bluuebunny/crossref_metadata_2025 huggingface dataset:
Oxygen‐Enhanced Biodegradation of Phenoxy Acids in Ground Water at Contaminated Sites
Authors: Tuxen Nina , Reitzel Lotte A. , Albrechtsen Hans‐Jørgen , Bjerg Poul L.
Published: August 2005

The effects of adding oxygen to anaerobic aquifer materials on biodegradation of phenoxy acid herbicides were studied by laboratory experiments with aquifer material from two contaminated sites (a former agricultural machinery service and an old landfill). At both sites, the primary pollutants were phenoxy acids and related chlorophenols. It was found that addition of oxygen enhanced degradation of the six original phenoxy acids and six original chlorophenols. Inverse modeling on 14C 4‐chloro‐2‐methylphenoxypropanoic acid (MCPP) degradation curves revealed that increasing the oxygen concentrations from <0.3 mg/L up to 7 to 8 mg/L shortened the lag phases (from ∼150 d to 5 to 25 d) and increased first‐order degradation rate constants by 1 order of magnitude (from ∼5 × 10−2 d−1 to up to 30 × 10−2 d−1). Additionally, the degree of MCPP mineralization was increased (30% to 50% mineralized at low oxygen concentrations and 50% to 70% mineralized at high oxygen concentrations, based on 14CO2 recovery). These positive effects on degradation were observed even at relatively low oxygen concentrations (2 mg/L). Furthermore, effects related to the addition of oxygen on the general geochemistry were studied. An oxygen consumption of 2.2 to 2.6 mg O2/g dw was observed due to oxidation of solid organic matter and, to some extent (0.5% to 11% of the total oxygen consumption), water‐soluble compounds such as Fe2+, dissolved Mn, nonvolatile organic carbon, and NH4+. Overall, the results suggest that stimulated biodegradation by addition of oxygen might be a feasible remediation technology at herbicide‐contaminated sites, although oxygen consumption by the sediment could limit the applicability.
Steady‐State Soil Vapor Extraction from a Pressure‐Controlled or Flow‐Controlled Well
Authors: Perina Tomas , Lee Tien‐Chang
Published: August 2005

An analytical solution for steady‐state soil vapor extraction (SVE) is derived for both pressure‐controlled and flow‐controlled well with nonuniform radial flux along the well screen. Since the flow rate and wellhead pressure are not lumped into a single variable, the solutions developed here can predict wellhead pressures required to achieve desired extraction rates. Simulations based on the established P (pressure) or P2 linearization of the governing air flow equation yield practically indistinguishable results for steady SVE. Existing numerical models for ground water flow can therefore be used to represent SVE in the P linearization for more complex vadose zone geometry and heterogeneous soils. The maximum differences between pressure distributions predicted by the nonuniform and uniform flux models occur near the ends of the extraction well screen and diminish with radial distance. Application to field test data indicates that estimates of horizontal and vertical soil‐air permeability by the nonuniform flux model become similar to those obtained with the uniform flux model as the extraction well screen is shortened.
Yellow wing‐patch of a nestling Horsfield's hawk cuckoo Cuculus fugax induces miscognition by hosts: mimicking a gape?
Authors: Tanaka Keita D. , Morimoto Gen , Ueda Keisuke
Published: August 2005

A chick of the Horsfield's hawk cuckooCuculus fugaxhas a vivid yellow skin patch on each wing‐bend, which is very similar in colour to its own gape. Almost every time a host parent delivers food, the chick explicitly displays the wing‐patch by raising and shaking the wing. We observed that host parents tried to place food onto the wing‐patch of the nestling instead of into its mouth. The wing‐patch would be perceived as a gape by host parents, possibly resulting in an overestimation of brood size. Signals induced by the wing‐patch may vary with the luminosity of environments.
Effect of Cl− channel blockers on aconitine‐induced arrhythmias in rat heart
Authors: Zhou Shi‐Sheng , Yang Jun , Li Yao‐Qin , Zhao Lin‐Yan , Xu Ming , Ding Yan‐Feng
Published: August 2005

The effects of Cl− channel blockers 5‐nitro‐2‐(3‐phenylpropylamino)benzoic acid (NPPB) and niflumic acid (NFA) on aconitine‐induced arrhythmias were investigated. Left ventricular pressure and electrocardiogram were monitored in Langendorff‐perfused rat hearts. Whole‐cell patch‐clamp and current‐clamp techniques were used to measure sodium current (INa) and action potential (AP), respectively, in single rat cardiac ventricular myocytes. Addition of the Na+ channel agonist aconitine (0.1 μm) to the perfusion solution produced polymorphic ventricular arrhythmias with a latent period of 25.5 ± 6.3 s. NPPB could reverse aconitine‐induced arrhythmias. A similar effect was observed by using NFA. NPPB and NFA reversibly depressed the upstroke of the AP in a dose‐dependent manner with IC50 values of ∼12.3 and ∼73.1 μm, respectively, without significantly affecting the resting potential of rat ventricular myocytes. Both Cl− channel blockers inhibited INa and induced a leftward shift of the steady‐state inactivation of INa. In conclusion, the results of this study demonstrate that NPPB as well as NFA can suppress aconitine‐induced arrhythmias in rat hearts mainly by inhibiting cardiac INa.
Molecular analysis of a consortium of ruminal microbes that detoxify pyrrolizidine alkaloids
Authors: Lodge-Ivey S L , Rappe M S , Johnston W H , Bohlken R E , Craig A M
Published: August 2005

Members of a consortium of bacteria, isolated from the rumen of sheep, that degrades pyrrolizidine alkaloids (PAs) found in tansy ragwort (Senecio jacobaea) were characterized. An enrichment of ruminal bacteria was isolated from a sample of ruminal fluid using standard anaerobic techniques. The PA degradative capacity of the enrichment was tested by spiking purified PA extract from tansy ragwort. Length heterogeneity analysis by PCR (LH-PCR) and restriction fragment length polymorphism (RFLP) analysis was used to identify members of the consortium. Phylogenetic analysis of the 16S rDNA gene revealed differing results based on the molecular method used. LH-PCR identified 7 different organisms in 3 groups while RFLP identified 6 organisms with differing banding patterns in 5 groups. After the phylogenetic analyses of both methods were combined, the combined isolates represented 6 groups. The majority of the members of this consortium are <97.0% homologous with known bacteria, indicating this consortium may contain novel organisms able to detoxify PAs found in tansy ragwort. Further understanding of the metabolic pathways used by this consortium to degrade PAs could lead to the use of the consortium as a probiotic therapy for livestock and horses afflicted with tansy ragwort toxicosis.Key words: pyrrolizidine alkaloids, ruminal bacteria, tansy ragwort, RFLP, LH-PCR.
CAN w < -1 BE EXORCIZED?
Authors: GONZÁLEZ-DÍAZ PEDRO F.
Published: August 2005

Dimming mechanisms based on the conversion of photons into axions have been recently suggested which could justify the observation of equation of state values w = P/ρ less than -1 that do not correspond to the presence of phantom energy in the universe. It is argued that, though such a mechanism may in fact increase the actual value of w, it does not actually solve the phantom problem because the produced axions precisely are of the kind which has been considered to make up phantom energy and therefore the suggested mechanism can never make the actual value of w to exactly reach the value -1 from below, such as it also happens with other suggested mechanisms intended to get rid of phantoms from cosmology. It is conjectured that the actual current value of w must likely be less than -1 but so close to it that present observational accuracies could not allow discriminating between a cosmological constant and the phantom energy as the form currently taken by dark energy in the universe.
Area MT Neurons Respond to Visual Motion Distant From Their Receptive Fields
Authors: Zaksas Daniel , Pasternak Tatiana
Published: August 2005

Neurons in cortical area MT have localized receptive fields (RF) representing the contralateral hemifield and play an important role in processing visual motion. We recorded the activity of these neurons during a behavioral task in which two monkeys were required to discriminate and remember visual motion presented in the ipsilateral hemifield. During the task, the monkeys viewed two stimuli, sample and test, separated by a brief delay and reported whether they contained motion in the same or in opposite directions. Fifty to 70% of MT neurons were activated by the motion stimuli presented in the ipsilateral hemifield at locations far removed from their classical receptive fields. These responses were in the form of excitation or suppression and were delayed relative to conventional MT responses. Both excitatory and suppressive responses were direction selective, but the nature and the time course of their directionality differed from the conventional excitatory responses recorded with stimuli in the RF. Direction selectivity of the excitatory remote response was transient and early, whereas the suppressive response developed later and persisted after stimulus offset. The presence or absence of these unusual responses on error trials, as well as their magnitude, was affected by the behavioral significance of stimuli used in the task. We hypothesize that these responses represent top-down signals from brain region(s) accessing information about stimuli in the entire visual field and about the behavioral state of the animal. The recruitment of neurons in the opposite hemisphere during processing of behaviorally relevant visual signals reveals a mechanism by which sensory processing can be affected by cognitive task demands.
Dendritic Na+ Current Inactivation Can Increase Cell Excitability By Delaying a Somatic Depolarizing Afterpotential
Authors: Fernandez Fernando R. , Mehaffey W. Hamish , Turner Ray W.
Published: August 2005

Many central neurons support active dendritic spike backpropagation mediated by voltage-gated currents. Active spikes in dendrites have been shown capable of providing feedback to the soma to influence somatic excitability and firing dynamics through a depolarizing afterpotential (DAP). In pyramidal cells of the electrosensory lobe of weakly electric fish, Na+ spikes in dendrites undergo a frequency-dependent broadening that enhances the DAP to increase somatic firing frequency. We use a combination of dynamical analysis and electrophysiological recordings to demonstrate that spike broadening in dendrites is primarily caused by a cumulative inactivation of dendritic Na+ current. We further show that a reduction in dendritic Na+ current increases excitability by decreasing the interspike interval and promoting burst firing. This process arises when inactivation of dendritic Na+ current shifts the latency of the dendritic spike to delay the arrival of the DAP sufficiently to increase its impact on somatic membrane potential despite a reduction in dendritic excitability. Furthermore, the relationship between dendritic Na+ current density and somatic excitability is nonmonotonic, as intermediate levels of dendritic Na+ current exert the greatest excitatory influence. These results reveal that temporal shifts in dendritic spike firing provide a novel means for backpropagating spikes to influence the final output of a cell.
Microarray analysis reveals novel gene expression changes associated with erectile dysfunction in diabetic rats
Authors: Sullivan Chris J. , Teal Thomas H. , Luttrell Ian P. , Tran Khoa B. , Peters Mette A. , Wessells Hunter
Published: August 2005

To investigate the full range of molecular changes associated with erectile dysfunction (ED) in Type 1 diabetes, we examined alterations in penile gene expression in streptozotocin-induced diabetic rats and littermate controls. With the use of Affymetrix GeneChip arrays and statistical filtering, 529 genes/transcripts were considered to be differentially expressed in the diabetic rat cavernosum compared with control. Gene Ontology (GO) classification indicated that there was a decrease in numerous extracellular matrix genes (e.g., collagen and elastin related) and an increase in oxidative stress-associated genes in the diabetic rat cavernosum. In addition, PubMatrix literature mining identified differentially expressed genes previously shown to mediate vascular dysfunction [e.g., ceruloplasmin ( Cp), lipoprotein lipase, and Cd36] as well as genes involved in the modulation of the smooth muscle phenotype (e.g., Kruppel-like factor 5 and chemokine C-X3-C motif ligand 1). Real-time PCR was used to confirm changes in expression for 23 relevant genes. Further validation of Cp expression in the diabetic rat cavernosum demonstrated increased mRNA levels of the secreted and anchored splice variants of Cp. CP protein levels showed a 1.9-fold increase in tissues from diabetic rats versus controls. Immunohistochemistry demonstrated localization of CP protein in cavernosal sinusoids of control and diabetic animals, including endothelial and smooth muscle layers. Overall, this study broadens the scope of candidate genes and pathways that may be relevant to the pathophysiology of diabetes-induced ED as well as highlights the potential complexity of this disorder.
Persistent Diarrhea in Developing Countries
Authors: Bhutta Zulfiqar A.
Published: August 2005

Globally diarrheal diseases account for almost a fifth of all deaths of children under 5 years, with an estimated 2.2 million deaths annually. Of these deaths, a significant proportion are related to episodes of persistent diarrhea (PD; defined as diarrhea of >14 days with growth faltering). PD has been shown to identify children with a substantially increased diarrheal burden. These account for 36–54% of all diarrhea-related deaths. Although the exact pathogenesis of PD remains unclear, most episodes are related to prior acute infectious diarrhea with prolongation of the most recent episode. This may be related to several host factors such as preexisting undernutrition, micronutrient deficiency, immune deficiency and inappropriate therapy of the most recent acute diarrheal episode. The common final event appears to be prolonged intestinal mucosal injury and ineffective repair. In contrast to post-infectious PD, some infants may have severe intractable diarrhea due to a variety of disorders, many of which have a hereditary basis. These now form the dominant type of prolonged diarrhea in developed countries. The management of PD depends upon close attention to nutritional rehabilitation and early recognition of complications. Although a variety of pathogens have been associated with PD, there is little role for oral antimicrobial therapy in the routine treatment of PD. However, attention to rehydration, appropriate screening and treatment of systemic infections and enteral nutrition rehabilitation with easily digestible diets are critical in managing such children, frequently in ambulatory settings. Administration of zinc and vitamin A may shorten the duration of PD and also help reduce recurrences. However, the most important preventive strategies for PD are exclusive breastfeeding in the first 6 months of life, continued breast feeding for 2 years with appropriate complementary feeding and optimal management of acute diarrheal episodes.
Primitive Neuroectodermal Tumor of the Kidney with Hyaline Cells
Authors: Ruszat R. , Casella R. , Bachmann A. , Gasser T.C. , Sulser T.
Published: August 2005

Primitive neuroectodermal tumor (PNET) of the kidney is a rare disease with high malignant potential. It affects young adults and has the tendency towards early metastasis. Relying on recently available immunohistochemistry and cytogenetic investigations, today most authors define PNET as part of the same nosologic entity as Ewing’s sarcoma. We present the case of a 22-year-old man with a PNET arising from the kidney with, to our knowledge, a previously undescribed finding of hyaline cells within the tumor.
Evaluation of Nyholt’s Procedure for Multiple Testing Correction
Authors: Salyakina Daria , Seaman Shaun R. , Browning Brian L. , Dudbridge Frank , Müller-Myhsok Bertram
Published: August 2005

Objective: A simple method for accounting efficiently for multiple testing of many SNPs in an association study was recently proposed by Nyholt, but its performance was not extensively evaluated. The method involves estimating an ‘effective number’ of independent tests and then adjusting the smallest observed p value using Šidák’s formula based on this number of tests. We sought to carry out an empirical and theoretical evaluation of Nyholt’s method. Methods: Nyholt’s method was applied to a sample of 31 genes typed at a total of 291 SNPs and permutation used to determine the type-I error rate for each gene. Based on our empirical results, we algebraically investigated the effective number of independent tests for a simple model of haplotype block structure. Results: The nominal 5% type I error rate varied from under 3% to over 7%, and was dependent on linkage disequilibrium. Theoretical considerations show further that the method can be very conservative in the presence of haplotype block structure. Conclusion: Although Nyholt’s approach may be useful as an exploratory tool, it is not an adequate substitute for permutation tests.
Apolipoprotein E Polymorphism and Stroke Subtypes in an Italian Cohort
Authors: Cerrato P. , Baima C. , Grasso M. , Lentini A. , Bosco G. , Cassader M. , Gambino R. , Cavallo Perin P. , Pagano G. , Fornengo P. , Imperiale D. , Bergamasco B. , Bruno G.
Published: August 2005

Background: Studies have indicated that apolipoprotein E (ApoE)-ε4 is a risk factor for ischemic cerebrovascular diseases (ICVD), but the existence of this association is still controversial. The aims of this study were: (1) to compare ApoE genotype and allele frequencies in Italian cases with ICVD and in healthy control subjects and (2) to compare ApoE allele frequencies among ischemic stroke subtypes. Methods: A hospital-based cohort of 302 Italian subjects with ICVD and 228 healthy subjects have been recruited to investigate the role of ApoE polymorphisms as risk factors for ICVD. TOAST criteria were employed to stratify ICVD cases by subtypes. Results: No significant differences in ApoE genotype and allele frequencies were found between cases and control subjects. The frequency of ApoE-ε4 was lower in cases than in control subjects (6% vs. 10.1%), although not significantly. No differences in ApoE genotype and allele frequencies were evident among ICVD subtypes. However, out of 36 ApoE-ε4 alleles 23 (3.7%) were found in subjects with ICVD related to primary degenerative arterial disease related to large vessel disease and small vessel disease, and 13 (2.1%) in remaining subjects. Using logistic regression analysis we assessed whether ApoE-ε4 allele was independently associated with risk of ICVD related to a primary degenerative arterial disease compared to other ICVD subtypes. While classical risk factors were significantly associated with higher risk for ICVD due to large vessel disease and small vessel disease than other ICVD subtypes, the role of ApoE-ε4 allele was not significant (OR 1.25, 95% CI 0.57–2.74). Conclusion: Our study shows similar ApoE-ε4 genotype and allele frequencies in patients with ICVD and in control subjects. No differences were found among different ICVD subtypes either.
Prostacyclin versus Citrate in Continuous Haemodiafiltration: An Observational Study in Patients with High Risk of Bleeding
Authors: Balik M. , Waldauf P. , Plášil P. , Pachl J.
Published: August 2005

Background: The efficacy and safety of prostacyclin (PGI2) and citrate (ACD) anticoagulation were observed and compared during continuous haemodiafiltration. Methods: Mechanically ventilated patients received either the PGI2 analogue epoprostenol (group A, n = 17) in escalating doses of 4.5–10.0 ng·kg–1·min–1 in combination with heparin (6 IU·kg–1·h–1) or 2.2% ACD (group B, n = 15). Blood flow was set to match the circuit-filling volume per unit time equal to the intravascular half-life of PGI2. Results: Median filter lifetimes were 26 h (interquartile range 16–37) in group A (39 filters) and 36.5 h (interquartile range 23–50) in group B (56 filters; p < 0.01). In group A, 4 patients (23.5%, p < 0.05) had the dose reduced due to hypotension. The final mean dose of PGI2 was 8.7 ± 2.4 ng·kg–1·min–1. Four patients in group A (23.5%, p < 0.05) were switched to ACD due to a decrease in platelet count. No bleeding episodes, decrease in platelet count or adverse haemodynamic effects were encountered in group B. The cost of epoprostenol plus low dose heparin (EUR 204.73 ± 53.04) was significantly higher than the cost of ACD-based anticoagulation (EUR 93.92 ± 45.2, p < 0.05). Conclusion: ACD offers longer filter survival, has no impact on platelet count and is less expensive. Increasing the dose of PGI2 up to the average of 8.7 ng·kg–1·min–1 did not increase the haemodynamic side effects.
Convergence Time for the Linkage Learning Genetic Algorithm
Authors: Chen Ying-ping , Goldberg David E.
Published: August 2005

This paper identifies the sequential behavior of the linkage learning genetic algorithm, introduces the tightness time model for a single building block, and develops the connection between the sequential behavior and the tightness time model. By integrating the first-building-block model based on the sequential behavior, the tightness time model, and the connection between these two models, a convergence time model is constructed and empirically verified. The proposed convergence time model explains the exponentially growing time required by the linkage learning genetic algorithm when solving uniformly scaled problems.
Gas tungsten arc welding of titanium using flux cored wire with magnesium fluoride
Authors: Bang K.-S. , Chirieleison G. , Liu S.
Published: August 2005

Grade 2 Ti–CP was gas tungsten arc welded using flux cored (FC) wires and flux pastes that contained various MgF2 contents. The effects of MgF2 on bead morphology, chemical composition and hardness of weld bead were investigated and interpreted. With an increase of MgF2 content in the flux paste, depth/width ratio of weld bead increased gradually with little variation in interstitial element contents and hardness. Weld bead made with cold FC wire feed showed even deeper and narrower bead, indicating the greater effectiveness of wire feed than flux paste on weld penetration. While the 50% MgF2 FC wire produced complete slag coverage and smooth weld bead surface, 85% MgF2 wire resulted in incomplete slag coverage and rough weld surface. Arc spectroscopy revealed that the 50% MgF2 FC wire produced plasma spectrum with atomic and ionised titanium peaks, which is an indication of a high temperature arc and a larger amount of flux vapours in the arc. Therefore, it is believed that deep weld penetration associated with high MgF2 fluxes in this experiment is caused by arc constriction, resulting from the greater amount of flux vapours owing to high arc temperature.
Immunomodulatory dendritic cells require autologous serum to circumvent nonspecific immunosuppressive activity in vivo
Authors: Haase Claus , Ejrnaes Mette , Juedes Amy E. , Wolfe Tom , Markholst Helle , von Herrath Matthias G.
Published: August 2005

In immunotherapy, dendritic cells (DCs) can be used as powerful antigen-presenting cells to enhance or suppress antigen-specific immunity upon in vivo transfer in mice or humans. However, to generate sufficient numbers of DCs, most protocols include an ex vivo culture step, wherein the cells are exposed to heterologous serum and/or antigenic stimuli. In mouse models of virus infection and virus-induced autoimmunity, we tested how heterologous serum affects the immunomodulatory capacity of immature DCs generated in the presence of IL-10 by comparing fetal bovine serum (FBS)- or normal mouse serum (NMS)-supplemented DC cultures. We show that FBS-exposed DCs induce a systemic immune deviation characterized by reduction of virus-specific T cells, delayed viral clearance, and enhanced systemic production of interleukin 4 (IL-4), IL-5, and IL-10 to FBS-derived antigens, including bovine serum albumin (BSA). By contrast, DCs generated in NMS-supplemented cultures modulated immunity and autoimmunity in an antigen-specific fashion. These cells did not induce systemic IL-4, IL-5, or IL-10 production and inhibited generation of virus-specific T cells or autoimmunity only if pulsed with a viral antigen. These data underscore the importance of using autologous serum-derived immature DCs in preclinical animal studies to accurately assess their immunomodulatory potential in future human therapeutic settings, where application of FBS is not feasible.
Ribosomal intergenic spacer (IGS) length variation across the Drosophilinae (Diptera: Drosophilidae)
Authors: Mateos Mariana , Markow Therese A
Published: August 2005

Background

The intergenic spacer of the ribosomal genes in eukaryotes (IGS) contains duplications of the core transcription promoter. The number of these duplicated promoters, as measured by the IGS length, appears to be correlated with growth rate and development time in several distantly related taxa. In the present study, we examined IGS length variation across a number of species ofDrosophilato determine the amount of variation in this trait across different evolutionary time scales. Furthermore, we compared the usefulness of two methods commonly used to determine IGS length: Southern Blot Hybridization (SB) and Polymerase Chain Reaction (PCR).

Results

Our results show broad variation in IGS length across the genusDrosophila, but closely related species had similar IGS lengths. Our results also suggest that PCR tends to underestimate the true IGS size when the size is greater than 5 kb, and that this degree of underestimation is greater as the IGS size increases.

Conclusion

Broad variation in IGS length occurs across large evolutionary divergences in the subfamily Drosophilinae. Although average IGS length has been shown to evolve rapidly under artificial selection, closely related taxa generally have similar average IGS lengths. Our comparison of methods suggests that without previous knowledge of the DNA sequence of the IGS and flanking regions, both methods be used to accurately measure IGS length.
Adenocarcinoma in bladder diverticulum, metastatic from gastric cancer
Authors: Matsuhashi Nobuhisa , Yamaguchi Kazuya , Tamura Taiso , Shimokawa Kuniyasu , Sugiyama Yasuyuki , Adachi Yosuke
Published: August 2005

Background

Metastasis to the urinary bladder from gastric cancer is rare. Metastasis to a diverticulum of the bladder from gastric cancer is extremely rare. We report a case of isolated bladder metastasis from gastric cancer and invasion localized to the muscularis propria of the primary site (stomach).

Case presentation

A 90-year-old female presented with nausea and vomiting that was diagnosed as gastric cancer, the patient also had intermittent hematuria. Pelvic computed tomography identified an abnormally thickened area in the bladder wall that was diagnosed as a diverticulum of the bladder. A biopsy of the bladder wall revealed well differentiated tubular adenocarcinoma metastatic from gastric carcinoma.

Conclusion

Almost all cases of bladder metastasis from gastric cancer had peritoneal dissemination. This particular presentation of bladder metastasis from gastric cancer, to the best of our knowledge, has not been previously reported.
Catheter-related septic thrombophlebitis of the great central veins successfully treated with low-dose streptokinase thrombolysis and antimicrobials
Authors: Volkow Patricia , Cornejo-Juárez Patricia , Arizpe-Bravo Ana Berta , García-Méndez Jorge , Baltazares-Lipp Enrique , Pérez-Padilla Rogelio
Published: August 2005

Background

Septic thrombophlebitis is an iatrogenic life-threatening disease associated with use of central venous devices and intravenous (IV) therapy. In cancer patients receiving chemotherapy, vein resection or surgical thrombectomy in large central venous lines is time-consuming, can delay administration of chemotherapy, and therefore can compromise tumor control. Experience with thrombolysis has been published for catheter-related thrombosis but for septic thrombosis, this experience is scarce.

Results

We describe three patients with cancer and septic thrombophlebitis of central veins caused by Staphylococcus aureus treated with catheter removal, thrombolysis, and intravenous (IV) antibiotics. In our reported cases, an initial bolus of 250,000 international units (IU) of streptokinase administered during the first h followed by an infusion of 20,000–40,000 IU/h for 24–36 h through a proximal peripheral vein was sufficient to dissolve the thrombus. After thrombolyisis and parenteral antibiotic for 4–6 weeks the septic thrombosis due to Staphylococcus aureus solved in all cases. No surgical procedure was needed, and potential placement of a catheter in the same vein was permitted.

Conclusion

Thrombolysis with streptokinase solved symptoms, cured infection, prevented embolus, and in all cases achieved complete thrombus lysis, avoiding permanent central-vein occlusion.
Analysis of blood coagulation in mice: pre-analytical conditions and evaluation of a home-made assay for thrombin-antithrombin complexes
Authors: Sommeijer Dirkje W , van Oerle René , Reitsma Pieter H , Timmerman Janneke J , Meijers Joost CM , Spronk Henri MH , ten Cate Hugo
Published: August 2005

Background

The use of mouse models for the study of thrombotic disorders has gained increasing importance. Methods for measurement of coagulation activation in mice are, however, scarce. The primary aim of this study was to develop a specific mouse thrombin-antithrombin (TAT) ELISA for measurement of coagulation activation and to compare it with two commercially available assays for human TAT complexes. In addition, we aimed to improve methods for mouse plasma anticoagulation and preparation.

Methods and results

First, for the measurement of TAT-complexes in plasma a mouse specific TAT-ELISA was developed using rabbit polyclonal antibodies raised against mouse thrombin and rat antithrombin, respectively. This ELISA detected an increase in TAT levels in a mouse model of endotoxemia. Two commercial human TAT ELISAs appeared to be less specific for mouse thrombin-rat antithrombin complexes.

Second, to prevent clotting of mouse blood sodium citrate was either mixed with blood during collection in a syringe or was injected intravenously immediately prior to blood collection. Intravenous sodium citrate completely inhibited blood coagulation resulting in plasma with consistently low TAT levels. Sodium citrate mixed with blood during collection resulted in increased TAT levels in 4 out of 16 plasma samples. Third, heparinase was added to plasma samples after in vivo injection of different heparin doses to test its neutralizing effect. Heparinase neutralized up to a 20 U of heparin/mouse and resulted in accurate APTT and factor VIII determinations.

Conclusion

These procedures and reagents for plasma preparation and coagulation testing will improve studies on thrombotic disorders in mice.
Strengthening Medicare: Will increasing the bulk-billing rate and supply of general practitioners increase access to Medicare-funded general practitioner services and does rurality matter?
Authors: Day Susan E , Alford Katrina , Dunt David , Peacock Stuart , Gurrin Lyle , Voaklander Don
Published: August 2005

Background

Recent increases in the bulk-billing rate have been taken as an indication that the Federal government'sStrengthening Medicareinitiative, and particularly the bulk-billing incentives, are 'working'. Given the enduring geographic differences in the supply of general practitioners (GPs) it is timely to reconsider the impact that this increase in the provision of 'free care' will have on access to Medicare-funded GP services in rural and urban areas of Australia. Utilisation has been modelled as two different stochastic processes: the decision to consult and the frequency of consultation.

Results

In the decision to consult model the supply of FFS GPs is a more important predictor of utilisation than the bulk-billing rate. Paradoxically the modelling predicts that ceteris paribus increases in either GP supply or the bulk-billing rate appear to have perverse effects in some areas by decreasing utilisation. In the frequency of consultation model, GP density is not a predictor and increasing the bulk-billing rate will unambiguously increase the frequency of consultation across all areas. In both models, the positive impacts associated with changes in supply and cost are constrained outside the inner metropolitan area by reduced geographic accessibility to Medicare-funded GP services. The modelling also shows that people are more likely to consult a GP in areas of high socioeconomic disadvantage, although socioeconomic status is not a predictor of frequency of consultation.

Conclusion

Bulk-billing rates and the supply of FFS GPs are important features of the Australian health care system that are, potentially, amenable to policy manipulation. The implications of this research are that government policies designed to achieve similarity in these characteristics across geographic areas will not result in equity of access because they fail to address problems caused by geographic inaccessibility in rural and remote areas. Attempting to increase bulk-billing rates in some of these areas may, in fact, reduce access to FFS GP services.
Ca2+ dynamics in salivary acinar cells: distinct morphology of the acinar lumen underlies near-synchronous global Ca2+ responses
Authors: Larina Olga , Thorn Peter
Published: August 2005

In salivary acinar cells, the pattern of the Ca2+ signals that regulates fluid and enzyme secretion has yet to be resolved, as there are conflicting reports in the literature. We have used a two-photon technique to directly visualize the acinar cell lumen in living fragments of exocrine tissue and simultaneously recorded agonist-induced changes in intracellular Ca2+. We show near-synchronous global Ca2+ responses in submandibular acinar cells, distinct from the typical apical to basal Ca2+ wave usually seen in rodent pancreatic acinar cells. In an effort to explain the basis of these near-synchronous global Ca2+ responses we used immunocytochemical experiments to localize luminal proteins and inositol trisphosphate receptors (InsP3Rs) in tissue fragments. Zona occludens 1 (ZO-1), a tight junction protein, shows that individual submandibular acinar cells are often nearly completely encircled by a narrow luminal structure. By contrast, in pancreatic fragments, ZO-1 staining shows short luminal branches terminating abruptly at the apical pole of single acinar cells. Co-immunostaining of InsP3Rs type 2 and type 3 showed them in the same region as ZO-1 in both exocrine tissues. Functional experiments showed that the near-synchronous global Ca2+ responses were still observed in the absence of extracellular Ca2+ and also in the presence of ryanodine. We conclude that the elaborate luminal region of submandibular cells leads to a hitherto unrecognized extensive distribution of InsP3Rs in a band around the cell and that this underlies the near-synchronous global Ca2+ response to agonists. We suggest that this may be a structural adaptation in submandibular cells to support the copious amounts of fluid secreted.
Unrestricted accessibility of short oligonucleotides to RNA
Authors: GAMPER HOWARD B. , ARAR KHALIL , GEWIRTZ ALAN , HOU YA-MING
Published: August 2005

The propensity of RNA to fold into higher-order structures poses a major barrier to the use of short probes (<15 nucleotides) by preventing their accessibility. Introduction of the pseudo-complementary bases 2-aminoadenine (nA) and 2-thiouracil (sU) and the destabilizing base 7-deazaguanine (cG) into RNA provides a partial solution to this problem. While complementary in hydrogen bonding groups, nA and sU cannot form a stable base pair due to steric hindrance, and are thus pseudo-complementary. Each, however, recognizes the regular T/U and A complements, allowing pairing with oligonucleotides. Short pseudo-complementary RNAs can be prepared by in vitro transcription. Relative to standard transcripts, the modified transcripts possess reduced secondary structure and increased accessibility to short (8-mer) probes in the locked nucleic acid (LNA) configuration. They also hybridize to complementary probes with increased specificity and thermostability. Practical application of this strategy to oligonucleotide-based hybridization assays will require engineering of RNA polymerase for more efficient utilization of pseudo-complementary nucleoside triphosphates.
Steady-State and Decay Characteristics of Protein Tryptophan Fluorescence from Bacteria
Authors: Dalterio R. A. , Nelson W. H. , Brut D. , Sperry J. , Psaras D. , Tanguay J. F. , Suib S. L.
Published: August 2005

The intrinsic steady-state fluorescence and fluorescence decay of Staphylococcus epidermidis, Pseudomonas fluorescens, Enterobacter cloacae, Escherichia coli, and Bacillus subtilis have been observed. Each organism exhibits a strong maximum in its emission spectrum at 330–340 nm when excited at 290 nm. Iodide quenching and denaturization experiments with 8 M urea provide strong evidence for the assignment of the 330–340-nm fluorescence to protein tryptophan. Most importantly, the decay of this bacterial protein-tryptophan fluorescence has been described by two exponential functions in all cases. The observation that characteristic protein-tryptophan fluorescence lifetimes have been obtained for each organism suggests that measurements of fluorescence lifetimes may be helpful in the rapid characterization of bacteria. Direct application will most likely be found in combination with the measurement of other luminescence parameters.
The Infrared Spectra of Dichloroacetic Acid Derivatives: Characteristic Absorption Frequencies of the -CHCl2 Group
Authors: Katon J. E. , Stout Thomas H. , Hess George G.
Published: August 2005

The infrared spectra of seven compounds containing the -CHCl2 group attached to various carbonyl functionalities have been carefully recorded under a variety of conditions. Group frequency ranges for the CH, CC, and CCl (two) stretching modes and two CH bending modes have been developed. With the exception of the CC stretching mode, these vibrations fall in rather narrow regions of the spectrum. The conformational equilibria present in chlorine-substituted acetic acid derivatives are reflected by their infrared spectra in various ways. The situation with regard to the observed carbonyl stretching frequencies as related to conformational equilibria is reviewed.
Holographic Grating Spectrometers: Wood's Anomalies, Spectral Response Functions, and Their Dependence on Groove Density
Authors: Malyj M. , Griffiths J. E.
Published: August 2005

Presented is a study of plane holographic gratings with sinusoidal groove profiles, focusing attention on the dependence of grating efficiency on groove density. Experimental spectral response curves are given for a number of gratings with different groove densities in an additive-dispersion double monochromator designed for work at visible wavelengths. The Wood's anomalies, both order-passing and resonance type, are characterized in each case. Simple equations are derived for predicting order-passing wavelengths given a fixed angle of deviation between the incident beam and the observed diffraction order. The trend in the strength of the anomalies is compared with theoretical calculations.
Morphological Correlates of Corticosteroid-Induced Changes in Prefrontal Cortex-Dependent Behaviors
Authors: Cerqueira João J. , Pêgo José M. , Taipa Ricardo , Bessa João M. , Almeida Osborne F. X. , Sousa Nuno
Published: August 2005

Imbalances in the corticosteroid milieu have been implicated in several neuropsychiatric disorders, including depression and schizophrenia. Prefrontal cortex (PFC) dysfunction is also a hallmark of these conditions, causing impairments in executive functions such as behavioral flexibility and working memory. Recent studies have suggested that the PFC might be influenced by corticosteroids released during stress. To test this possibility, we assessed spatial working memory and behavioral flexibility in rats submitted to chronic adrenalectomy or treatment with corticosterone (25 mg/kg) or the synthetic glucocorticoid dexamethasone (300 μg/kg); the behavioral analysis was complemented by stereological evaluation of the PFC (prelimbic, infralimbic, and anterior cingulate regions), the adjacent retrosplenial and motor cortices, and the hippocampal formation. Dexamethasone treatment resulted in a pronounced impairment in working memory and behavioral flexibility, effects that correlated with neuronal loss and atrophy of layer II of the infralimbic, prelimbic, and cingulate cortices. Exposure to corticosterone produced milder impairments in behavioral flexibility, but not in working memory, and reduced the volume of layer II of all prefrontal areas. Interestingly, adrenalectomy-induced deleterious effects only became apparent on the reverse learning task and were not associated with structural alterations in the PFC. None of the experimental procedures influenced the morphology of retrosplenial or motor cortices, but stereological measurements confirmed previously observed effects of corticosteroids on hippocampal structure. Our results describe, for the first time, that imbalances in the corticosteroid environment can induce degeneration of specific layers of the PFC; these changes appear to be the morphological correlate of corticosteroid-induced impairment of PFC-dependent behavior(s).
Effect of aqueous acetic, oxalic and carbonic acids on the adsorption of americium onto α-alumina
Authors: Alliot Cyrille , Bion Lionel , Mercier Florence , Vitorge Pierre , Toulhoat Pierre
Published: August 2005

The prediction of the migration for radionuclides in geologic media requires a quantitative knowledge of retardation phenomena. For this purpose, the sorption of Am(III) onto a model mineral — α-alumina — is studied here, including the effects of groundwater chemistry: pH and concentrations of small organic ligands (acetate, oxalate and carbonate anions). This work presents some experimental evidences for the synergic sorption mechanism of americium–ligand cationic complexes onto the alumina. As its anionic complexes were not sorbed, Am(III) cations were desorbed as a result of the formation of anionic complexes in the aqueous phase. By using the ion-exchange theory, and a corresponding restricted set of parameters — exchange capacities and thermodynamic equilibrium constants — the whole set of sorption experiments of Am(III) cationic species onto the α-alumina was modelled in various chemical conditions.
Fluoxetine-Resistance Genes inCaenorhabditis elegansFunction in the Intestine and May Act in Drug Transport
Authors: Choy Robert K M , Kemner John M , Thomas James H
Published: August 2005

Fluoxetine (Prozac) is one of the most widely prescribed pharmaceuticals, yet important aspects of its mechanism of action remain unknown. We previously reported that fluoxetine and related antidepressants induce nose muscle contraction of C. elegans. We also reported the identification and initial characterization of mutations in seven C. elegans genes that cause defects in this response (Nrf, nose resistant to fluoxetine). Here we present genetic evidence that the known nrf genes can be divided into two subgroups that confer sensitivity to fluoxetine-induced nose contraction by distinct pathways. Using both tissue-specific promoters and genetic mosaic analysis, we show that a gene from one of these classes, nrf-6, functions in the intestine to confer fluoxetine sensitivity. Finally, we molecularly identify nrf-5, another gene in the same class. The NRF-5 protein is homologous to a family of secreted lipid-binding proteins with broad ligand specificity. NRF-5 is expressed in the intestine and is likely secreted into the pseudocoelomic fluid, where it could function to transport fluoxetine. One model that explains these findings is that NRF-5 binds fluoxetine and influences its presentation or availability to in vivo targets.
CBT1 Interacts Genetically With CBP1 and the Mitochondrially Encoded Cytochrome b Gene and Is Required to Stabilize the Mature Cytochrome b mRNA of Saccharomyces cerevisiae
Authors: Ellis Timothy P , Schonauer Melissa S , Dieckmann Carol L
Published: August 2005

Mutation of a CCG sequence in the 5′-untranslated region of the mitochondrially encoded cytochrome b mRNA in Saccharomyces cerevisiae results in destabilization of the message and respiratory deficiency of the mutant strain. This phenotype mimics that of a mutation in the nuclear CBP1 gene. Here it is shown that overexpression of the nuclear CBT1 gene, due to a transposon insertion in the 5′-untranslated region, rescues the respiratory defects resulting from mutating the CCG sequence to ACG. Overexpressing alleles of CBT1 are allelic to soc1, a previously isolated suppressor of cbp1ts-induced temperature sensitivity of respiratory growth. Quantitative primer extension analysis indicated that cbt1 null strains have defects in 5′-end processing of precursor cytochrome b mRNA to the mature form. Cbt1p is also required for stabilizing the mature cytochrome b mRNA after 5′ processing.
Activation of an Alternative, Rec12 (Spo11)-Independent Pathway of Fission Yeast Meiotic Recombination in the Absence of a DNA Flap Endonuclease
Authors: Farah Joseph A , Cromie Gareth , Davis Luther , Steiner Walter W , Smith Gerald R
Published: August 2005

Spo11 or a homologous protein appears to be essential for meiotic DNA double-strand break (DSB) formation and recombination in all organisms tested. We report here the first example of an alternative, mutationally activated pathway for meiotic recombination in the absence of Rec12, the Spo11 homolog of Schizosaccharomyces pombe. Rad2, a FEN-1 flap endonuclease homolog, is involved in processing Okazaki fragments. In its absence, meiotic recombination and proper segregation of chromosomes were restored in rec12Δ mutants to nearly wild-type levels. Although readily detectable in wild-type strains, meiosis-specific DSBs were undetectable in recombination-proficient rad2Δ rec12Δ strains. On the basis of the biochemical properties of Rad2, we propose that meiotic recombination by this alternative (Rec*) pathway can be initiated by non-DSB lesions, such as nicks and gaps, which accumulate during premeiotic DNA replication in the absence of Okazaki fragment processing. We compare the Rec* pathway to alternative pathways of homologous recombination in other organisms.
Evidence of Meiotic Crossover Control in Saccharomyces cerevisiae Through Mec1-Mediated Phosphorylation of Replication Protein A
Authors: Bartrand Amy J , Iyasu Dagmawi , Marinco Suzanne M , Brush George S
Published: August 2005

Replication protein A (RPA) is the major single-stranded DNA-binding protein in eukaryotes, essential for DNA replication, repair, and recombination. During mitosis and meiosis in budding yeast, RPA becomes phosphorylated in reactions that require the Mec1 protein kinase, a central checkpoint regulator and homolog of human ATR. Through mass spectrometry and site-directed mutagenesis, we have now identified a single serine residue in the middle subunit of the RPA heterotrimer that is targeted for phosphorylation by Mec1 both in vivo and in vitro. Cells containing a phosphomimetic version of RPA generated by mutation of this serine to aspartate exhibit a significant alteration in the pattern of meiotic crossovers for specific genetic intervals. These results suggest a new function of Mec1 that operates through RPA to locally control reciprocal recombination.