examination, results of imaging, and operative findings. Only complete data sets were included in an additional analysis whereby the diagnostic criteria for CMA and SSS were applied and the data sets were compared. Results Of the 105 cases reviewed, 55 contained complete data sets. Twenty-seven of these cases met the diagnostic criteria for SSS, and 48 could be diagnosed as CMA, with 23 meeting the criteria for both conditions. Comparing the cases across diagnoses, the only difference observed was that of the presence of sinus-related symptoms, which by definition distinguishes CMA III from SSS. Conclusion The entity termed SSS fits within the staging classification of CMA. We propose abandoning the term SSS and recommend universal adoption of the CMA staging system, which uses nomenclature that more accurately portrays the pathophysiology and natural history of this condition.
Orbital Exenteration: A Dilemma in Mucormycosis Presented with Orbital Apex Syndrome
Authors: Songu Murat , Unlu H. Halis , Gunhan Kivanc , Ilker S. Sami , Nese Nalan 
Published: February 2008

Background Mucormycosis is an uncommon, rapidly progressive, commonly fatal, opportunistic, fungal paranasal sinus infection. The most critical decision in the management of rhino-orbital mucormycosis is whether the orbit should be exenterated. The literature fails to provide a broad base of information of how physicians determine the need for exenteration in daily practice. The decision for exenteration often depends on the judgment of the treating otolaryngologist. The authors report their experience and outline that orbital exenteration may not be mandatory in all cases of rhino-orbital mucormycosis. Methods The medical records from Celal Bayar University Medical Faculty Department of Otorhinolaryngology/Head and Neck Surgery were retrospectively searched from 1995 to 2007 for three cases with rhino-orbital mucormycosis, treated without orbital exenteration. Results All patients with rhino-orbital mucormycosis who were treated without exenteration survived. Conclusion The favorable outcome was attributable to rapid correction of the underlying medical condition; wide local excision and debridement of all involved and devitalized sinonasal and periorbital tissue, while establishing adequate sinus and orbital drainage; daily endoscopic assessment with multiple sinus debridement when necessary; daily irrigation of the involved areas; and high-dose i.v. amphotericin B.