bluuebunny/crossref_metadata_2025 huggingface dataset:
Hexavalent chromium reduces larval growth and alters gene expression in mummichog (Fundulus heteroclitus)
Authors: Roling Jonathan A. , Bain Lisa J. , Gardea-Torresdey Jorge , Bader Julia , Baldwin William S.
Published: September 2006

Hexavalent chromium [Cr(VI)] is a common bioavailable metal ion that causes oxidative stress, DNA adducts, and perturbs gene expression. Changes in gene expression are useful biomarkers of toxicant exposure that provide information about an organism's health, adaptability, and toxicant-specific effects. Therefore, we developed a cDNA array for the estuarine sentinel species mummichog (Fundulus heteroclitus). Mummichog larvae were exposed to concentrations ranging from 0 to 24 mg/L (462 μM) of Cr(VI) for 30 d, and growth was measured to determine the no-observable-effect concentration (1.5 mg/L) and the lowestobservable- effect concentration (3 mg/L). Body burdens from Cr(VI)-exposed fish showed a dose-dependent increase and were inversely correlated to body weight. Mummichog larvae exposed to Cr(VI) differentially expressed 16 genes in a dose-dependent manner, including GLUT-2, L-FABP, ATPase synthase 8, type II keratin, TBT-binding protein, and complement component C3–2. Many of these genes are involved in energy metabolism or growth, which is consistent with the reduced growth observed. In subsequent experiments, adults were exposed to Cr(VI) for 7 d at 0, 1.5, or 3 mg/L, because adult mummichog are used in monitoring Superfund sites. Hexavalent chromium altered the expression of 10 genes in adult liver, including HGFA, H-FABP, and complement component C3–2. Many of these genes also are involved in energy metabolism. The mummichog arrays provide a potential mechanism for the effects of Cr(VI) on growth. We anticipate using these arrays and the data they provide to monitor effects at polluted sites, to assess the bioavailability of chromium at these sites, and to investigate the efficacy of remediation in chromium-polluted estuaries.
Concentrations and partitioning of polychlorinated biphenyls in the surface waters of the southern Baltic Sea—seasonal effects
Authors: Smith Kilian E.C. , McLachlan Michael S.
Published: September 2006

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

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

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

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

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

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

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

This paper discusses new techniques for the modeling and simulation of naturally fractured reservoirs with dual-porosity models. Most of the existing dual-porosity models idealize matrix-fracture interaction by assuming orthogonal fracture systems (parallelepiped matrix blocks) and pseudosteady-state flow. More importantly, a direct generalization of single-phase flow equations is used to model multiphase flow, which can lead to significant inaccuracies in multiphase flow-behavior predictions. In this work, many of these existing limitations are removed in order to arrive at a transfer function more representative of real reservoirs.

First, combining the differential form of the single-phase transfer function with analytical solutions of the pressure-diffusion equation, an analytical form for a shape factor for transient pressure diffusion is derived to corroborate its time dependence. Further, a pseudosteady shape factor for rhombic fracture systems is also derived and its effect on matrix-fracture mass transfer demonstrated. Also, a general numerical technique to calculate the shape factor for any arbitrary shape of the matrix block (i.e., non-orthogonal fractures) is proposed. This technique also accounts for both transient and pseudosteady-state pressure behavior. The results were verified against fine-grid single-porosity models and were found to be in excellent agreement.

Second, it is shown that the current form of the transfer function used in reservoir simulators does not fully account for the main mechanisms governing multiphase flow. A complete definition of the differential form of the transfer function for two-phase flow is derived and combined with the governing equations for pressure and saturation diffusion to arrive at a modified form of the transfer function for two-phase flow. The new transfer function accurately takes into account pressure diffusion (fluid expansion) and saturation diffusion (imbibition), which are the two main mechanisms driving multiphase matrix-fracture mass transfer. New shape factors for saturation diffusion are defined. It is shown that the prediction of wetting-phase imbibition using the current form of the transfer function can be quite inaccurate, which might have significant consequences from the perspective of reservoir management. Fine-grid single-porosity models are used to verify the validity of the new transfer function. The results from single-block dual-porosity models and the corresponding single-porosity fine-grid models were in good agreement.
Improving Patient Adherence
Authors: Delamater Alan M.
Published: September 2006

IN BRIEF

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

In Brief

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

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

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

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

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

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

Das Interesse an Metallkomplexen, die molekularen Stickstoff binden und seine Reduktion oder Oxidation unter milden Bedingungen bewirken, ist weiterhin ungebrochen. In der Natur katalysiert das Enzym Nitrogenase diesen Prozess. Unter milden Zellbedingungen findet die Distickstoff‐Fixierung an einem Metall‐Schwefel‐Cluster im Zentrum des MoFe‐Proteins statt. Details des Mechanismus sind jedoch weithin unbekannt, obwohl gerade in den letzten Jahren wichtige Entdeckungen in diesem Gebiet gemacht wurden. Im vorliegenden Aufsatz werden neueste Resultate über Wechselwirkungen von N2 mit Metallatomen und Metallatom‐Dimeren aller Gruppen des Periodensystems diskutiert, die vor allem in Gasphasen‐ und Matrixisolationsexperimenten gewonnen wurden. Die Relevanz dieser intrinsischen Distickstoff‐Aktivierung an ligandenfreien Metallatomen für die entsprechenden Reaktionen an Komplexen, Clustern und Oberflächen wird hervorgehoben.
p53 – ein natürlicher Krebskiller: Einsichten in die Struktur und Therapiekonzepte
Authors: Römer Lin , Klein Christian , Dehner Alexander , Kessler Horst , Buchner Johannes
Published: September 2006

Jeden Tag mutiert die DNA einer jeden Zelle im menschlichen Körper – sogar in Abwesenheit von Onkogenen oder extremer Strahlung – tausende Male. Viele dieser Mutationen würden zu Krebs und schließlich zum Tod führen. Um dem entgegenzuwirken, haben vielzellige Organismen ein effizientes Kontrollsystem mit dem Tumorsuppressorprotein p53 als dem zentralen Element entwickelt. Ein intaktes p53‐Netzwerk gewährleistet, dass DNA‐Schäden frühzeitig entdeckt und repariert werden. Die Bedeutung von p53 für die Prävention von Krebs wird dadurch deutlich, dass p53 in mehr als 50 % aller menschlichen Tumoren inaktiviert vorliegt. Aus diesem Grund ist p53 eines der am intensivsten untersuchten Proteine. Trotz der großen Anstrengungen, die unternommen wurden, um dieses Protein zu charakterisieren, sind seine Struktureigenschaften und komplexen Funktionen bisher nur teilweise aufgeklärt. Dieser Aufsatz behandelt vorrangig grundlegende Konzepte und jüngste Fortschritte für das Verständnis der Struktur und Regulierung von p53, unter besonderer Berücksichtigung neuer Therapieansätze.
Synthesis, spectral and biological studies of organotin(IV) complexes of heteroscorpionate
Authors: Joshi Rajkumar , Sharma Guruaribam Shashikumar , Kumar Vikrant , Adil Hashmi Athar , Kumar Satyendra , Achila R. , Ejaz Hussain M.
Published: September 2006

A heteroscorpionate ligand, potassium hydrobis(benzoato)(salicylaldehyde)borate (KL), has been synthesized. This was converted into organotin complexes R2SnL2 and R3SnL complexes by mixing and stirring with a methanolic solution/suspension of organotin chloride. The ligand and its complexes were characterized by elemental analyses and spectral studies (IR, 1H NMR, 13C NMR, ESI mass spectra and Thermo gravimetric analysis (TGA)). Antibacterial and antifungal studies of these compounds were evaluated by the disc diffusion method at variable concentration against three species of bacteria (Staphylococcus aureus, Klebsiella pneumonia and Bacillius subtillis) and two species of fungi (Asperjillius fiavus and Candida albicans). It was found that triorganotin derivatives (R3SnL) of the ligand were more effective as compared with diorganotin derivatives (R2SnL2). The organotin complexes of borates were tested for their algicidal activity on the cyanobacterial strains Aulosira fertilissma, Anabaena species, Anabaena variabilis and Nostoc muscorum and showed high to moderate toxicity towards the above species. The ligand and its complexes were also tested for its pH effect on soil in vitro for a duration of more than one month and it was found that they are able to kill pests without damaging the soil quality. Copyright © 2006 John Wiley & Sons, Ltd.
Research Project: Charleston Bioengineered Kidney Project
Authors: Mironov Vladimir , Drake Christopher , Wen Xuejun
Published: September 2006

The goal of Charleston Bioengineered Kidney Project is to engineer a functional living human kidney suitable for surgical implantation using principles of directed tissue self‐assembly and tissue fusion. This is a multidisciplinary project which incorporates multiple innovative bioengineering technologies and expertise from a broad spectrum of disciplines. The conceptual framework, engineering principles, design, potential cell source as well as the first preliminary data demonstrating the feasibility of the proposed Charleston Bioengineered Kidney Project are outlined. The potential challenges are described. Finally, the experts' opinion about the proposed project is also presented.
Imaging technology of the future
Authors: Persson A
Published: September 2006

Expectation of imaging-based treatments
Letter 1: Systematic review of outcome of synchronous portal-superior mesenteric vein resection during pancreatectomy for cancer (Br J Surg 2006; 93: 662–673)
Authors: Buckels J A C , Bramhall S R
Published: September 2006

The Editors welcome topical correspondence from readers relating to articles published in the Journal. Responses should be sent electronically via the BJS website (www.bjs.co.uk). All letters will be reviewed and, if approved, appear on the website. A selection of these will be edited and published in the Journal. Letters must be no more than 250 words in length.
Prognostic stratification of patients with anaplastic gliomas according to genetic profile
Authors: Dehais Caroline , Laigle‐Donadey Florence , Marie Yannick , Kujas Michele , Lejeune Julie , Benouaich‐Amiel Alexandra , Pedretti Marta , Polivka Marc , Xuan Khe‐Hoang , Thillet Joelle , Delattre Jean‐Yves , Sanson Marc
Published: September 2006

BACKGROUND.

There is a need to improve the current, controversial, and poorly reproducible classification of anaplastic gliomas, which represent a highly heterogeneous entity in terms of survival.

METHODS.

The impact of the most common genetic alterations on survival was investigated based on 156 anaplastic gliomas: Among the patients who were included, the gender ratio was 1.32, the median age was 45.5 years (range, 20–83 years), and the median Karnofsky performance status was 70 (range, 40–100). Genetic analysis included a search for loss of heterozygosity (LOH) on chromosomes 1p and 19q; amplification of chromosomes 9p and 10q and of the epidermal growth factor receptor (EGFR), cyclin‐dependent kinase 4 (CDK4) and mouse double‐minute (MDM2) genes; and p53 expression.

RESULTS.

The median survival was 33.5 months, and the median progression‐free survival was 15.8 months. In a univariate analysis, LOH on 1p and 19q was correlated with longer survival, whereas p53 expression, LOH on 9p, LOH on 10q, amplified EGFR, and deleted CDKN2A were correlated with shorter survival. LOH on 1p and 19q were associated with oligodendrogliomas, LOH on 10q was related to EGFR amplification, and LOH on 1p and 19q was mutually exclusive with EGFR amplification and LOH on 10q. In a multivariate analysis, the significant prognostic factors were age, histology, LOH on 1p and 19q, and P16/CDKN2A deletion. Recursive partitioning analysis (RPA) divided the whole group hierarchically into 3 distinct prognostic subgroups: Group A with 1p19q codeletion (median survival, 98 months), Group B with EGFR amplification (median survival, 17 months), and Group CC (median survival, 31 months), providing a basis for a genetically based prognostic subclassification for patients with Grade III gliomas.

CONCLUSIONS.

The search for 1p19q codeletion and EGFR receptor amplification provides a simple, clinically relevant prognostic subclassification of grade III gliomas. Cancer 2006. © 2006 American Cancer Society.
Influence of initial geometric imperfections on the stability of thick cylindrical shells under internal pressure
Authors: Lopes S. R. X. , Gonçalves P. B. , Pamplona D. C.
Published: September 2006

This paper investigates numerically and experimentally the influence of initial geometric imperfections on the critical loads of initially stretched thick hyperelastic cylindrical shells under increasing uniform internal pressure. Imperfections in shells can have a global or local character. First, two types of local imperfections are considered: (1) a local axially symmetric imperfection in the form of a ring and (2) a small rectangular imperfection. The influence of the imperfection thickness, position and size are analysed in detail. Results show that the critical load decreases as the imperfections increase in size or thickness and as they move from the boundaries to the centre of the shell. The influence of multiple local imperfections is also studied in the present paper. Finally, the influence of global imperfections is considered with the imperfections described as a variation of the shell curvature in the axial direction. The results show that thick hyperelastic shells may be sensitive to local and global imperfections. In all cases the experimental results are in good agreement with the numerical ones, corroborating the conclusions. Copyright © 2006 John Wiley & Sons, Ltd.
A relation between the logarithmic capacity and the condition number of the BEM‐matrices
Authors: Dijkstra W. , Mattheij R. M. M.
Published: September 2006

We establish a relation between the logarithmic capacity of a two‐dimensional domain and the solvability of the boundary integral equation for the Laplace problem on that domain. It is proved that when the logarithmic capacity is equal to one the boundary integral equation does not have a unique solution. A similar result is derived for the linear algebraic systems that appear in the boundary element method. As these systems are based on the boundary integral equation, no unique solution exists when the logarithmic capacity is equal to one. Hence, the system matrix is ill‐conditioned. We give several examples to illustrate this and investigate the analogies between the Laplace problem with Dirichlet and mixed boundary conditions. Copyright © 2006 John Wiley & Sons, Ltd.
Three‐dimensional elastoplastic analysis by triple‐reciprocity boundary element method
Authors: Ochiai Yoshihiro
Published: September 2006

In general, internal cells are required to solve elastoplastic problems using a conventional boundary element method (BEM). However, in this case, the merit of BEM, which is ease of data preparation, is lost. Triple‐reciprocity BEM can be used to solve two‐dimensional elastoplasticity problems with a small plastic deformation. In this study, it is shown that three‐dimensional elastoplastic problems can be solved, without the use of internal cells, by the triple‐reciprocity BEM. An initial strain formulation is adopted and the initial strain distribution is interpolated using boundary integral equations. A new computer program was developed and applied to solving several problems. Copyright © 2006 John Wiley & Sons, Ltd.
Computationally‐Assisted Approach to the Vibrational Spectra of Molecular Crystals: Study of Hydrogen‐Bonding and Pseudo‐Polymorphism
Authors: Nolasco Mariela M. , Amado Ana M. , Ribeiro‐Claro Paulo J. A.
Published: September 2006

A new computationally‐assisted methodology (PiMM), which accounts for the effects of intermolecular interactions in the crystal, is applied to the complete assignment of the Raman and infrared vibrational spectra of room temperature forms of crystalline caffeine, theobromine, and theophylline. The vibrational shifts due to crystal packing interactions are evaluated from ab initio calculations for a set of suitable molecular pairs, using the B3LYP/6‐31G* approach.The proposed methodology provides an answer to the current demand for a reliable assignment of the vibrational spectra of these methyl‐xanthines, and clarifies several misleading assignments. The most relevant intermolecular interactions in each system and their effect on the vibrational spectra are considered and discussed. Based on these results, significant insights are obtained for the structure of caffeine in the anhydrous form (stable at room temperature), for which no X‐ray structure has been reported. A possible structure based on C(8)H⋅⋅⋅N(9) and C(1,3)H⋅⋅⋅O intermolecular interactions is suggested.
Cytotoxicity of doxorubicin‐loaded Con A‐liposomes
Authors: Santos Hercília Maria Lins Rolim , de Queiroz Fernando Brederodes , Maior Rosa Maria Souto , do Nascimento Silene Carneiro , Magalhães Nereide Stela Santos
Published: September 2006

The present study investigated the potential of Concanavalin A lectin (Con A) conjugated to liposomes (Con A‐liposomes) for targeting doxorubicin (DOX) to cells. The physicochemical properties and the cytotoxicity of DOX‐loaded Con A‐liposomes were evaluated. DOX‐loaded Con A‐liposomes were prepared by incubation of DOX‐loaded liposomes with a Con A‐SATA derivative. Lectin biological activity was monitored before and after conjugation by a hemagglutinating assay. The cytotoxicity of DOX‐loaded Con A‐liposomes was evaluated in terms of the inhibition of NCI‐H299 and HEp‐2 cell proliferation using the MTT method. The affinity of lectinized liposomes with these cells was thus assessed by evaluating the cytotoxic effect of the DOX released into cells. Stable DOX‐loaded Con A‐liposomes were obtained and their high affinity for cells was corroborated. The encapsulation of DOX into Con A‐liposomes produced an inhibition of roughly 70% of Hep‐2 cell proliferation and 50% of cell inhibition was verified on HCI‐H292. DOX in solution was able to inhibit only 20% of cell proliferation for both cell lines. Unloaded Con A‐liposomes were not cytotoxic. The encapsulation of DOX into Con A‐liposomes improves drug penetration into cells, thereby enhancing its cytotoxicity, especially in Hep‐2 cells. Drug Dev. Res. 67:430–437, 2006. © 2006 Wiley‐Liss, Inc.
The novel depot of buprenorphine propionate has a long‐acting effect on physical dependence on morphine
Authors: Liu Kuo‐Sheng , Lin Ching‐Nan , Shieh Ja‐Ping , Chu Chin‐Chen , Kuei Chun‐Hsiung , Wang Jhi‐Joung
Published: September 2006

Buprenorphine is a promising drug for the treatment of physical dependence on opioids. The aim of the present study was to evaluate the efficacy and duration of action of a novel depot form of a buprenorphine prodrug, buprenorphine propionate, on physical dependence on morphine. Following intramuscular injection in morphine‐dependent mice, the efficacy and duration of action of buprenorphine propionate in sesame oil were evaluated. Two other dosage forms of buprenorphine were used as controls. Intramuscular injection of buprenorphine HCl (0.1 µmol/kg in saline) attenuated the severity of morphine dependence (P<0.05) with a 9‐h duration of action. However, a further increase in dose up to 60‐fold could not further increase its duration of action. On the other hand, buprenorphine base and propionate when prepared in sesame oil produced longer durations of action than did buprenorphine HCl in saline under an equimolar basis of 6 µmol/kg (P<0.05, for each comparison). Among dosage forms, buprenorphine propionate in sesame oil produced the longest duration of action, 11.3‐fold longer than that of buprenorphine HCl in saline and 2‐fold longer than buprenorphine base in oil. In conclusion, the novel depot of buprenorphine propionate produced a dose‐related long‐acting effect on physical dependence on morphine in mice. Drug Dev. Res. 67:462–469, 2006. © 2006 Wiley‐Liss, Inc.
In silico prediction of cytochrome P450 inhibitors
Authors: Refsgaard Hanne H. F. , Jensen Berith F. , Christensen Inge Thøger , Hagen Nina , Brockhoff Per B.
Published: September 2006

Patients often receive several medications at the same time, and if the drugs involved compete for the same enzymes to be metabolized, it can lead to undesired effects with the risk of fatal results. Therefore, early knowledge about the cytochrome P450 (CYP) interaction potential of a drug candidate is central and in silico tools can provide such information even on virtual structures. Most of the in silico CYP information in the literature is on substrates and is based on molecular and protein modeling. However, in early screening information of CYP substrates is rarely available and sometimes only a single concentration is used in screening assays. Recently, in silico CYP modeling applying statistical tools has appeared in the literature and the aim of this review is to give an overview of published in silico prediction studies of CYP inhibition for four of the clinically most important isotypes, namely: CYP1A2, CYP2C9, CYP2D6, and CYP3A4. Furthermore, in the review, we discuss inhibition data, different descriptors and statistical methods applied for in silico prediction of CYP inhibition, and we point to promising approaches in the development of accurate in silico prediction tools of CYP inhibitors. Drug Dev. Res. 67:417–429, 2006. © 2006 Wiley‐Liss, Inc.
Element‐localized Doppler STAP (Space Time Adaptive Processing) for clutter suppression in automotive forward‐looking RADAR
Authors: Inaba Takayuki
Published: September 2006

In forward‐looking radars such as automotive radars, it is necessary to suppress the reflected undesirable signal (clutter) from such objects as the ground surface (especially hills), guard rails, and buildings, in order to detect moving targets ahead. When using a pulse‐Doppler filter (PDF), which is the conventional method for clutter suppression, separation is difficult when the velocity of the target relative to the clutter is small. In this paper, as a high performance clutter suppression method for such low‐velocity targets, we propose element‐localized Doppler space time adaptive processing (ELD‐STAP), which includes a PDF in the preprocessing, and which uses an array antenna. In the proposed ELD‐STAP, only the PDF output corresponding to the Doppler frequency breadth of the clutter, predicted from the speed of the vehicle on which it is mounted, is selected for applying STAP, and hence the dimension of the data vector, which is the greatest difficulty in the application of STAP, can be reduced. By reducing the dimension of the data vector, not only the computation load, but also the number of cells that must be referenced to estimate the clutter correlation matrix (called secondary cells), can be reduced. Computer simulation reveals that the proposed ELD‐STAP yields an improvement factor better than that provided by the combination of PDF and multibeam forming (MBF). © 2006 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(1): 77–89, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20221
Influence of TCP congestion control on multifractal nature of network traffic
Authors: Doi Hiroki , Matsuda Takahiro , Yamamoto Miki
Published: September 2006

The multifractal nature of traffic volume is known to have significant influence to queuing behavior in network nodes. In the Internet, TCP traffic, which is the major traffic flowing through the Internet has been reported to have multifractal nature. To control the effect of the multifractal nature, the origin of the multifractal nature in TCP traffic needs to be explained. However, it is still unclear what part of TCP control mostly affects the multifractal nature. In this paper, we focus on TCP congestion control from the viewpoint of multifractal nature of generated traffic. We investigate “what component of TCP congestion control mechanism affects multifractal nature of generated traffic?” Our simulation results show that Retransmission Time‐Out mechanism plays an important role for multifractal nature of TCP traffic. In addition, our results show that avoiding occurrence of Retransmission Time Out is the best approach to improve TCP performance, i.e., throughput degradation, LRD, and multifractal nature. Random Early Detection (RED), based on the fact that Retransmission Time Out should be avoided, to improve TCP performance are also reasonable from the viewpoint of LRD and multifractal nature. © 2006 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(1): 68–76, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20277
Congestion control with multiple congestion control policy for large bandwidth‐delay‐product networks
Authors: Saito Kentaro , Igarashi Ken , Ihara Takeshi , Miura Akira
Published: September 2006

Recently, broadband applications such as data grids and IP‐Storage Area Network have been proliferating. In these applications it is necessary to exchange large amounts of data quickly over networks with a capacity of several gigabits per second. For this purpose, various kinds of congestion control have been proposed for use in such broadband networks. In these kinds of congestion control, the idle bandwidth of the network can be used quickly by increasing the communications speed at the time of communications. On the other hand, complicated forms of congestion are generated in the network. Therefore, when these kinds of congestion control and the existing TCP communications coexist, the existing TCP communication is strongly compressed. In the present paper, TCP with multiple congestion control policies (TCP‐MP) is proposed in order to make swift use of idle bandwidths in the network. In TCP‐MP, an additional congestion control policy is provided in addition to using a form of congestion control similar to that in conventional TCP, so that information on the variation of the RTT between the transmitter and the receiver can be used to estimate the idle bandwidth of the network and the communications speed is chosen in such a way that the idle bandwidth is used up. Hence, it is possible to quickly use the bandwidth of the network within the range in which the existing TCP communications is compressed. © 2006 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(1): 45–57, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20310
Estimation of lightning location from single station observations of sferics
Authors: Nagano Isamu , Yagitani Satoshi , Ozaki Mitsunori , Nakamura Yoichi , Miyamura Kazutoshi
Published: September 2006

A system for lightning location from single station observations has been developed for localizing lightning (distance and direction) at rather short distances (several hundred kilometers). In this system, a vertical component of the electric field and two horizontal components of the magnetic field of the VLF wave of the sferics are observed. The sferics are usually observed as a pulse train. The first pulse is used for estimation of the direction. The second and subsequent pulses are multiple reflections between the ionosphere and the ground. The differences in arrival time of these reflected waves are determined by the propagation distance between the ground and the ionosphere. The reflection altitude of the ionosphere and the horizontal distance to the lightning location are estimated from the arrival time difference of more than two pulses. In this research, the electromagnetic pulses radiated from the lightning are first analyzed by the full wave method, considering the ionosphere, free space, and the ground, in order to evaluate the location estimation method. The lightning location is estimated by calculating the space discharge sferics waveform at the observation point. Observations were also carried out with the lightning location system for estimation of lightning locations. © 2006 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(1): 25– 34, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20329