bluuebunny/crossref_metadata_2025 huggingface dataset:
Circulating immune complexes as indicators of environmental contamination
Authors: Ramanaviciene A. , Acaite J. , Ramanavicius A.
Published: September 2004

The aim of this study was to examine the effect of environmental contamination on the concentration of circulating immune complexes (CIC) in bovine blood. We determined that in a conventionally ecologically clear district, the CIC concentration in healthy bovine blood serum was within the limits of 0.18–0.52 mg/mL, (mean = 0.31 mg/mL, V = 30.14%). In a conventionally ecologically contaminated district, the CIC concentration in healthy bovine blood serum was detected within the limits of 0.48–0.99 mg/mL (mean = 0.65 mg/mL, V = 17.97%; P < 0.05). The CIC concentration in serum of bovine leukemia virus (BLV)–infected bovines from different districts was within the limits of 0.29–1.76 mg/mL (mean = 0.81 mg/mL, V = 36.67%; P < 0.05). According to these preliminary results of the investigation, it may be supposed that the increased concentration of CIC is closely related to the environmental contamination. Therefore, studies of CIC concentration in healthy mammals are of great importance for the monitoring of anthropogenic factors and can be exploited as an indicator of environmental contamination. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 505–509, 2004.
Life‐history traits of standard and autochthonous cladocerans: I. Acute and chronic effects of acetylsalicylic acid
Authors: Marques Catarina R. , Abrantes Nelson , Gonçalves Fernando
Published: September 2004

Pharmaceuticals have been recognized as an important group of aquatic micropollutants, mainly because of their biologically active nature. Acetylsalicylic acid (ASA), which is the active compound of Aspirin® and many other pharmaceuticals, is consumed in large quantities every year. Therefore, its acute and chronic effects on standard (Daphnia magna) and autochthonous (Daphnia longispina) daphnids were investigated. The results showed that ASA impaired the survivorship, reproduction, and growth of the cladoceran species. The standard daphnid was the more tolerant species in acute assays (48‐h EC50 = 1293.05 mg/L; D. longispina: 48‐h EC50 = 647.31 mg/L); whereas the autochthonous daphnid seemed to be more resistant under chronic exposure to ASA, mainly its population‐level traits. Despite this, the observed effect concentrations were much higher than the environmental concentrations of ASA. Notwithstanding this, the impairment of individual‐level traits is likely to occur at environmental levels as an ultimate response to long‐term exposure. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 518–526, 2004.
Sonographic cervical length in singleton pregnancies with intact membranes presenting with threatened preterm labor
Authors: Fuchs I. B. , Henrich W. , Osthues K. , Dudenhausen J. W.
Published: September 2004

Objective

Less than 10% of women presenting with preterm contractions progress to active labor and delivery. This study investigates whether cervical length measurements by ultrasound can discriminate between true and false labor in women presenting with threatened preterm labor.

Methods

Cervical length was measured by transvaginal ultrasound in 253 women with singleton pregnancies presenting with painful uterine contractions at a median age of 31 (range, 24–35) weeks of gestation. Women presenting in active labor, defined by the presence of cervical dilatation of ≥ 3 cm, those with ruptured membranes and those that underwent prior or subsequent cervical cerclage were excluded from the study. The clinical management was determined by the attending obstetrician without taking into account the cervical length. Primary outcome of the study was delivery within 7 days of presentation based on the results of randomized studies on the use of tocolytics in women with preterm labor that reported a prolongation of pregnancy by 7 days.

Results

Delivery within 7 days of presentation occurred in 21/253 (8.3%) pregnancies and this was inversely related to cervical length. Receiver–operating characteristics (ROC) curves established a cervical length of 15 mm as the most relevant cut‐off level for the prediction of preterm delivery within 7 days. In 217 cases the cervical length was ≥ 15 mm and only four of these (1.8%) delivered within 7 days. In the 36 women with cervical length < 15 mm, delivery occurred in 17 (47.2%) within 7 days. Logistic regression analysis demonstrated that significant independent contribution in the prediction of delivery within 7 days was provided by cervical length, contraction frequency at presentation, previous history of preterm delivery and vaginal bleeding. There was no significant contribution from gestation at presentation, ethnic origin, maternal age, parity, cigarette smoking or the administration of tocolysis, antibiotics or steroids. Similar results were shown in a subanalysis of 162 patients presenting at a gestational age below 32 weeks: 9/19 patients (47.4%) with a cervical length below 15 mm delivered within 7 days compared to 3/143 (2.1%) with a cervical length ≥ 15 mm. Univariate as well as multivariate analyses confirmed cervical length to be a significant independent predictor of delivery within 7 days in this population.

Conclusions

Sonographic measurement of cervical length helps to avoid overdiagnosis of preterm labor in women with preterm contractions and intact membranes. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
PVC modification through polymerization of a monomer absorbed in porous suspension‐type PVC particles
Authors: Narkis M. , Shach‐Caplan M. , Haba Y. , Silverstein M. S.
Published: September 2004

In‐situ polymerization is the polymerization of one monomer in the presence of another polymer. It can be performed by sequential emulsion polymerization, or by reactions in the melt, in the solid phase, or in solution. The current report describes two methods to obtain poly(vinyl chloride) (PVC) modification through polymerization of a monomer absorbed in commercial porous suspension‐type PVC particles. The generated modified PVC products differ significantly in their structure and properties. The first approach includes absorption of a monomer/peroxide solution within porous suspension‐type PVC particles, followed by polymerization/crosslinking in the solid state at 80°C in an aqueous stabilizer‐free dispersion. The monomer/crosslinker pairs selected are styrene/DVB (divinyl benzene), methylmethacrylate/EGDMA (ethylene glycol dimethacrylate), butyl acrylate/EGDMA, and ethylhexyl acrylate/EGDMA. The influence of composition and nature of the polymerizing/crosslinking constituents on the modified PVC particle structure was studied by microscopy methods, porosity measurements, and dynamic mechanical behavior (DMTA). The level of molecular grafting between PVC and the modifying polymer was determined by solvent extraction experiments. This work shows that the different monomers used represent distinct courses of monomer transport through the PVC particles. The characteristics of the modified PVC particle indicate that the polymerization/crosslinking process occurs in both the PVC bulk, i.e., within the walls constituting a particle, and in the PVC pores. No indication of chemical intermolecular interaction within the modified PVC particles was found. In the second approach, a solution of monomer, initiator, and a crosslinking agent is absorbed in commercial suspension‐type porous PVC particles, thus forming a dry blend. This dry blend is subsequently reactively polymerized in a twin‐screw extruder at an elevated temperature, 180°C, in the molten state. The properties of the reactively extruded PVC/PMMA blends are compared with those of physical blends at similar compositions. Owing to the high polymerization temperature, short‐chain polymers are formed in the reactive polymerization process. Reactively extruded PVC/PMMA blends are transparent, form single‐phase morphology, have a single Tg, and show mechanical properties comparable with those of the neat PVC. The resulting reactively extruded PVC/PMMA blends have high compatibility. J. Vinyl Addit. Technol. 10:109–120, 2004. © 2004 Society of Plastics Engineers.
Effect of metal stearate antacid on the melt stabilization performance of phenolic/phosphite antioxidants in metallocene LLDPE. Part 2: Discoloration
Authors: Hoàng Eric M. , Liauw Christopher M. , Allen Norman S. , Fontán Eusebio , Lafuente Pilar
Published: September 2004

The first part of this series of papers indicated that the melt stabilization performance of phenol/phosphite/metal stearate combinations in metallocene LLDPE (mLLDPE) was influenced by the purity of the fatty acid salt. In this second part, it is shown that the quality of the metal stearate has a direct influence on the discoloration of the aforementioned formulations in the melt state. On the basis of the peroxide and oxide impurity levels in the metal stearates (Part 1), it is suggested that discoloration is directly related to the formation of oxidative transformation products of the phenolic antioxidant. Furthermore, it was observed that the calcium stearates discolored upon aging in air at processing temperatures, while zinc stearates did not. Such discoloration is believed to be partly due to the combination of high levels of conjugated systems consisting of unsaturation and carbonyl groups formed during aging. J. Vinyl Addit. Technol. 10:144–148, 2004. © 2004 Society of Plastics Engineers.
Development of a portable x‐ray fluorescence spectrometer equipped with two monochromatic x‐ray sources and silicon drift detector and field analysis of Islamic glasses at an excavation site in Egypt
Authors: Nakai I. , Yamada S. , Terada Y. , Shindo Y. , Utaka T.
Published: September 2004

A portable x‐ray fluorescence spectrometer equipped with a silicon drift detector (SDD) and a digital signal processor (DSP) was developed for in‐field analysis of archeological samples at an excavation site. This spectrometer allows us to carry out highly sensitive analyses of various elements with atomic numbers down to Na in air by using two monochromatic x‐ray sources obtained by doubly bent toroidal monochromators of graphite (0002) (Pd Kα for medium–heavy elements) and PET (200) (Pd Lα for light elements) and white x‐rays with a Zr filter excited at 40 kV for heavy elements. The detection limit was 0.31% for Al and 4 ppm for Sr in a standard cement sample. The spectrometer was set in a room of the excavation laboratory at al‐Tūr Sinai in the Sinai Peninsula in Egypt in the summer of 2001. The Middle Eastern Culture Center has been conducting an excavation of the sites in al‐Tūr al‐Kilani and Rāya, which were important port cities of Red Sea trade from early Islamic periods: al‐Tūr (A.D.14–20) and Rāya (A.D.8–12). The instrument was operated without any problems and 222 glass objects, 26 pottery sherds, seven pigments and 88 metallic objects were analyzed non‐destructively during a 1 month stay. Since this was the first chemical analysis done at the sites, many important archaeological findings were obtained in the present study. Glass objects were successfully classified based on their chemical compositions. Characterization of stained (luster) glasses was conducted. Copyright © 2004 John Wiley & Sons, Ltd.
A new approach to the determination of the Fano factor for semiconductor detectors
Authors: Papp T. , Lépy M.‐C. , Plagnard J. , Kalinka G. , Papp‐Szabó E.
Published: September 2004

Values of the Fano factor are widely scattered in the literature, indicating the difficulties in its determination. We chose to analyze both the escape peaks and parent peaks of Ge detector spectra where the parent peak penetration depth and the escape peak escape depth are much larger than the size of the incomplete charge collection region. Hence, the escape peaks are expected to be free of low‐energy tailing as, although the actually deposited energy is low, it is deposited beyond the incomplete charge collection region. It was found that the product of electron–hole pair creation energy (ε) and the Fano factor (F) has an energy dependence at low energies, as is expected from electron transport theories. Although ε is expected to have its own energy dependence, if a reference value of 2.96 eV is assumed for ε, then the Fano factor values varied between 0.059 and 0.083. The escape peak is less advantageous for Si, hence a different method was used for Si(Li) detectors. Assuming the reference value of 3.8 eV for ε, the Fano factor was found to be 0.063 at 5.9 keV x‐ray energy. We consider the Fano factors reported here as upper limits, rather than the mean values. Copyright © 2004 John Wiley & Sons, Ltd.
Empirical coefficients models for x‐ray fluorescence analysis of intermediate‐thickness samples
Authors: Sitko Rafał
Published: September 2004

Empirical coefficients models for correction of matrix effects in intermediate‐thickness samples are presented. Two proposed mathematical models correct simultaneously matrix effects and various masses per unit area of the samples. In the first model, it is necessary to know the masses per unit area of the samples and in the second model masses are predicted from the scattered radiation. To calculate coefficients of the models, a series of multi‐element intermediate‐thickness standards with various compositions and various masses per unit area are required. The models were tested experimentally using synthetic samples pressed into pellets and geological certificate reference materials collected on a membrane filter. The calculated concentrations were in good agreement with the certificate values. Copyright © 2004 John Wiley & Sons, Ltd.
Influence of and correction for moisture in rocks, soils and sediments on in situ XRF analysis
Authors: Ge Liangquan , Lai Wanchang , Lin Yanchang
Published: September 2004

This paper discusses the influence of water contained in rocks, soils and sediments on in situ XRF analysis with a portable XRF analyzer. Water in natural rocks, soil and sediments absorbs the characteristic x‐rays from the elements and also causes the primary radiation from the excitation sources to scatter, which results in a decrease in the intensity of characteristic x‐rays and an increase in the intensity of scattered x‐rays in a fluorescence spectrum. A method for correcting for the influence of the water on the analysis of wet samples is proposed, based on the fact that the intensity of scattered radiation is directly proportional to the water content of wet samples. Tests on a set of wet soil samples showed that the method can effectively correct for the influence of the water in wet samples up to a 20% water content. The method was also applied to the analysis of soil with an IED‐2000P XRF analyzer in a copper prospecting area in Yunnan, China. The results show satisfactory agreement of the results for Cu, Zn and Sr analyses before and after rain. Copyright © 2004 John Wiley & Sons, Ltd.
Learning relationships: Teacher‐student connections, learning, and identity in high school
Authors: Bernstein‐Yamashiro Beth
Published: September 2004

Personal mentoring connections between teachers and students in high school are unique components of the developmental process and carry great potential for community‐building at school.
Emotional intelligence and staff training in after‐school environments
Authors: Seligson Michelle , MacPhee Marybeth
Published: September 2004

Staff and youth can provide developmentally significant relationships for one another in out‐of‐school programs.
A prospective study of the relationship between musculoskeletal or psychological complaints and muscular responses to standardized cognitive and motor tasks in a working population
Authors: Steingrómsdóttir Ólöf Anna , Vøllestad Nina Køpke , Knardahl Stein
Published: September 2004

The present study sought to determine the relationship between musculoskeletal or psychological complaints and muscular responses to standardized cognitive and motor tasks. The prospective study design examined (i) whether complaint severity predicts muscular responses during standardized tasks and (ii) whether the muscular responses predict changes in complaint severity over one year. Musculoskeletal and psychological complaints were recorded by monthly reports the four months preceding and 12 months succeeding a work session in the laboratory; complaint‐severity indices were computed from complaint‐severity scores (intensity score × duration score). Surface electromyography (EMG) was recorded bilaterally from the upper trapezius, middle deltoid, and forearm extensor muscles in 45 post‐office workers (30 women) during two identical task series. Between the series, exhausting submaximal muscle contractions (25% of peak torque) were performed. In adjusted regression models, no relations between musculoskeletal complaints the last four months and muscle activity during the task series were found. However, psychological complaints the last four months predicted higher muscle activity levels and a steeper rise in muscle activity in the muscles not engaged in motor task performance. Sleep disturbance was the strongest individual predictor of increased muscle responses. In contrast, psychological complaints the last four months predicted lower EMG levels in the task‐engaged muscle during the complex‐choice‐reaction‐time tasks. None of the muscle‐activity responses to the standardized tasks predicted changes in severity of musculoskeletal or psychological complaints over the subsequent one‐year period. In conclusion, psychological complaints predict different responses in task‐engaged and non‐involved muscles during cognitive and motor tasks. Musculoskeletal complaints did not predict responses to the tasks.
Androgen dependent development of a modified anal fin, gonopodium, as a model to understand the mechanism of secondary sexual character expression in vertebrates
Authors: Ogino Yukiko , Katoh Hironori , Yamada Gen
Published: September 2004

Male external genitalia show structural variations among species. Androgenic hormones are essential for the morphological specification of male type copulatory organs, while little is known about the developmental mechanisms of such secondary sexual characters. Western mosquitofish Gambusia affinis may offer a clue to the sexual differentiation researches, because they show a prominent masculine sexual character for appendage development, anal fin to gonopodium (GP) transition, and its formation could be induced in early juvenile fry by exogenously supplied androgens. We show that GP development is promoted by androgen dependent augmentation of sonic hedgehog (Shh) expression. Two AR cDNAs were cloned and identified as ARα and ARβ from western mosquitofish. Both ARs were predominantly expressed in the distal region of outgrowing anal fin rays. Exposure of fry to androgen caused anal fin outgrowth concomitant with the Shh induction in the distal anal fin ray epithelium. When AR signaling was inhibited by its antagonist flutamide in fry, the initial induction of the Shh was suppressed accompanying retarded anal fin outgrowth. Similar suppression of anal fin outgrowth was induced by treatment with cyclopamine, an inhibitor of Shh signaling. These observations indicate that androgen dependent Shh expression is required for anal fin outgrowth leading to the formation of a genital appendage, the GP in teleost fishes. Androgen‐induced GP formation may provide insights into the expression mechanism regulating the specification of sexual features in vertebrates.
An oxo‐ferryl tryptophan radical catalytic intermediate in cytochrome c and quinol oxidases trapped by microsecond freeze‐hyperquenching (MHQ)
Authors: Wiertz Frank G.M. , Richter Oliver-Matthias H. , Cherepanov Alexey V. , MacMillan Fraser , Ludwig Bernd , de Vries Simon
Published: September 2004

The pre‐steady state reaction kinetics of the reduction of molecular oxygen catalyzed by fully reduced cytochrome oxidase from Escherichia coli and Paracoccus denitrificans were studied using the newly developed microsecond freeze‐hyperquenching mixing‐and‐sampling technique. Reaction samples are prepared 60 and 200 μs after direct mixing of dioxygen with enzyme. Analysis of the reaction samples by low temperature UV–Vis spectroscopy indicates that both enzymes are trapped in the PM state. EPR spectroscopy revealed the formation of a mixture of two radicals in both enzymes. Based on its apparent g‐value and lineshape, one of these radicals is assigned to a weakly magnetically coupled oxo‐ferryl tryptophan cation radical. Implications for the catalytic mechanism of cytochrome oxidases are discussed.
pKa of the essential Glu54 and backbone conformation for subunit c from the H+‐coupled F1F0 ATP synthase from an alkaliphilic Bacillus
Authors: Rivera-Torres Iván O. , Krueger-Koplin Ray D. , Hicks David B. , Cahill Sean M. , Krulwich Terry A. , Girvin Mark E.
Published: September 2004

The conformation of the ATP synthase c‐subunit and the pK
a of its essential E54 residue were characterized in alkaliphilic Bacillus pseudofirmus OF4. The c‐subunit folds as a helix–loop–helix, with inter‐helical contacts demonstrated by paramagnetic relaxation effects. The E54 pK
a of 7.7 is significantly higher than in non‐alkaliphiles, which likely prevents proton loss from the c‐rotor at high pH. The E54 pK
a was unchanged in a mutant, cP51A, that has a severe ATP synthesis defect at high pH only. cP51 must have some structural role that accounts for the mutant defect, such as different subunit‐subunit interactions at high pH.
Hypoxia induces transcription of 6‐phosphofructo‐2‐kinase/fructose‐2,6‐biphosphatase‐4 gene via hypoxia‐inducible factor‐1α activation
Authors: Minchenko Oleksandr , Opentanova Iryna , Minchenko Dmytro , Ogura Tsutomu , Esumi Hiroyasu
Published: September 2004

The PFKFB4 gene encodes isoenzyme of 6‐phosphofructo‐2‐kinase/fructose‐2,6‐biphosphatase (PFKFB or PFK‐2/FBPase‐2) which originally was found in the testes. We have studied hypoxic regulation of PFKFB4 gene in prostate cancer cell line, PC‐3, and several other cancer cell lines. It was shown that hypoxia significantly induced PFKFB4 mRNA levels in PC‐3 as well as in HeLa, Hep3B and HepG2 cell lines. Hypoxia increased PFKFB4 protein levels also. Moreover, desferrioxamine and cobalt chloride, which are known to mimic hypoxia, also had a stimulatory effect on the expression of PFKFB4 mRNA. In order to investigate the mechanisms of hypoxic regulation of PFKFB4 gene expression, we used dimethyloxalylglycine, which has the ability to mimic effect of hypoxia by significant induction of hypoxia‐inducible factor (HIF‐1α) protein levels. Our studies showed that PFKFB4 mRNA expression in PC‐3, HeLa, Hep3B and HepG2 cell lines was highly responsive to dimethyloxalylglycine, an inhibitor of HIF‐1α hydroxylase enzymes, suggesting that the hypoxia responsiveness of this gene is regulated by HIF proteins. To better understand the hypoxic regulation of PFKFB4 gene expression, we isolated genomic DNA, which includes the promoter region of PFKFB4. Cell transfection, deletion and site‐specific mutagenesis of the PFKFB4 promoter region indicates that hypoxic induction of PFKFB4 gene expression is mediated by the hypoxia‐responsive element (HRE). These experiments identified a HRE 422–429 bp upstream from the translation start site. Thus, our results indicate that testis‐specific form of PFKFB or PFK‐2/FBPase‐2 is also expressed in several cancer cell lines and that hypoxia induces transcription of PFKFB4 gene in these cell lines by HIF‐1α dependent mechanism. HRE in 5′‐promoter region of PFKFB4 gene mediates hypoxic induction of PFKFB4 gene transcription.
Glycosylation of asparagines 136 and 184 is necessary for the α2δ subunit‐mediated regulation of voltage‐gated Ca2+ channels
Authors: Sandoval Alejandro , Oviedo Norma , Andrade Arturo , Felix Ricardo
Published: September 2004

The CaVα2δ auxiliary subunit is a glycosylated protein that regulates the trafficking and function of voltage‐gated Ca2+ channels. One of the most prominent roles of CaVα2δ is to increase whole‐cell Ca2+ current amplitude. Using N‐glycosidase F and truncated forms of CaVα2δ, earlier studies suggested an important role for N‐linked glycosylation in current stimulation. Here, we used site‐directed mutagenesis and heterologous expression in HEK‐293 cells to examine the impact of individual glycosylation sites within the CaVα2δ subunit on the regulation of Ba2+ currents through recombinant Ca2+ channels. We found two N‐glycosylation consensus sites (NX(S/T)) in the extracellular α2 domain of the protein that are functional. Substitution of asparagines for glutamines at amino acid positions 136 and 184 rendered these sites non‐functional as shown by patch‐clamp experiments. These results corroborate that N‐glycosylation is required for the CaVα2δ subunit‐induced current stimulation and suggest that sites N136 and N184 are directly involved in this action. Likewise, N136Q and N184Q mutations prevented whole‐cell current stimulation without altering its kinetic properties, suggesting a regulation on the number of functional channels at the plasma membrane.
N‐glycosylation at Asn491 in the Asn‐Xaa‐Cys motif of human transferrin
Authors: Satomi Yoshinori , Shimonishi Yasutsugu , Takao Toshifumi
Published: September 2004

Glycopeptides derived from human transferrin were exhaustively analyzed by matrix‐assisted laser desorption ionization and electrospray ionization mass spectrometry (MS). Both MS techniques clearly revealed the sequences of and the attachment sites of bi‐antennary complex‐type oligosaccharides, at both Asn432and Asn630, both of which are located in a well‐known motif for N‐glycosylation, Asn‐Xaa‐Ser/Thr, but also at Asn491in the Asn‐Xaa‐Cys motif. The latter has been reported to be a minor N‐glycosylation site in several glycoproteins. The relative abundance of this abnormal glycosylation was estimated to be approximately 2 mol% of the transferrin preparation used in this study.
Elsamicin A binding to DNA. A comparative thermodynamic characterization
Authors: Barceló Francisca , Portugal José
Published: September 2004

The antitumor drug elsamicin A contains a coumarin‐related chartarin chromophore that intercalates into DNA. It differs from other related molecules in its disaccharide moiety, which bears an amino sugar. Its binding to DNA was analyzed using isothermal titration calorimetry and UV thermal denaturation, and characterized thermodynamically. For the association of elsamicin A with DNA we found ΔG
∘=−8.6 kcal mol−1, ΔH=−10.4 kcal mol−1, ΔS=−6.1 cal mol−1 K
−1, and
K
obs=2.8(±0.2)×106 M−1 at 20 °C in 18 mM Na+. The contributions to the free energy of binding that lead to the DNA–elsamicin complex are compared with the binding to DNA of chartreusin, another chartarin‐containing drug. The results are discussed in terms of the contributions of the disaccharide moieties into the strength of binding.
The evolution of A‐, F‐, and V‐type ATP synthases and ATPases: reversals in function and changes in the H+/ATP coupling ratio
Authors: Cross Richard L. , Müller Volker
Published: September 2004

Members of the FoF1, AoA1 and VoV1 family of ATP synthases and ATPases have undergone at least two reversals in primary function. The first was from a progenitor proton‐pumping ATPase to a proton‐driven ATP synthase. The second involved transforming the synthase back into a proton‐pumping ATPase. As proposed earlier [FEBS Lett. 259 (1990) 227], these reversals required changes in the H+/ATP coupling ratio from an optimal value of about 2 for an ATPase function to about 4 for an ATP synthase function. The doubling of the ratio that occurred at the ATPase‐to‐Synthase transition was accomplished by duplicating the gene that encodes the nucleotide‐binding catalytic subunits followed by loss of function in one of the genes. The halving of the ratio that occurred at the Synthase‐to‐ATPase transition was achieved by a duplication/fusion of the gene that encodes the proton‐binding transporter subunits, followed by a loss of function in one half of the double‐sized protein. These events allowed conservation of quaternary structure, while maintaining a sufficient driving force to sustain an adequate phosphorylation potential or electrochemical gradient. Here, we describe intermediate evolutionary steps and a fine‐tuning of the H+/ATP coupling ratio to optimize synthase function in response to different environments. In addition, we propose a third reversal of function, from an ATPase back to an ATP synthase. In contrast to the first two reversals which required a partial loss in function, the change in coupling ratio required for the third reversal is explained by a gain in function.
Solution structure of coactosin reveals structural homology to ADF/cofilin family proteins
Authors: Hellman Maarit , Paavilainen Ville O. , Naumanen Perttu , Lappalainen Pekka , Annila Arto , Permi Perttu
Published: September 2004

Coactosin is a small (MW ∼15 kDa) evolutionarily conserved actin filament binding protein. It displays remote sequence homology to ADF/cofilin proteins and to the ADF‐H domains of twinfilin and Abp1/drebrin. However, biochemical analyses have demonstrated that coactosin has a very different role in actin dynamics from the ones of ADF/cofilin, twinfilin or Abp1/drebrin. To elucidate the molecular mechanism of coactosin/actin interaction, we determined the three‐dimensional structure of mouse coactosin by multidimensional NMR spectroscopy. We find that the coactosin structure is homologous to ADF/cofilin and to the ADF‐H domains of twinfilin. Furthermore, the regions that have been shown to be important for actin filament interactions in ADF/cofilins are structurally conserved in coactosin suggesting that these two proteins interact with F‐actin through a conserved interface. Our analysis also identifies key structural differences between these proteins that may account for the differences in biochemical activities and cellular roles of these proteins.
Quality of Nephrops as food for Atlantic cod (Gadus morhua L.) with possible implications for fisheries management
Authors: Björnsson Björn , Álvaro Dongala Dombaxe Maria
Published: September 2004

Nephrops was found to be of low quality as food for cod. In a laboratory experiment the mean specific growth rate of 1 kg cod was 0.184 and 0.415% d−1 when fed to satiation on Nephrops and capelin, respectively. This large difference in growth rate resulted not only from less intake of Nephrops (1.19 kg cod−1) than capelin (1.55 kg cod−1) but also because more Nephrops (4.6 kg) than capelin (2.2 kg) were required to produce each kilogramme of cod. Higher food conversion ratio was consistent with lower fat content of Nephrops (1.3%) than capelin (9.2%) but the exoskeleton also reduced the digestion rate of Nephrops. In the groups where Nephrops and capelin of equal mean weight were offered simultaneously, 40% of the diet consisted of Nephrops during the first week and 10% during the final seven weeks of the experiment. At the end of the experiment, condition factor, liver index, and gonadosomatic index were significantly lower for cod fed on Nephrops (0.967, 5.7, 7.1, respectively) than for those fed on capelin (1.086, 15.8, 11.2, respectively). These results suggests that predation by cod on Nephrops might be reduced by regular release of capelin or other similar food in the distributional areas of Nephrops.
Organic enrichment and structure of the macrozoobenthic community in the northern Adriatic Sea in an area facing Adige and Po mouths
Authors: Simonini R. , Ansaloni I. , Bonvicini Pagliai A.M. , Prevedelli D.
Published: September 2004

The structure of the macrozoobenthic community and the vertical distribution of organisms in the sediment were studied in order to assess the effects of river outflows and organic enrichment on the benthic community of the North Adriatic Sea. Sampling was carried out at one offshore sandy station (S3) and at two coastal muddy stations (S1 and S2), near to river Po and Adige deltas. Samples were collected in four surveys covering one year from April 1995 to January 1996. In all surveys, the offshore sandy station showed a complex trophic structure, high species richness and diversity, with the occurrence of tubicolous or burrowing polychaetes like Nothria conchylega, Aponuphis bilineata, Maldane sarsi, Nematonereis unicornis and Eunice vittata, which also colonized the deeper sediment layers. On the other hand, the coastal muddy stations both exhibited similar species composition and a great abundance of dominant, opportunistic species such as the bivalve Corbula gibba, typical of unstable sea bottoms with a high rate of sedimentation, and some polychaetes typical of sublittoral muddy bottoms such as Levinsenia gracilis, Aricidea claudiae, Prionospio malmgreni, Sternaspis scutata and P. cirrifera. The high density of a few opportunistic species (mainly surface-deposit feeders) and the scant penetration of organisms within sediments that characterized the stations S1 and S2 support other evidence of the eutrophication of the coastal areas of the north-western Adriatic Sea. However, the high biomass values, the species richness and diversity observed in S1 and S2 suggest the occurrence of less extreme conditions than at other highly-eutrophicated coastal areas. River outflows, eutrophication and, especially, the increasing frequency of acute dystrophic events may be recognized as the driving forces determining the structure and composition of the macrozoobenthic community at coastal areas of north-western Adriatic Sea.
Contrasting years in the Gironde estuary (Bay of Biscay, NE Atlantic) springtime outflow and consequences for zooplankton pyruvate kinase activity and the nutritional condition of anchovy larvae: an early view
Authors: Bergeron Jean-Pierre
Published: September 2004

A major spawning ground of the European anchovy (Engraulis encrasicolus) population in the Bay of Biscay is located near the mouth of the Gironde estuary. Variations in the river discharge affect the supply of nutrients to the coastal marine area encompassing anchovy spawning grounds. Two “Pegase” cruises (May–June 1997 and 1998) observed two contrasting situations: with and without a superficial layer of less saline water. Two new nutritional indices were used to assess potential effects (1) on carbohydrate assimilation rates by zooplankton estimated via pyruvate kinase (PK) activity measurements and (2) on nutritional condition of the anchovy larvae measured with the DNA/C index. Both indices indicated a much poorer situation in 1997 compared to 1998. Results of this study implicate river outflow rate as a potential factor influencing larval anchovy condition and perhaps to some extent recruitment variability.
Effects of experimentally‐induced anterior knee pain on knee joint position sense in healthy individuals
Authors: Bennell Kim , Wee Elin , Crossley Kay , Stillman Barry , Hodges Paul
Published: September 2004

Purpose. The ability to sense the position of limb segments is a highly specialised proprioceptive function important for control of movement. Abnormal knee proprioception has been found in association with several musculoskeletal pathologies but whether nociceptive stimulation can produce these proprioceptive changes is unclear. This study evaluated the effect of experimentally induced knee pain on knee joint position sense (JPS) in healthy individuals.

Study design. Repeated measures, within‐subject design.

Methods. Knee JPS was tested in 16 individuals with no history of knee pathology under three experimental conditions: baseline control, a distraction task and knee pain induced by injection of hypertonic saline into the infrapatellar fat pad. Knee JPS was measured using active ipsilateral limb matching responses at 20° and 60° flexion whilst non‐weightbearing (NWB) and 20° flexion single leg stance. During the tasks, the subjective perception of distraction and severity of pain were measured using 11‐point numerical rating scales.

Results. Knee JPS was not altered by acute knee pain in any of the positions tested. The distraction task resulted in poorer concentration, greater JPS absolute errors at 20° NWB, and greater variability in errors during the WB tests. There were no significant correlations between levels of pain and changes in JPS errors. Changes in JPS with pain and distraction were inversely related to baseline knee JPS variable error in all test positions (r = −0.56 to −0.91) but less related to baseline absolute error.

Conclusion. Knee JPS is reduced by an attention‐demanding task but not by experimentally induced pain. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Endoscopic Treatment of Benign Tumors of the Nose and Paranasal Sinuses
Authors: Pasquini Ernesto , Sciarretta Vittorio , Frank Giorgio , Cantaroni Cosetta , Modugno Giovanni Carlo , Mazzatenta Diego , Farneti Giovanni
Published: September 2004

OBJECTIVE

The endoscopic approach can be successfully employed for the treatment of benign tumors such as fibroosseus and vascular lesions, pleomorphic adenomas, gliomas, and schwannomas.

STUDY DESIGN AND SETTING

Nineteen patients diagnosed with benign tumors of the nasal cavity and paranasal sinuses and treated using an endoscopic approach were retrospectively reviewed. The endoscopic approach was used exclusively in 15 cases and was associated with an external approach in 4 cases (due to an intracranial extension of the tumor in 3 patients and its location at the level of the anterior wall of the frontal sinus in the last case).

RESULTS

The resection of the lesions was radical in 18 patients and subtotal in 1 case. The mean follow‐up was 27 months and only 1 recurrence (5%) was observed in the juvenile angiofibroma group 20 months postoperatively.

CONCLUSION AND SIGNIFICANCE

In selected cases, endoscopic surgery can be considered an effective treatment for the resection of benign tumors involving the sinonasal tract.
Surgical Classification of Variations in the Anatomy of the Sigmoid Sinus
Authors: Sarmiento Pedro Blanco , Eslait Francisco Gonzalez
Published: September 2004

OBJECTIVE

Analyze the variability of anatomic relations between the sigmoid sinus and other surgical landmarks within the mastoid cavity to establish a classification of sinus location to facilitate surgical planning.

STUDY DESIGN

A descriptive study of surgical landmarks using 96 temporal bones from the Temporal Bone Laboratory at the Department of Otorhinolaryngology, Valle University at Cali, Colombia.

METHODS

A dissection simulating a canal wall‐up mastoidectomy extended to include exposure of the facial recess, epitympanum, and sigmoid sinus was performed on 96 adult disease‐free temporal bones. Seven standard measurements were taken on each bone between the sigmoid sinus and other structures in the mastoid cavity. All data were analyzed using Epi‐Info 2000.

RESULTS

This parametric study was consistent with three classes of anatomic variations in the location of the sigmoid sinus (type 1, type 2, and type 3) based on a Gaussian distribution of the seven variables.

CONCLUSIONS

Variability in the anatomic location of the sigmoid sinus in the mastoid cavity is common and has surgical relevance.

SIGNIFICANCE

This classification will help to rapidly identify the sigmoid sinus relationship within the mastoid cavity and to use the sigmoid sinus as a landmark during ear surgery in those cases in which traditional landmarks, such as the posterior auditory canal wall or the semicircular canals, are destroyed by a pathologic process.
Sclerotherapy for Congenital Lesions in the Head and Neck
Authors: Kim Kwang Hyun , Sung Myung‐Whun , Roh Jong‐Lyel , Han Moon Hee
Published: September 2004

OBJECTIVES

This study retrospectively reviews the results of sclerotherapy using several sclerosants for congenital lesions of the head and neck.

METHODS AND PATIENTS

Between May 1990 and May 2002, patients with lymphatic malformations were treated by sclerotherapy; 10 with bleomycin, and 25 with OK‐432. OK‐432 sclerotherapy was also applied in 9 patients with plunging ranula and in 1 patient with branchial anomaly. Percutaneous sclerotherapy with ethanolamine oleate was used in 29 patients with venous malformations, and 28 patients with pyriform sinus fistula were treated by trichloroacetic acid chemocauterization.

RESULTS

Overall, two thirds of patients with these lesions showed marked to complete response. One case of mortality occurred in the bleomycin sclerotherapy group. However, no major complications by other sclerosants were found. In lymphatic malformations, history of excision before sclerotherapy was a poor prognostic factor.

CONCLUSION

Sclerotherapy using these sclerosants is a safe and effective primary treatment for congenital lesions in the head and neck.
The Usefulness of Cytokeratin Immunohistochemistry in Detection of Lymph Node Micrometastasis in Neck Dissection Specimens
Authors: Kwon Soon‐Young , Kim Hyung‐Jin , Woo Jeong‐Su , Jung Kwang‐Yoon , Kim Insun
Published: September 2004

OBJECTIVE

Our study was designed to find out the rate and the characteristics of micrometastasis in cervical lymph nodes using immunohistochemical staining.

STUDY DESIGN AND SETTING

From 69 patients, 1710 lymph nodes negative for metastasis on hematoxylin‐eosin stain, were examined. Immunohisto‐chemical stain was performed using pan‐cytokeratin AE1/AE3 antibody.

RESULTS

In 13 cases, occult lymph node metastasis was detected by immunohistochemical method. On retrospective review of the hematoxylin‐eosin stain by the pathologist, lymph node metastasis was detected in 4 of 13 patients.

CONCLUSIONS

Because the immunohistochemical method enhanced the detection rate of occult micrometastasis in cervical lymph nodes of head and neck squamous cell carcinoma patients, it may be recommended for routine diagnostic use in patient with negative for a lymph node metastasis on routine hematoxylin‐eosin stain.
Advances in Congenital Aural Atresia Surgery: Effects on Outcome
Authors: Teufert Karen Borne , De La Cruz Antonio
Published: September 2004

OBJECTIVES

To compare modifications in the surgical technique of congenital aural atresia (use of argon laser, thinner split‐thickness skin graft, Silastic sheets in the external auditory canal, and Merocel wicks) by examining hearing results and complications before and after initiation of these changes.

STUDY DESIGN AND SETTING

Retrospective chart review of patients who underwent congenital aural atresiaplasty between 1985 and 2002 in a tertiary referral neurotologic private practice. Complication rates and hearing results were compared before (n = 36) and after (n = 80) modifications in the surgical technique.

RESULTS

Closure of the air‐bone gap to 30 dB or less at short‐term follow‐up occurred in 63.1% of surgeries performed after modifications in the surgical technique and 44.5% of surgeries performed before these changes. The long‐term postoperative air‐bone gap was 30 dB or less in 50.0% of the surgeries performed after and 47.1% of the cases performed before the changes in surgical technique. Soft tissue stenosis and bony growth of the external auditory canal were seen in 3.8% of surgeries performed after and 13.9% of surgeries performed before the surgical technique changes. Ossicular chain refixation occurred in 3.8% of surgeries performed after and 25.0% of surgeries performed before such changes. There were no dead ears and no facial palsies.

CONCLUSION

The use of argon laser, thinner split‐thickness skin graft, Silastic sheets in the external auditory canal, and Merocel wicks, as a group, has helped to improve hearing results and decrease the incidence of complications in congenital aural atresia surgery.

SIGNIFICANCE

Refinements in surgical techniques can lead to measurable improvements in outcome in atresiaplasty.
Impact of Image Guidance on Complications During Osteoplastic Frontal Sinus Surgery
Authors: Sindwani Raj , Metson Ralph
Published: September 2004

OBJECTIVES

To evaluate the impact of image‐guidance technology on intraoperative complications during frontal sinus obliteration surgery.

STUDY DESIGN AND SETTING

Retrospective case control. Twenty‐four patients underwent frontal sinus obliteration with image‐guidance technology (n = 15) or conventional instrumentation (n = 9) between 1992 and 2003. The image‐guidance system was used to delineate the frontal sinus perimeter and direct cuts through the frontal bone.

RESULTS

Intraoperative complications occurred in none of the patients in the image‐guidance group and in 3 patients in the control group (P = 0.042). Adverse events included dural tear with CSF leak in 2 patients and exposure of orbital fat in 1 patient. The incidence of postoperative complications was similar between groups (P = 0.326). No patients required revision surgery. Mean follow‐up was 5.2 years.

CONCLUSIONS

The use of surgical navigation during frontal sinus obliteration appears to improve intraoperative safety.

SIGNIFICANCE

This is the first report to document a reduction in the rate of intraoperative complications when image guidance is utilized for frontal sinus surgery.
Late Holocene δ13C and pollen records of paleosalinity from tidal marshes in the San Francisco Bay estuary, California
Authors: Malamud-Roam Frances , Lynn Ingram B.
Published: September 2004

Records of stable carbon isotopes (δ13C) are presented from cores collected from four San Francisco Bay marshes and used as a proxy for changes in estuary salinity. The δ13C value of organic marsh sediments are a reflection of the relative proportion of C3vs. C4plants occupying the surface, and can thus be used as a proxy for vegetation change on the marsh surface. The four marshes included in this study are located along a natural salinity gradient that exists in the San Francisco Bay, and records of vegetation change at all four sites can be used to infer changes in overall estuary paleosalinity. The δ13C values complement pollen data from the same marsh sites producing a paleoclimate record for the late Holocene period in the San Francisco Bay estuary. The data indicate that there have been periods of higher-than-average salinity in the Bay estuary (reduced fresh water inflow), including 1600–1300 cal yr B.P., 1000–800 cal yr B.P., 300–200 cal yr B.P., and ca. A.D. 1950 to the present. Periods of lower-than-average salinity (increased fresh water inflow) occurred before 2000 cal yr B.P., from 1300 to 1200 cal yr B.P. and ca. 150 cal yr B.P. to A.D. 1950. A comparison of the timing of these events with records from the California coast, watershed, and beyond the larger drainage of the Bay reveals that the paleosalinity variations reflected regional precipitation.
U-Series dating of locality 15 at Zhoukoudian, China, and implications for hominid evolution
Authors: Shen Guanjun J. , Gao Xing , Zhao Jian-xin , Collerson Kenneth D.
Published: September 2004

This paper reports U-series dates on speleothem samples from Locality 15 at Zhoukoudian, one of the richest Paleolithic sites in northern China. The age of the lower part of Layer 2 is securely bracketed between 155,000 and 284,000 yr. The underlying Layer 3 dates back at least 284,000 yr. Layer 4, further below, should be older still, possibly by a cycle on the SPECMAP time scale before 284,000 yr ago. These ages, much greater than the previous estimates of 110,000"140,000 yr from U-series and electron spin resonance dating of fossil teeth, suggest that Locality 15 was broadly contemporaneous with Locality 4 (New Cave) and with the uppermost strata of Locality 1 (Peking Man site). The physical evolution and cultural development evidenced by the timing of the Zhoukoudian localities are in line with the opinion of Chinese anthropologists for a regional transition from Homo erectus to archaic Homo sapiens.