bluuebunny/crossref_metadata_2025 huggingface dataset:
A method for interleaved acquisition of a vascular input function for dynamic contrast‐enhanced MRI in experimental rat tumours
Authors: McIntyre Dominick J. O. , Ludwig Christian , Pasan Amit , Griffiths John R.
Published: May 2004

Dynamic contrast‐enhanced MRI is widely used for the evaluation of the response of experimental rodent tumours to antitumour therapy, particularly for the newly developing antiangiogenic and antivascular agents. However, standard models require a time‐course for the plasma concentration of contrast agent (usually referred to as the arterial input function) to calculate the transfer constant Ktrans from the dynamic time‐course data. Ideally, the plasma concentration time‐course should be measured during each experiment to obtain the most accurate measure of Ktrans. This is technically difficult in rodents, so assumed values are generally used. A method is presented here using interleaved acquisitions from a tail coil to obtain the plasma concentration simultaneously with DCE‐MRI data obtained from a solenoid coil around the tumour. The SNR of the resulting vascular input function data is high compared with methods using a volume coil to acquire plasma concentrations from the aorta and vena cava. Copyright © 2004 John Wiley & Sons, Ltd.
Fluoropyrimidine chemotherapy in a rat model: comparison of fluorouracil metabolite profiles determined by high‐field 19F‐NMR spectroscopy of tissues ex vivo with therapy response and toxicity for locoregional vs systemic infusion protocols
Authors: Lutz Norbert W. , Naser‐Hijazi Belal , Koroma Squire , Berger Martin R. , Hull William E.
Published: May 2004

A Sprague–Dawley rat model with DS sarcoma transplanted in the thigh was used to compare transcatheter locoregional i.a. and systemic i.v. administration of 5‐fluorouracil (FU) at 12 dose‐rate schedules: 25, 50 and 100 mg/kg; bolus, 1, 5 and 24 h infusions. In experiment A tumor (62/67 animals) as well as liver and kidney (56/67 animals) were excised 1 h after a single bolus or 1 h infusion or at the end of 5 and 24 h infusions. 19F‐NMR spectroscopy at 11.7 T was used to quantitate FU and its metabolites in ca. 1 g of tissue at 4°C. In experiment B analogous FU treatments were repeated for 5 days (rats 80+11 controls). Tumor volumes vs time, various blood parameters and survival times were recorded, and a log growth rate parameter log GR, a response index RI, and a toxicity index TI were calculated. The i.a. vs i.v. ratios for tumor concentrations of FU and total anabolites (F‐Nucl) were >1 for nearly all treatments and increased with infusion time at the higher doses. F‐Nucl in tumor correlated linearly with total fluorine concentration (Tot. F range 30–1100 nmol/g) over all treatments (r=0.92, slope=0.45, p<0.0001). For non‐bolus i.v. treatments [FU+F‐Nucl] decreased linearly with decreasing FU dose rate (r2=0.74, zero intercept), while i.a. treatments showed non‐linear behavior. For non‐bolus treatments the mean log GR per treatment group showed a negative correlation (r=−0.87) with log[F‐Nucl]. The most effective non‐toxic treatments were 25 mg/kg over 5 or 24 h; the i.a. route was superior to i.v. on the basis of [FU+F‐Nucl], RI, the reduction in log GR, and Kaplan–Meier survival statistics. For liver and kidney Tot. F (>83% FU catabolites) reached ca. 3–4 and 6–7 μmol/g, respectively, at the highest dose rates for either route; F‐Nucl were detected only for Tot. F>500 nmol/g and increased exponentially as Tot. F increased (toxic treatments). The concentrations of the main catabolite (α‐fluoro‐β‐alanine, FBAL) in tumor did not correlate with Tot. F but rather with FBAL levels in kidney (r=0.90, all treatments), indicating that uptake of liver‐derived FBAL from the circulation is the major source of FBAL in tumor. Copyright © 2004 John Wiley & Sons, Ltd.
SNMP for home automation
Authors: Giladi Ran
Published: May 2004

Home and building automation applications impose the need for convergence, or at least interoperability, of data networks with intelligent building networks. This situation entails the use of a unified management system. In this paper we extend the traditional SNMP‐based network management system paradigm by creating an integrated site network management system that contains data elements, telecommunication equipment and intelligent building devices. A possible architecture based on a proxy gateway is presented and analyzed. We suggest an implementation and potential applications. Copyright © 2004 John Wiley & Sons, Ltd.
A new approach to ensure fairness over the Internet
Authors: Salim Zabir Salahuddin Muhammad , Ashir Ahmed , Kitagata Gen , Shiratori Norio
Published: May 2004

Congestion signaling is an essential issue for ensuring a high network performance. Explicit congestion notification (ECN) has been proved to provide a faster indication of congestion and thus improve the QoS of a TCP/IP network. In this paper, we present a new scheme for ECN named fair in‐time marking (FIM), which employs a mechanism that as well as providing an indication of incipient congestion, assures a fair service to all the connections. To facilitate such services using FIM, we propose inclusion of some simple yet effective functionalities in the routers. This is important as the client base of the Internet is increasing rapidly and the demand for a reasonably fair service is getting stronger. Experiments show that FIM offers the best fairness, sometimes better by around 20% or more without affecting efficiency, compared with other proposed schemes for ECN. Copyright © 2004 John Wiley & Sons, Ltd.
Favorable response to soft tissue sarcoma therapy in an adolescent with embryonal renal sarcoma
Authors: Hummel Trent , Hord Jeffrey D.
Published: May 2004

Embryonal renal sarcomas were first identified in 1995 among banked tumor samples originally classified as adult Wilms tumor. Few long‐term remissions were observed when these rare tumors were treated with chemotherapy usually used for childhood Wilms. Data were collected from the medical record of an adolescent female with embryonal renal sarcoma and treated with sarcoma‐directed chemotherapy and radiation. At 66 months following diagnosis, the patient has no evidence of tumor but has experienced severe renal dysfunction and ovarian failure. We believe there is a subset of patients with disseminated embryonal renal sarcoma that respond to intense sarcoma‐directed therapy. © 2004 Wiley‐Liss, Inc.
Plasticized microporous poly(vinylidene fluoride) separators for lithium‐ion batteries. III. Gel properties and irreversible modifications of poly(vinylidene fluoride) membranes under swelling in liquid electrolytes
Authors: Saunier J. , Alloin F. , Sanchez J. Y. , Maniguet L.
Published: May 2004

Microporous poly(vinylidene fluoride) (PVdF) separators for lithium‐ion batteries, used in liquid organic electrolytes, have been characterized with respect to the swelling phenomena on dense PVdF membranes (obtained through hot pressing). In the first and second parts of this study, we have described the swelling equilibria and swelling kinetics of dense PVdF. Here the thermal properties of PVdF gels and their irreversible modifications induced by swelling are characterized. Particular attention is paid to crystallinity modifications, polymer plasticization, and membrane degradation. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2308–2317, 2004
Changes in the near‐edge X‐ray absorption fine structure spectra of long‐chain diacetylene derivatives through photopolymerization in Langmuir–Blodgett films
Authors: Fujimori Atsuhiro , Ishitsuka Mikako , Nakahara Hiroo , Ito Eisuke , Hara Masahiko , Kanai Kaname , Ishii Hisao , Ouchi Yukio , Seki Kazuhiko
Published: May 2004

Photopolymerization of cadmium 10,12‐pentacosadiynoate (CdDA) in Langmuir–Blodgett (LB) films, with the molecular packing well arranged by moderate preannealing, was investigated with near‐edge X‐ray absorption fine structure (NEXAFS) spectroscopy. Greenish films of polydiacetylene with an absorption wavelength of 705 nm were obtained through the photopolymerization of preannealed monomer LB films, and this resulted in an extended π‐conjugate system based on the well‐ordered monomer in a two‐dimensional arrangement. The electronic structures of the polydiacetylenes were found to be correlated to the variation of the molecular arrangements in the films from the changes in the NEXAFS spectra through photopolymerization in the LB films. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2329–2336, 2004
Split and sealing of dislocated pipes at the front of a growing crystal
Authors: Gutkin M. Yu. , Sheinerman A. G.
Published: May 2004

A model is suggested for the split of dislocated pipes at the front a growing crystal. Within the model, the pipe split occurs through the generation of a dislocation semi‐loop at the pipe and crystal surfaces and its subsequent expansion into the crystal interior. The strain energy of such a dislocation semi‐loop as well as the stress field of a dislocated pipe perpendicular to a flat crystal surface are calculated. The parameter regions are determined at which the expansion of the dislocation semi‐loop is energetically favorable and, thus, the pipe split becomes irreversible. A mechanism is proposed for the formation of a stable semi‐loop resulting in the split and possible subsequent overgrowth of the dislocated pipe. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ferroelectric relaxor behaviour of Na0.5Bi0.5TiO3–SrTiO3 ceramics
Authors: Gomah‐Pettry J. R. , Salak A. N. , Marchet P. , Ferreira V. M. , Mercurio J. P.
Published: May 2004

The dielectric properties of (Na0.5Bi0.5)xSr1−xTiO3 (0 ≤ x ≤ 0.2) ceramic materials were studied from 10 to 300 K between 100 Hz and 1 MHz. At low substitution rates (0 ≤ x ≤ 0.02), two thermally activated relaxation modes were observed and attributed to non interacting dipoles. For x > 0.02, the highest temperature mode, independent on the composition, remains but its intensity decreases and eventually vanishes for x = 0.20. In addition the observed strong dispersion of the permittivity was connected with a relaxor behaviour the origin of which being due to the increasing density of interacting dipoles or dipole clusters. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quantum and transport lifetimes of a two‐dimensional hole gas in the presence of spin–orbit interaction
Authors: Xu W. , Vasilopoulos P. , Wang X. F.
Published: May 2004

We present a simple theoretical approach for evaluating the spin‐dependent carrier distribution as well as quantum and transport lifetimes in a two‐dimensional hole gas (2DHG) in the presence of spin–orbit interaction (SOI) induced by the Rashba effect. For low temperatures and over a wide range of the sample parameters, the SOI can enhance the mobility of the sample system and the quantum and transport lifetimes of a 2DHG due to background‐impurity scattering do not differ significantly between different spin branches. These are mainly due to the unique features of the hole‐impurity scattering in the presence of the SOI. A small difference of the quantum lifetimes in different spin branches has been observed experimentally in spin‐split two‐dimensional electron gas systems. Our results indicate that this interesting observation can be made in spin‐split 2DHGs as well. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sonographic imaging of cervical scars after Cesarean section
Authors: Zimmer E. Z. , Bardin R. , Tamir A. , Bronshtein M.
Published: May 2004

Objective

To investigate whether uterine contractions at the time of a Cesarean section have an impact on future presence and location of a cervical Cesarean scar.

Methods

A targeted transvaginal ultrasound examination of the fetus, uterus and cervix was done in 2973 consecutive women at 14–16 weeks' gestation. The sonographer was blinded to the women's previous obstetric histories. The presence and location of a sonographic cervical hypoechogenic line, which probably represented a Cesarean scar, was recorded.

Results

There were 180 women with a previous Cesarean section performed before the start of uterine contractions and 173 with a Cesarean section performed during contractions in labor. The cervical hypoechogenic line was more common in sections performed during contractions (75.7% vs. 52.7%; P < 0.001) and was more distally located from the internal os (17.9 ± 9.4 vs. 14.6 ± 9.1 mm; P = 0.01). A hypoechogenic line was observed in 21/2620 women without a previous Cesarean section, representing a false‐positive rate of 0.8%.

Conclusion

Cesarean sections, especially those done during uterine contractions, are actually performed through cervical tissue. This finding is in agreement with the physiological process of cervical effacement during contractions. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Prenatal diagnosis of intrauterine premature closure of the ductus arteriosus following maternal diclofenac application
Authors: Auer M. , Brezinka C. , Eller P. , Luze K. , Schweigmann U. , Schwärzler P.
Published: May 2004

We report a case of prenatal diagnosis of premature closure of the ductus arteriosus following maternal diclofenac therapy at 35 weeks of gestation. Fetal echocardiography at 37 weeks of gestation revealed a dilated right ventricle with moderate tricuspid regurgitation, pulmonary insufficiency and complete closure of the ductus arteriosus. Immediate Cesarean section resulted in an excellent neonatal outcome. Whereas the effect of indomethacin on prenatal ductal constriction is well known, widely prescribed non‐steroidal anti‐inflammatory drugs such as diclofenac can have an equally deleterious effect and are best avoided in the third trimester of pregnancy. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Predicting the severity of fetal anemia using time‐domain measurement of volume flow in the fetal aorta
Authors: Harrington K. , Fayyad A. , Nicolaides K. H.
Published: May 2004

Objectives

To assess the value of fetal aortic time‐domain measurement of volume flow (using color velocity imaging quantification (CVI‐Q)) in predicting the severity of fetal anemia.

Methods

This was a prospective observational study, in which 24 pregnant women with suspected fetal anemia due to rising anti‐red blood cell antibody titers underwent cordocentesis. The fetal aortic time‐domain volume flow was measured before fetal blood sampling for fetal hemoglobin investigation. We examined the correlation between increased fetal aortic time‐domain volume flow (>2 SD for gestational age) and fetal anemia (hemoglobin level <2 SD for gestational age).

Results

Seventeen fetuses had anemia, and seven had normal hemoglobin. There was a strong correlation between the increase in fetal aortic time‐domain volume flow and the drop in hemoglobin value (r = 0.81; P < 0.01). The sensitivity of this technique to predict fetal anemia was 81.3% and the specificity was 71.4%. The mean increase over time in aortic CVI‐Q in anemic fetuses was 323.2 mL/min (95% CI, 200.1 to 446.4) compared with 86.9 mL/min (95% CI, −17.7 to 191.5) in the non‐anemic group (P = 0.004).

Conclusion

Fetal aortic time‐domain measurement of volume flow is significantly increased in cases of fetal anemia due to red‐cell alloimmunization. These findings can be used to improve the sensitivity, specificity and positive predictive value of the non‐invasive techniques used to predict fetal anemia, and may help in the selection of pregnancies that require cordocentesis and transfusion. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Early prenatal diagnosis by celocentesis
Authors: Makrydimas G. , Georgiou I. , Bouba I. , Lolis D. , Nicolaides K. H.
Published: May 2004

Background

Celocentesis is the ultrasound‐guided aspiration of fluid from the extra‐amniotic cavity at 7–8 weeks of gestation. This paper reports on the clinical application of celocentesis for early prenatal diagnosis.

Methods

Celocentesis was successfully performed in nine pregnancies and 1–2 mL of fluid were obtained after one needle insertion. The indications were prenatal diagnosis of β‐thalassemia or sickle cell disease (n = 6), Marfan syndrome (n = 1) and paternity testing (n = 2). Molecular biological techniques were used to analyze the celomic fluid and this was successfully carried out in all cases.

Results

In two cases pregnancy termination was performed at the request of the mother because in one case the fetus was found to have sickle cell anemia and in the second case paternity testing demonstrated that the father was not the woman's husband. In both cases the results were confirmed using the placental samples collected after pregnancy termination. In six of the seven pregnancies with desirable results, amniocentesis was performed at 16 weeks and the results were concordant with those obtained from celocentesis. All pregnancies were uneventful and resulted in the delivery of healthy and appropriately grown babies.

Conclusion

Celocentesis may be a viable alternative to the currently used tests of chorionic villus sampling and amniocentesis. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Comparison of pregnancy outcome of euploid fetuses with increased nuchal translucency (NT) expressed in NT MoM or delta‐NT
Authors: Maymon R. , Tercanli S. , Dreazen E. , Sartorius G. , Holzgreve W. , Herman A.
Published: May 2004

Objective

To evaluate the outcome of euploid fetuses with increased nuchal translucency thickness (NT) expressed in multiples of the median (MoM) or delta‐NT.

Methods

Included in the study were euploid fetuses with increased NT ≥ 95th centile, for which information about pregnancy outcome was available. The following parameters were defined as an adverse outcome: miscarriage, structural anomalies justifying termination of pregnancy, and structural anomalies, genetic syndromes and neurodevelopmental problems diagnosed postnatally. Fetal outcome according to NT MoM and delta‐NT was calculated using different cut‐off values. Calculations of the odds ratio for adverse outcome were performed using either NT MoM or delta‐NT as a predictor in logistic regression models.

Results

The study comprised 168 euploid fetuses. Of these, 38 (23%) had an adverse outcome: 11 (6%) had miscarriages, 14 (8%) were terminated because of fetal abnormalities detected on the prenatal scan and 13 (7%) were found postnatally to have abnormalities. The incidence of cases exhibiting an adverse outcome was 5.3%, 19.2% and 58.5% for NT values of 1.6–1.9, 2.0–3.0 and >3.0 MoM, respectively (P < 0.0001, χ2 test), and 3.9%, 16.7% and 62.8% for delta‐NT values of 1.0–1.4, 1.5–2.5 and >2.5 mm, respectively (P < 0.0001, χ2 test). Using cut‐offs of 2.0 MoM and delta‐NT of 1.5 mm, the odds ratios for adverse outcome were 10.2 (95% CI, 3.4–30.4) and 15.4 (95% CI, 4.2–43.6), respectively.

Conclusion

Both the NT MoM and delta‐NT approaches may be used to determine cases which require additional antenatal investigation as well as fetal karyotyping. For this purpose we suggest using a cut‐off of either 2.0 MoM or a delta‐NT of 1.5 mm. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
An assertional proof for a construction of an atomic variable
Authors: Hesselink Wim H.
Published: May 2004

The paper proves by assertional means the correctness of a construction of Haldar and Subramanian of an atomic shared variable for one writer and one reader. This construction uses four unsafe variables and four safe boolean variables. Assignment to a safe but nonatomic variable is modelled as a repetition of random assignments concluded by an actual assignment. The proof obligation consists of four invariants. These are proved using 25 auxiliary invariants. The proof has been constructed and verified with the theorem prover NQTHM.
Effect of Pharmacologic Preconditioning with Tetrandrine on Subsequent Ischemia/Reperfusion Injury in Rat Liver
Authors: Liu Zhongmin , Xu Zhenping , Shen Wenlu , Li Yi , Zhang Jun , Ye Xin
Published: May 2004

The effect of tetrandrine (TET) pretreatment of Wistar rats subjected to warm hepatic ischemia/reperfusion (I/R) was investigated. After 50 minutes of ischemia in the left and median lobes of the liver and 24 hours of reperfusion (I/R group), the rats were killed. The TET+I/R group rats were pretreated with TET (50 mg/kg body weight IP) 30 minutes prior to the onset of ischemia. Blood samples were taken for measurement of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH). Tissue was taken from the ischemic lobes for measurement of superoxide dismutase (SOD), malonyldialdehyde (MDA), and myeloperoxidase (MPO); determination of the wet/dry weight (W/D) ratio; and histologic studies. The results showed that ALT, AST, and LDH levels in serum were increased in the I/R group; tissue MDA generation, MPO activity, and the W/D ratio were also increased, accompanied by decreased SOD activity. The serum ALT, AST, and LDH levels, as well as the tissue MPO level and W/D ratio, were lower in the TET+I/R group than in the I/R group; and the SOD level was higher in the TET+IR group than in the I/R group. Moreover, the serum ALT and AST, tissue MDA, and W/D ratio in the TET+I/R group were higher, and the SOD was lower than in the sham group. The histologic examination showed protection against liver damage in the TET+I/R group. The results demonstrated that pretreatment with TET could somewhat protect the liver against I/R injury but does not prevent it. The simultaneous decrease of both lipid peroxide generation and polymorphonuclear neutrophil infiltration in the ischemic liver may explain the acquisition of tolerance following administration of TET.
Do Young Colon Cancer Patients Have Worse Outcomes?
Authors: O’Connell Jessica B. , Maggard Melinda A. , Liu Jerome H. , Etzioni David A. , Livingston Edward H. , Ko Clifford Y.
Published: May 2004

Previous studies on colon cancer have noted rising incidence rates among young individuals and suggest that they may have more aggressive disease and worse 5‐year survivals than their older counterparts. Our study uses a nationwide population‐based cancer registry to analyze colon cancer presentations and outcomes in a young versus an older population. The records of patients with colon carcinoma were obtained from the Surveillance, Epidemiology, and End Results (SEER) national cancer database (1991–1999). Two cohorts based on age at diagnosis (20–40 years, n = 1334 vs. 60–80 years, n = 46,457) were compared for patient and tumor characteristics, treatment, and 5‐year cancer‐specific survival. A multivariate Cox regression was performed to identify predictors of survival. The young group had a higher proportion of black and Hispanic patients than did the older group (p < 0.001). Young patients had less stage I or II disease, more stage III or IV disease (p < 0.001), and worse‐grade (poorly differentiated or anaplastic) tumors (p < 0.001). The 5‐year stage‐specific survival was similar for stage I and III disease (p = NS) but was significantly better for young patients with stage II and IV disease (p < 0.01). Using a nationally representative cancer registry, we found that young colon cancer patients tend to have later‐stage and higher‐grade tumors. However, they have equivalent or better 5‐year cancer‐specific survival compared to older patients. This population‐based finding contradicts prior single‐institution reports.
Galen on Obesity: Etiology, Effects, and Treatment
Authors: Papavramidou Niki S. , Papavramidis Spiros T. , Christopoulou‐Aletra Helen
Published: May 2004

Only a few studies have been conducted to determine the historical background of obesity, and even fewer have focused on specific writers who have made great contributions on the subject. Galen was among the first to establish scientific methods to describe and treat morbid obesity, and a presentation of his ideas is important because of the influence he has exerted even up to modern times. The methodology of the current research was based on detailed study of Galen’s treatises, which concern the nature of obesity, the etiology, the consequences, and the treatment, often in comparison to the writings of other writers from the Hippocratic period up to recent years. Galen stated that obesity results from the surplus of “bad humors” in the body and specifically from a surplus of blood. He specifically described patients’ conditions, both physiologic and practical; he presented side effects; and he introduced methods of treatment that are used even today. Galen also described an illness he called polisarkia, which today we call morbid obesity. According to Galen’s views, we can identify morbid obesity under the description of polisarkia. Galenic physiology and pathology have been proved wrong and have been set aside. Nevertheless, he proposed some treatments for obesity such as diet, exercise, and medications that are still valuable and are nearly the same as what is advocated today.
Regulatory SNPs in complex diseases: their identification and functional validation
Authors: Prokunina Ludmila , Alarcón-Riquelme Marta E.
Published: May 2004

Finding the genetic causes for complex diseases is a challenge. Expression studies have
shown that the level of expression of many genes is altered in disease compared
with normal conditions, but what lies behind these changes? Linkage studies
provide hints as to where in the genome the genetic triggers – the mutations
– might be located. Fine-mapping and association studies can give yet more
information about which genes, and which changes in the genes, are involved
in the disease. Recent examples show that single-nucleotide polymorphisms (SNPs),
which are variations at the single-nucleotide level within an individual's
DNA, in the regulatory regions of some genes constitute susceptibility factors
in many complex diseases. This article discusses the nature of regulatory SNPs
(rSNPs) and techniques for their functional validation, and looks towards what
rSNPs can tell us about complex diseases.
Development of a fermentation system to model sessile bacterial populations in the human colon
Authors: Probert H. M. , Gibson G. R.
Published: May 2004

A fermentation system was designed to model the human colonic microflora in vitro. The system provided a framework of mucin beads to encourage the adhesion of bacteria, which was encased within a dialysis membrane. The void between the beads was inoculated with faeces from human donors. Water and metabolites were removed from the fermentation by osmosis using a solution of polyethylene glycol (PEG). The system was concomitantly inoculated alongside a conventional single-stage chemostat. Three fermentations were carried out using inocula from three healthy human donors.

Bacterial populations from the chemostat and biofilm system were enumerated using fluorescence in situ hybridization. The culture fluid was also analysed for its short-chain fatty acid (SCFA) content. A higher cell density was achieved in the biofilm fermentation system (taking into account the contribution made by the bead-associated bacteria) as compared with the chemostat, owing to the removal of water and metabolites. Evaluation of the bacterial populations revealed that the biofilm system was able to support two distinct groups of bacteria: bacteria growing in association with the mucin beads and planktonic bacteria in the culture fluid. Furthermore, distinct differences were observed between populations in the biofilm fermenter system and the chemostat, with the former supporting higher populations of clostridia and Escherichia coli. SCFA levels were lower in the biofilm system than in the chemostat, as in the former they were removed via the osmotic effect of the PEG. These experiments demonstrated the potential usefulness of the biofilm system for investigating the complexity of the human colonic microflora and the contribution made by sessile bacterial populations.
The influence of light and temperature interactions on a natural estuarine microphytobenthic assemblage
Authors: Defew E. C. , Perkins R. G. , Paterson D. M.
Published: May 2004

A natural microphytobenthic assemblage from the Eden Estuary, Scotland, was used to study the effect of temperature and irradiance on the sustainability and species composition of a natural transient biofilm. Three tidal tanks were maintained: tank 1 at 10 °C; tank 2 at 18 °C; and tank 3 at 26 °C. Within each tank, five cores were unshaded (350 μmol/m2 per s), five cores were semi-shaded (175 μmol/m2 per s), and five cores were shaded (70 μmol/m2 per s). Chlorophyll a increased in all treatments, but accumulated slower with increasing temperature. Surface diatom biomass of biofilms (as determined from measurements of minimum fluorescence, Fo15), grown at 10 °C and 18 °C was sustained above initial levels after 21 days, whilst biofilms grown at 26 °C suffered a severe loss of diatoms after 14 days, probably owing to nutrient limitation. Species richness and diversity of diatom assemblages illustrated a variety of responses to the temperature and light conditions. Diatoms at 10 °C acclimated to the different light levels by varying the ratios of diadinoxanthin: chlorophyll a, whilst at 18 °C the diatom species composition changed dramatically in response to shading. Ratios of zeaxanthin: chlorophyll a increased with increasing temperature, indicating an increase in cyanobacterial biomass at 26 °C after 21 days. Increased temperature significantly increased the maximum theoretical electron transport rate (rETRmax) in the short term (days), although light and temperature treatments did not affect the maximum light utilization coefficient (αrETR). Limitations of the fluorescence methodology used to study the resultant mixed community of benthic phototrophs is discussed. Diatom vertical migration in response to light, and an alteration of the main functional taxonomic group, has implications for the interpretation and value of fluorescence data.
Macromolecular composition of unsaturated Pseudomonas aeruginosa biofilms with time and carbon source
Authors: Steinberger R. E. , Holden P. A.
Published: May 2004

Bacteria in nature grow mostly as biofilms, surface-associated cells enveloped by hydrated extracellular polymeric substances (EPS) of bacterial origin. The composite of EPS and biofilm cells is measured when quantifying bacterial biomass from natural samples. However, little is known regarding the relative magnitude of the EPS and cellular fractions of biofilm biomass, particularly in unsaturated systems such as soil and food surfaces. In this study, we examined the cellular and extracellular fractions of Pseudomonas aeruginosa biofilms for DNA, protein and carbohydrate content. Biofilms were cultured in a model laboratory system that simulates the nutrient gradients and poorly mixed nature of unsaturated systems. We found that unsaturated biofilms exhibited two growth phases – an initial rapid phase and a second phase of slower or negligible development. However, no lag phase was observed for either carbon source. Cellular DNA accumulated linearly with biomass whereas cellular protein and carbohydrates accumulated exponentially with biomass. High levels of carbohydrate, protein and DNA were observed in the EPS of all samples, representing as much as 50% of these macromolecules in the biofilm. Most EPS accumulated during the second phase of growth, when cellular DNA increased only slightly. However, for biofilms cultured on a poorly bioavailable carbon source, EPS DNA decreased during the second phase, suggesting that EPS may affect bacterial survival under nutrient-limited conditions. Whether a product of overflow metabolism or cell lysis, EPS is a significant component of unsaturated biofilm biomass that probably impacts on bacterial ecology.
Combined effect of chelating agents and ultrasound on biofilm removal from stainless steel surfaces. Application to “Escherichia coli milk” and “Staphylococcus aureus milk” biofilms
Authors: Oulahal N. , Martial-Gros A. , Bonneau M. , Blum L. J.
Published: May 2004

Two ultrasonic devices – flat (T1) and curved (T2) ultrasonic transducers – were developed to remove biofilms from opened and closed surfaces, respectively. The aim is to standardize biofilm removal for in situ sanitary control in the food industry. The biofilms studied in this work were model biofilms made with milk on stainless steel sheets. We have shown in a previous study that sonication could be employed to remove and resuspend biofilm consistently, with a good recovery rate, from opened surfaces. Plate counting was used to assess the efficiency of each treatment. A total removal of Escherichia coli and Staphylococcus aureus from model biofilms was obtained with T1: 10 s at 40 kHz. However, ultrasound applied with T2 (a patented curved transducer developed for closed surfaces: 10 s at 40 kHz) failed to completely remove these model biofilms: 30±7% and 66±10% for E. coli and S. aureus biofilms, respectively. In order to improve the biofilm removal from closed surfaces with T2, the effect of the application of ultrasound in combination with chelating agent preparations was investigated. The application of ultrasound with T2 in 0.05 mol EDTA or EGTA per litre dislodged the E. coli milk model biofilm, with 100±10% and 100±5% recovery yields, respectively. These results showed a synergism between ultrasonic waves and chelator preparations, i.e. the combination achieved three times the recovery rate of sonication alone (30%). However, when the same treatment was applied to the S. aureus milk model biofilm, the combined treatment with EDTA or EGTA did not significantly improve the recovery of the biofilm cells: 74±26% with EDTA at 0.025 mol/l and 41–47% with EGTA at 0.025 mol/l and 0.05 mol/l, respectively, compared with 66±10% for sonication alone. The combined treatment was in agreement with an industrial control, i.e. a good reproducible recovery of the biofilm in a few seconds (10 s) for E. coli milk biofilms but not for S. aureus biofilms.
Introducing Biofilms
Authors: Costerton W. J. , Wilson M.
Published: May 2004

The concept that bacteria live preferentially in matrix-enclosed communities attached to surfaces has emerged gradually from scientific observations over an extended period of time, but the pace at which this concept has advanced has accelerated sharply during the past two decades. Because Antonie van Leuwenhoek examined his own teeth scrapings with his primitive microscope, he probably saw more biofilm fragments than planktonic cells, and dental microbiologists and waste-water engineers have had a lengthy association with biofilms without using that term. Early microscopic observations of marine systems showed that most bacteria adhered actively to surfaces, and the role of surfaces in the migration and maturation of myxobacterial communities was noted very early in the study of these fascinating organisms. The new concept that was crystallized in a Scientific American article in February 1978 (Costerton, J. W., Geesey, G. G. & Cheng, K. J. (1978) How bacteria stick. Scientific American238, 86–95) was that these surface associations were the rule (and not the exception) in all nutrient-sufficient microbial ecosystems, and that most bacteria in the biosphere grow in biofilms.
Stability of Source Localization with LORETA of Visual Target Processing
Authors: Herrmann Martin J. , Fallgatter Andreas J.
Published: May 2004

Abstract This study investigates whether LORETA, a method of source localization of EEG data, reveals replicable and valid sources of event-related potentials (ERPs), which are supposed to be generated in a widespread cortical network. For that purpose, the ERPs in a rare primer (= target) and a frequent distractor condition (= nontarget) of a visually presented Continuous Performance Test (CPT) were analyzed in two independent samples of healthy subjects (n1 = 49, n2 = 38). At about 420ms significantly higher global field power values (GFP) were observed in the target condition as compared to the nontarget condition. For both samples the LORETA source localization revealed significantly higher activation for the target-condition as compared to the nontarget condition in the anterior cingulum, the precuneus and superior-posterior parietal cortex (parietal lobe), the insula, and the fusiform gyrus (temporal lobe). Only in the second sample were widespread areas in the frontal cortex also activated. The results indicate that LORETA localizes widespread cortical areas involved in target processing similar to results of fMRI studies.
Response-Specific Scalp Distributions in Deception Detection and ERP Correlates of Psychopathic Personality Traits
Authors: Miller Antoinette R. , Rosenfeld J. Peter
Published: May 2004

Abstract University students were screened using items from the Psychopathic Personality Inventory and divided into high (n = 13) and low (n = 11) Psychopathic Personality Trait (PPT) groups. The P300 component of the event-related potential (ERP) was recorded as each group completed a two-block autobiographical oddball task, responding honestly during the first (Phone) block, in which oddball items were participants' home phone numbers, and then feigning amnesia in response to approximately 50% of items in the second (Birthday) block in which oddball items were participants' birthdates. Bootstrapping of peak-to-peak amplitudes correctly identified 100% of low PPT and 92% of high PPT participants as having intact recognition. Both groups demonstrated malingering-related P300 amplitude reduction. For the first time, P300 amplitude and topography differences were observed between honest and deceptive responses to Birthday items. No main between-group P300 effects resulted. Post-hoc analysis revealed between-group differences in a frontally located post-P300 component. Honest responses were associated with late frontal amplitudes larger than deceptive responses at frontal sites in the low PPT group only.
Autonomic Dysfunctions in Patients with Anxiety Throughout Therapy
Authors: Mussgay L. , Rüddel H.
Published: May 2004

Abstract Patterns of autonomic cardiovascular regulation were studied in patients with anxiety throughout the course of an intensive inpatient rehabilitation therapy at rest, and in response to an anxiety provocation, in order to measure reactivity changes. Patients had to meet the ICD-10 criteria: F40.0 (agoraphobia), F40.00 (agoraphobia without panic attacks), F40.01 (agoraphobia with panic attacks), or F41 (panic disorder). Thirty-eight patients (13 males, 25 females) were examined after recruitment (T1) and at the end of treatment (T2). Each laboratory session consisted of a resting baseline (5min) and two stress tests of 8min (presentation of word pairs with either neutral or with anxiety-related content). A continuous assessment of ECG, blood pressure, breathing pattern, and thoracic impedance allowed the calculation of heart rate variability (power spectra), baroreflex sensitivity, stroke volume, vascular compliance, and total peripheral resistance. In general, therapy had little impact on the parameters of autonomic cardiovascular regulation, neither on resting level nor on reactivity. Diminished baroreflex sensitivity values in our patients with anxiety were observed; in particular, 15% of the patients had values below 3ms/mmHg, which indicates an increased risk for cardiovascular mortality. Low baroreflex sensitivity in this group goes along with further changes within the cardiovascular system (higher heart rate, diminished heart rate variability, lower stroke volume, higher vascular compliance). This general effect describes altered sympathetic/parasympathetic balance and may be the consequence of illness-related changes in behavior. Our results suggest that a careful cardiovascular examination of patients with anxiety will detect patients with clinically significant cardiovascular alterations. This might lead to a more complex intervention in these patients including, for example, exercise training.
The role of midlatitude storms on air‐sea exchange of CO2
Authors: Perrie William , Zhang Weiqing , Ren Xuejuan , Long Zhenxia , Hare Jeff
Published: May 2004

Hurricanes influence the local rates of air‐sea CO2 exchange. Changes in fCO2w, the fugacity of CO2 in bulk water, result from storm‐induced sea surface temperature (SST) changes and from upwelling. Using numerical studies and comparing recent formulations for the gas transfer velocity kL, we discuss the impact of Hurricane Gustav (2002) on fCO2w and air‐sea CO2 exchange. We show that Gustav resulted in enhanced CO2 flux, with the maximum occurring at the storm's peak intensity.
Subvisual cirrus cloud observations using a 1064‐nm lidar, a 95 GHz cloud radar, and radiosondes in the warm pool region
Authors: Iwasaki Suginori , Tsushima Yoko , Shirooka Ryuichi , Katsumata Masaki , Yoneyama Kunio , Matsui Ichiro , Shimizu Atsushi , Sugimoto Nobuo , Kamei Akihide , Kuroiwa Hiroshi , Kumagai Hiroshi , Okamoto Hajime
Published: May 2004

We performed synergy observation of subvisual cirrus clouds (SVC) with 1064‐nm lidar, 95‐GHz cloud radar and radiosondes launched every 3 hours at 2°N, 138°E for one month from 9 November to 9 December 2001. The estimated effective radius reff of SVC is 9–16 μm (5–9 μm in mode radius). This assumes that the shape of cloud particles is spherical and the number concentration of the particles is 105 m−3. SVC disappear when temperature anomalies exceed +1.5°C. The fall velocity of SVC is same as the downward velocity of the phase propagation of the Kelvin wave, and the terminal velocity of hexagonal particles. Thus sedimentation and phase propagation are important for dissipation of SVC. In addition, it was noted that SVC tended to disappear at midday during the observational period except on 27 November 2001.
Dawn‐dusk asymmetry of geosynchronous magnetopause crossings
Authors: Dmitriev A. V. , Suvorova A. V. , Chao J. K. , Yang Y.‐H.
Published: May 2004

Geosynchronous magnetopause crossing (GMC) data were collected from literature sources from 1967 to 1993 (189 GMCs) and from the experimental data on magnetic measurements on GOES (129 GMCs) and plasma measurements on LANL (197 GMCs) geosynchronous satellites in 1994 to 2001. The dawn‐dusk asymmetry of the magnetopause at geosynchronous orbit was examined by two independent methods using the collected data set of 515 GMCs. First, the large amount of accumulated GMCs permitted the revealing of a substantial dawn‐dusk asymmetry in the local time (LT) distribution of the GMC occurrence probability, with a statistically significant maximum in the range from 1000 LT to 1100 LT. Second, an analysis of the dawn‐dusk asymmetry dependence on the upstream solar wind conditions was performed using a scatter plot of the solar wind total pressure versus local time for various IMF Bz. There was no asymmetry revealed for large positive Bz. Under strong negative Bz we found a prominent magnetopause dawn‐dusk asymmetry. The asymmetry is characterized by a shifting of the GMCs with the minimal required solar wind total pressure toward the dawn and by a significantly lower (about 3 times) solar wind pressures required for the GMCs in the dawn sector relative to the dusk sector. We found that the asymmetry cannot be attributed to the IMF orientation along the Parker spiral, which is not revealed for strongly disturbed solar wind conditions accompanying the GMCs. An application of the dawn‐dusk asymmetry effect for the Chao et al. [2002] model provided a substantial increase in the model predictive capability interim of the geosynchronous magnetopause crossings. The standard deviation decreased by 20% from 0.55 RE for the initial version to 0.45 RE for the asymmetrical version of the model, with the magnetopause axis rotated by an angle of about 15° toward the dawn. The physical processes responsible for the magnetopause dawn‐dusk asymmetry are discussed. We indicate the two most probable magnetospheric phenomena, which would contribute to the substantial dawn‐dusk asymmetry of the magnetopause under disturbed solar wind and geomagnetic conditions. The first one is that magnetopause erosion would operate more intensively in the prenoon sector. The second phenomenon is an asymmetrical terrestrial ring current that would develop during geomagnetic storms.
Multi‐scale variability of the sea surface temperature in the Tropical Atlantic
Authors: Andreoli Rita Valéria , Kayano Mary Toshie
Published: May 2004

Tropical Atlantic (TA) sea surface temperature (SST) variability is studied using the Continuous Wavelet Transform (CWT) of the SST indices in the Tropical North Atlantic (TNA), Tropical South Atlantic (TSA), and Equatorial Atlantic (EQA). CWT of the difference index (TNSD) between the TNA and TSA indices and the cross‐wavelet spectrum for the TNA and TSA indices are also examined. The analyses focus the short‐interannual, interannual, and decadal scales. The Global Wavelet Power of the TNA, TSA, and EQA indices confirm previous findings on the dominant scales of the SST variability in different TA sectors. The decadal peaks are dominant for the TNA and TSA indices while the interannual peaks are significant only for the EQA index. The scale averaged ΔΦ series for all scales feature a number of abrupt reversals of ±180° which depends on the scale, with larger number for smaller scales. The ΔΦ during the period between two subsequent abrupt reversals remains close to ±180° or varies within sub‐intervals of the −180° to +180° range, thus the dipole‐like, cross‐equatorial SST anomaly gradient, monopole, and equatorial patterns are established as evolving modes. For all scales, the periods of abrupt ΔΦ reversals of ±180° occur within the periods with change in the meridional propagation directions of the SST anomalies or with reduced SST anomalies. This result strongly suggests that the establishment of the SST anomaly patterns in the TA depends crucially on the meridional propagation of the SST anomalies. This is a new aspect not discussed before.
Neuronal nitric oxide synthase gene expression in human pituitary tumours: a possible association with somatotroph adenomas and growth hormone‐releasing hormone gene expression
Authors: Ueta Yoichi , Levy Andrew , Powell Michael P. , Lightman Stafford L. , Kinoshita Yoshimasa , Yokota Akira , Shibuya Izumi , Yamashita Hiroshi
Published: May 2004

OBJECTIVE

Nitric oxide (NO) has been implicated in the control of the secretory response to growth hormone‐releasing hormone (GHRH) and may also modify GH release in response to excitatory aminoacids. Although rat and mouse pituitary cell lines have been shown to express neuronal NO synthase (nNOS), there has until now been no information on nNOS gene expression in human pituitary adenomas. Our objective was to provide such data and correlate the presence of nNOS transcripts with GHRH transcripts.

PATIENTS

Pituitary adenoma tissue was obtained from a random selection of 32 patients with somatotrophadenomas, 16 patients with corticotroph adenomas, 39 patients with endocrinologically inactive adenomas and nine patients with macroprolactinomas undergoing transsphenoidal hypophysectomy.

MEASUREMENTS

Transcripts for nNOS and GHRH were indentified in frozen tissue sections by in situ hybridization histochemistry using synthetic 35S‐labelled oligodeoxynucleotide probes with 100% homology to the target transcript.

RESULTS

Neuronal NOS transcripts were identified in one of 16 corticotroph adenomas (6%), one of nine macroprolactinomas (11%), six of 39 endocrinologically inactive adenomas (15%) and 13 of 32 somatotroph adenomas (41%). GHRH transcripts were found in a similar distribution to nNOS transcripts in 10 of the 13 nNOS‐expressing somatotroph adenomas, and in three of the four remaining adenomas from which suitable tissue was available. Cross‐hybridization of the nNOS and GHRH probes to the same target was excluded by including rat brain sections cut through the arcuate nucleus as hybridization controls. Furthermore, two different nNOS oligodeoxynucleotide probes complementary to different regions of the target transcript produced identical results.

CONCLUSIONS

These results suggest that there is a close correlation between nNOS gene expression and ‘ectopic’ expression of GHRH in human pituitary tumours, especially somatotroph adenomas. The relevance of these findings from a functional or pathologenic viewpoint remains unclear, but the data again emphasize that it is not just GH secretion that distinguishes somatotroph adenomas from other pituitary tumours.