bluuebunny/crossref_metadata_2025 huggingface dataset:
Absence of Association of Autoinducer‐2‐Based Quorum Sensing with Heat and Acid Resistance of Salmonella
Authors: Yoon Yohan , Sofos John N.
Published: September 2010

Abstract:  This study used various approaches to investigate the potential association of autoinducer‐2 (AI‐2) presence with thermal and acid resistance of Salmonella cultures. Salmonella Thompson strains RM1987N (luxS‐positive; AI‐2 positive) and RM1987NLUX (luxS‐negative; AI‐2 negative) were exposed to 55 °C (6 h) in Luria‐Bertani (LB) broth, while the luxS‐negative S. Thompson strain and a Salmonella Typhimurium luxS‐positive strain were exposed to 55 °C in AI‐2‐positive or ‐negative preconditioned (PC) media derived from S. Thompson and Escherichia coli O157:H7 luxS‐positive and ‐negative strains. In addition, the luxS‐negative S. Thompson strain was subjected to pH 3.5 PC media (35 °C, 6 h) with or without AI‐2 activity, and acid‐adapted or nonadapted S. Thompson strains were exposed to pH 3.0 LB broth (35 °C, 6 h). Surviving bacterial populations during exposure to 55 °C LB were not different between luxS‐negative and ‐positive S. Thompson strains. In addition, heating at 55 °C of the luxS‐negative S. Thompson strain in AI‐2‐positive and ‐negative PC media resulted in similar (P≥ 0.05) survivor counts. Furthermore, surviving cell counts of S. Typhimurium (luxS‐positive) in 55 °C AI‐2‐positive PC media were not different (P≥ 0.05) than those in AI‐2 negative PC media. No differences in surviving cell counts of the luxS‐negative S. Thompson strain was found when exposed to pH 3.5 AI‐2‐positive and ‐negative PC media. Also, survivors of acid‐adapted or nonadapted cells of luxS‐negative and ‐positive S. Thompson strains were not different following exposure to pH 3.0 LB. The results indicated that, under the conditions of this study, AI‐2‐based quorum sensing did not appear to be associated with heat and acid resistance of Salmonella.
Gender and Diversity Topics Taught in Commission on Accreditation for Marriage and Family Therapy Education Programs
Authors: Winston Ebony Joy , Piercy Fred P.
Published: September 2010

This article explores how the topics of gender and diversity are being taught and defined in accredited marriage and family therapy programs through syllabi content analysis and interviews with selected faculty. We examined findings by program (master’s and doctoral) and type of training (those that taught specific gender and culture courses and those that attempted to infuse gender and culture throughout the curriculum). We examined 39 syllabi from 21 master’s and 18 doctoral training programs. In addition, we conducted 20 interviews with faculty members. (Eighteen were White/Caucasian, one was African American and one was Asian Indian.) Some variation in topic areas was found between master’s and doctoral programs and between those programs that offered specific course content and those that offered infused course content. However, qualitative interview data reflected many similarities. Particularly apparent was the level of commitment, transparency, and experiential learning methods professors used, regardless of program level or type.
Ligularia qiaojiaensis sp. nov. (Asteraceae) from Yunnan, China
Authors: Dong Hong‐Jin , Chen You‐Sheng
Published: September 2010

Ligularia qiaojiaensisY. S. Chen & H. J. Dong sp. nov., known from two localities in northeastern Yunnan province of China, is described, illustrated and compared with similar species.
Acute Recovery of Patellar Tendon From Heat-Induced Shrinkage and Its Inhibition by Cross-Linking
Authors: Aksan Alptekin , McGrath John J.
Published: September 2010

There are two important factors that accompany heat-induced shrinkage of collagenous tissues: mechanical property degradation and partial recovery from the shrunken length (elongation) upon returning to room temperature (defined here as acute recovery). These undesirable factors reduce the efficacy of thermal therapies. We applied chemical cross-linking adjuvant to thermal treatment on New Zealand White rabbit patellar tendon complexes to explore the feasibility of reducing the impact of these undesirable side-effects. Our results have shown that with exposure to 0.5% w/v glutaraldehyde solution during heating, the recovery response of the patellar tendon tissue was decreased, and the mechanical properties of the tissue were significantly improved.
Vacuum breakdown limit and quantum efficiency obtained for various technical metals using dc and pulsed voltage sources
Authors: Le Pimpec F. , Gough C. , Paraliev M. , Ganter R. , Hauri C. , Ivkovic S.
Published: September 2010

For the SwissFEL project, an advanced high gradient low emittance gun is under development. Reliable operation with an electric field, preferably above 125 MV/m at a 4 mm gap, in the presence of an ultraviolet laser beam, has to be achieved in a diode configuration in order to minimize the emittance dilution due to space charge effects. In the first phase, a dc breakdown test stand was used to test different metals with different preparation methods at voltages up to 100 kV. The authors show that gradient achieved for rough machined (Ra<200 nm) metal electrodes followed by an argon glow plasma are similar to the one obtained using a mirrorlike electrode (Ra<40 nm). In addition, high gradient stability tests were also carried out over several days in order to prove reliable spark-free operation with a minimum dark current. In the second phase, electrodes with selected materials were installed in the 250 ns full width at half maximum, 500 kV electron gun and tested for high gradient breakdown and for quantum efficiency using an ultraviolet laser. Routine electron beam operation, breakdown-free, at 50 MV/m (6 mm gap, 10 Hz repetition rate) at various charges is now achieved using different metal electrodes.
Deep GaN etching by inductively coupled plasma and induced surface defects
Authors: Ladroue J. , Meritan A. , Boufnichel M. , Lefaucheux P. , Ranson P. , Dussart R.
Published: September 2010

GaN etching was studied in Cl2/Ar plasmas as a function of process parameters. In addition, for a better understanding of the etching mechanisms, Langmuir probe measurements and optical emission spectroscopy were carried out. Etch rate was found to depend strongly on bias power. After optimization, an etch rate greater than 1000 nm/min was achieved. A second part of this work is dedicated to the etched surface defects. An original method to estimate GaN dislocation density and to localize nanopipes in the material is presented. Columnar defects could also appear with impurities in the etching reactor. The authors also present a possible formation mechanism of those columnar defects.
Dye-sensitized solar cells: Effect of Ar/O2 gas-flow ratio on the structural and morphological properties of facing-target sputter-deposited TiO2 electrode
Authors: Hossain M. F. , Takahashi T.
Published: September 2010

Nanocrystalline TiO2 films were deposited on SnO2:F (FTO) coated glass substrate by the facing-target sputtering technique. Ruthenium complex-based dye was used to sensitize TiO2 films and carbon paste coated on FTO glass was used as a counterelectrode. The dye-sensitized solar cell (DSC) performance was investigated with various sputtering Ar/O2 gas-flow ratios of 8:2, 7:3, and 6:4. The structure of TiO2 films has shown a penniform columnar structure and the morphology has the clear dependence on the gas-flow ratio. The DSC with TiO2 electrode deposited at 7:3 gas-flow ratio exhibits the highest photocurrent (4.74 mA/cm2), maximum photoelectric-conversion efficiency (1.38%), and incident photon-to-current efficiency (58.9%) at 520 nm. Moreover, this DSC shows a longer lifetime which implies low recombination rate.
The Genetic and Molecular Basis for Sunscreen Biosynthesis in Cyanobacteria
Authors: Balskus Emily P. , Walsh Christopher T.
Published: September 2010

Enzymes for Sunscreen Synthesis

Many fungi, cyanobacteria, algae, and other marine organisms can biosynthesize small molecules termed mycosporine and mycosporine-like amino acids (MAAs) that, among other functions, protect them from harmful UV exposure. A formulation containing MAAs is used as a sunscreen in skin care and cosmetic products.
Balskus and Walsh
(p.
1653
, published online 2 September) have now identified the gene cluster in a cyanobacterium that is responsible for MAA production. They expressed the cluster in
Escherichia coli
and characterized the four biosynthetic enzymes bio chemically. Two are adenosine triphosphate.dependent peptide bond.forming enzymes that catalyze imine bond formation through unusual mechanisms.
Diversity and complexity of angler behaviour drive socially optimal input and output regulations in a bioeconomic recreational-fisheries model
Authors: Johnston Fiona D. , Arlinghaus Robert , Dieckmann Ulf
Published: September 2010

In many areas of the world, recreational fisheries are not managed sustainably. This might be related to the omission or oversimplification of angler behaviour and angler heterogeneity in fisheries-management models. We present an integrated bioeconomic modelling approach to examine how differing assumptions about angler behaviour, angler preferences, and composition of the angler population altered predictions about optimal recreational-fisheries management, where optimal regulations were determined by maximizing aggregated angler utility. We report four main results derived for a prototypical northern pike ( Esox lucius ) fishery. First, accounting for dynamic angler behaviour changed predictions about optimal angling regulations. Second, optimal input and output regulations varied substantially among different angler types. Third, the composition of the angler population in terms of angler types was important for determining optimal regulations. Fourth, the welfare measure used to quantify aggregated utility altered the predicted optimal regulations, highlighting the importance of choosing welfare measures that closely reflect management objectives. A further key finding was that socially optimal angling regulations resulted in biological sustainability of the fish population. Managers can use the novel integrated modelling framework introduced here to account, quantitatively and transparently, for the diversity and complexity of angler behaviour when determining regulations that maximize social welfare and ensure biological sustainability.
Using food web model results to inform stock assessment estimates of mortality and production for ecosystem-based fisheries management
Authors: Gaichas Sarah K. , Aydin Kerim Y. , Francis Robert C.
Published: September 2010

Examining food web relationships for commercially important species enhances fisheries management by identifying sources of variability in mortality and production that are not included in standard single-species stock assessments. We use a static mass-balance model to evaluate relationships between species in a large marine ecosystem, the coastal Gulf of Alaska, USA. We focus on food web relationships for four case-study species: Pacific halibut ( Hippoglossus stenolepis ), longnose skate ( Raja rhina ), walleye pollock ( Theragra chalcogramma ), and squids (order Teuthoidea). For each, we present the species’ position within the food web, evaluate fishing mortality relative to predation mortality, and evaluate diet compositions. We find that high trophic level (TL) species, whether commercially valuable (halibut) or incidentally caught (skates), have mortality patterns consistent with single-species assessment assumptions, where fishing mortality dominates natural mortality. However, assessments for commercially valuable (pollock) or incidentally caught (squids) mid-TL species can be enhanced by including food web derived predation information because fishing mortality is small compared with high and variable predation mortality. Finally, we outline food web relationships that suggest how production of species may change with diet composition or prey availability.
Radial consolidation modelling incorporating the effect of a smear zone for a multilayer soil with downdrag caused by mandrel action
Authors: Rujikiatkamjorn Cholachat , Indraratna Buddhima
Published: September 2010

A system of prefabricated vertical drains with surcharge preloading is an effective method for promoting radial drainage and accelerated soil consolidation. A piecewise technique is employed to analyse the radial consolidation in a multilayer soil system to include (i) the effect of soil downdrag and (ii) a smear zone having linearly varying soil permeability. The effect of soil dragged down from the upper soil layer into the lower layer has been analysed in terms of the time required for consolidation. It can be seen that the consolidation of the multilayer soil depends on smear zone characteristics, the permeability ratio between upper and lower soil layers, penetration depth, and drain spacing. Design procedures are described with the help of an example.
Quantitative prop support estimation and remote monitor early warning for hard roof weighting at the Muchengjian Mine in China
Authors: Tan Yunliang , Zhao Tongbin , Xiao Yaxun
Published: September 2010

The complex coal seam structure and hard roof at the Muchengjian Mine were studied, and the equivalent tensile strength of the roof was determined by a retrospective analysis of similar roof cave-ins. The prop spacing or number of hydraulic props required per unit area were obtained by analyzing the roof caving span and thickness. The early warning threshold bedding vertical separation velocity for hard roof caving at the Muchengjian Coal Mine was determined to be about 14 mm/day, and the newly invented “bedding separation remote monitoring system” (BSRMS) was used for the first time for early warning of a roof fall. A total of 48 trials of early warning roof weighting were performed at the Muchengjian Mine. It was found that not only were all the early warnings accurate, but the support system was also safe and reliable.
Aqueous sodium hypochlorite mediated chemoselective oxidation of chalcogenides to monoxides and dioxides by microwave exposure
Authors: Khurana Jitender M. , Nand Bhaskara
Published: September 2010

A solvent-free, rapid, and highly selective oxidation of sulfides, selenides, and tellurides (chalcogenides) to the corresponding monoxides (sulfoxides, selenoxides, and telluroxides) or the corresponding dioxides (sulfones, selenones, and tellurones) has been developed using aqueous sodium hypochlorite on solid supports by exposure to microwave. Chemoselectivity and quantitative yields have been attained in most cases.
Syntheses of ruthenium(II)-4,4′-biimidazole complexes and their potential anti-tumour activity
Authors: Kennedy David C. , James Brian R.
Published: September 2010

Synthesis and characterization of the RuII complexes, [Ru(N−N)3][CF3SO3]2, where N−N is 4,4′-biimidazole (complex 1a) or 2,2′-dimethyl-4,4′-biimidazole (1b), and the dimethylsulfoxide complexes RuCl2(DMSO)2(N−N) are reported. The air-stable, water-soluble complexes were characterized by elemental analysis, 1H NMR and IR spectroscopies, mass spectrometry, and solution conductivity. Evidence is presented also for the existence of the diruthenium complexes Ru2Cl4(DMSO)4(N−N), but there are insufficient data for elucidation of their structure. The complexes (and cisplatin) were tested against human breast-cancer cells (MDA-MB-435S) using an in vitro MTT assay, a colorimetric determination of cell viability: 1a and 1b exhibit the lowest IC50 values of 18 ± 5 and 36 ± 5 µmol/L, respectively, with cisplatin exhibiting an IC50 value of 35 ± 5 µmol/L. Isolation of DNA from cells treated with a solution of the Ru species showed no evidence of DNA-binding to the metal, although examination of the cells indicated that Ru was being taken up into the cells.
Understanding the reversible anodic behaviour and fluorescence properties of fluorenylazomethines — A structure–property study
Authors: Barik Satyananda , Friedland Sayuri , Skene W. G.
Published: September 2010

A series of fluorenylazomethine dyads and triads were prepared by simple condensation between the corresponding amine and aldehyde fluorene derivatives. These compounds were prepared as model compounds for investigating the effects of substitution and electronic groups on both the electrochemical properties and fluorescence quantum yields. It was found that the oxidation potential could be decreased by both incorporating electron donating groups and increasing the degree of conjugation. It was further found that alkylation in the fluorene’s 9-position increased the azomethine degree of conjugation by forcing all the fluorene moieties to be coplanar with the azomethine bonds to which they are attached. Meanwhile, reversible radical cation behaviour was possible by substituting the terminal 2,2′-positions with atoms other than hydrogen. The radical cation was theoretically found to be distributed evenly across the fluorene, corroborating the reversible anodic behaviour with 2,2′-substitution. The fluorescence quantum yields of the azomethines were not found to be dependent on substitution. This was because the azomethine fluorescence was found to be quenched relative to their precursors regardless of substitution. The fluorescence could be restored at both low temperature and by acid protonation.
Naphthalene derivatives from Diospyros wallichii
Authors: Salae Abdul-Wahab , Karalai Chatchanok , Ponglimanont Chanita , Kanjana-Opas Akkharawit , Yuenyongsawad Supreeya
Published: September 2010

Three new naphthalene derivatives, 2-hydroxymethyl-1,5-dimethoxynaphthalen-4-ol (1), 2,2′-bis-hydroxymethyl-1,1′,5,5′-tetramethoxy-3,3′-binaphthalen-4,4′-diol (2), and 5,5′-dihydroxy-2,2′-dimethyl-7,7′-binaphthalen-1,1′,4,4′-tetraone (3), were isolated from the hexane and CH2Cl2 extracts of the roots and fruits of Diospyros wallichii , along with sixteen known compounds comprising nine naphthoquinones (4–12), a coumarin (13), and six triterpenes (14–19). The structures of these compounds were established on the basis of spectroscopic data and comparison with reported values. The antibacterial, antifungal, and cytotoxic activities of naphthalene derivatives were also reported.
Effects of repeated fertilization in a young spruce stand in central British Columbia
Authors: Brockley R. P.
Published: September 2010

Sustained growth responses and large reductions in rotation length can be achieved by repeatedly fertilizing young boreal forests. This paper reports the effects of different regimes and frequencies of fertilization on the foliar nutrition and growth of 10-year-old sub-boreal white spruce ( Picea glauca (Moench) Voss) in central British Columbia. Mean stand volume in treatment plots fertilized twice (at 6-year intervals) with N and B (totaling 400 kg N/ha and 3 kg B/ha) was 20 m3/ha (75%) greater than in the unfertilized control at year 12. Significantly larger stand volume gains (34 m3/ha, 128%) were obtained when S (totaling 100 kg S/ha) was added to this treatment. The inclusion of other nutrients (P, K, and Mg) with N, S, and B did not result in further incremental growth gains. When combined with other nutrients, yearly applications of 100–200 kg N/ha (totaling 1600 kg N/ha) produced 74 m3/ha (277%) more volume compared with the unfertilized stand at year 12. The large effects of fertilization on stand growth were accompanied by large increases in leaf area. Results indicate that repeated fertilization of young sub-boreal spruce forests may offer an excellent opportunity to increase fibre yield and reduce rotation length.
GLOBAL INNOVATION: AN ANSWER TO MITIGATE BARRIERS TO INNOVATION IN SMALL AND MEDIUM-SIZED ENTERPRISES?
Authors: BUSE STEPHAN , TIWARI RAJNISH , HERSTATT CORNELIUS
Published: September 2010

Innovations have acquired a key role in the growth and competition strategies of firms today. They are regarded as an essential tool for stimulating growth and enabling firms to master the competition brought about by the forces of globalization. However, in particular, many small and medium-sized enterprises (SMEs) in Western countries are facing insurmaintable barriers to innovation. To what extent might the concept of global innovation and, more specifically, the internationalization of research and development (R&D) be an answer to deal with these problems, is discussed in this paper. Based on empirical studies conducted by the authors in Germany, the paper presents results from research-in-progress and proposes a reference model for chances and challenges of global innovation activities.
MANAGEMENT OF INTELLECTUAL PROPERTY IN RESEARCH AND DEVELOPMENT: A SEARCH FOR SYSTEMS FROM THE VIEWPOINT OF RESEARCH AND TECHNOLOGY ORGANIZATIONS
Authors: KAISER LORENZ
Published: September 2010

The following discussion tries to identify the key factors and mechanisms for the management of IP in research and development (R&D). Considering some experiences gathered from different players in R&D, particularly institutes of the Fraunhofer Gesellschaft, a significant correlating starting point can be detected for the various R&D cooperation and schemes: By relying on a solid IP basis, R&D players can choose the most appropriate R&D cooperation and commercialization schemes to deal with meet their individual situations. The way of choosing a course is a matter of using the most individual IP management methods, a matter of puzzling, promising technologies with appropriate partnerships — at the right time. Diverse as these methods of choice are, there are nevertheless some basic considerations for IP management which may help to meet the challenges of the complex and demanding puzzling task. Most important seem to be continuous and diligent care for own IP, the creation and fostering of sustainable and enduring R&D networks, and the assessment of marketing chances. As practice shows, balanced and flexible cooperation between the research community and industry often proves to be the key to joint progress and, in the end, to successful innovation.
Effect of graded hypoxia on supraspinal contributions to fatigue with unilateral knee-extensor contractions
Authors: Goodall Stuart , Ross Emma Z. , Romer Lee M.
Published: September 2010

Supraspinal fatigue, defined as an exercise-induced decline in force caused by suboptimal output from the motor cortex, accounts for over one-quarter of the force loss after fatiguing contractions of the knee extensors in normoxia. We tested the hypothesis that the relative contribution of supraspinal fatigue would be elevated with increasing severities of acute hypoxia. On separate days, 11 healthy men performed sets of intermittent, isometric, quadriceps contractions at 60% maximal voluntary contraction to task failure in normoxia (inspired O2fraction/arterial O2saturation = 0.21/98%), mild hypoxia (0.16/93%), moderate hypoxia (0.13/85%), and severe hypoxia (0.10/74%). Electrical stimulation of the femoral nerve was performed to assess neuromuscular transmission and contractile properties of muscle fibers. Transcranial magnetic stimulation was delivered to the motor cortex to quantify corticospinal excitability and voluntary activation. After 10 min of breathing the test gas, neuromuscular function and cortical voluntary activation prefatigue were unaffected in any condition. The fatigue protocol resulted in ∼30% declines in maximal voluntary contraction force in all conditions, despite differences in time-to-task failure (24.7 min in normoxia vs. 15.9 min in severe hypoxia, P < 0.05). Potentiated quadriceps twitch force declined in all conditions, but the decline in severe hypoxia was less than that in normoxia ( P < 0.05). Cortical voluntary activation also declined in all conditions, but the deficit in severe hypoxia exceeded that in normoxia ( P < 0.05). The additional central fatigue in severe hypoxia was not due to altered corticospinal excitability, as electromyographic responses to transcranial magnetic stimulation were unchanged. Results indicate that peripheral mechanisms of fatigue contribute relatively more to the reduction in force-generating capacity of the knee extensors following submaximal intermittent isometric contractions in normoxia and mild to moderate hypoxia, whereas supraspinal fatigue plays a greater role in severe hypoxia.
Posttranslational modifications in histones underlie heat acclimation-mediated cytoprotective memory
Authors: Tetievsky Anna , Horowitz Michal
Published: September 2010

We have demonstrated that heat acclimation (AC) causes selective, long-lasting, transcriptional changes in cytoprotective and chromatin remodeling-associated genes, which maintain their AC transcriptome profile, despite the loss of the AC phenotype (Tetievsky et al. Physiol Genomics 34: 78–87, 2008). We postulated that AC memory involves upstream epigenetic information, which predisposes to rapid reacclimation (ReAC) and cytoprotective memory. Here we tested the hypothesis that posttranslational histone modifications are linked to this process. Rats subjected to AC (34°C for 2 or 30 days), deacclimation (DeAC; 24°C, 30 days), and ReAC (34°C, 2 days), and untreated controls were used. Histone H4 lysine acetylation and histone H3 acetylation and phosphorylation in the heat shock element (HSE) of the promoters of heat shock protein-70 ( hsp70) and -90 ( hsp90) genes were examined. Histone acetyltransferase recruitment of TIP60 (60-kDa histone acetyltransferase-interactive protein), the catalytic subunit of NuH4, was used to validate acetylation. Heat shock factor-1 (HSF-1)-HSE binding to the hsp70 and hsp90 genes was measured to confirm HSF-1 binding to euchromatin. Our results indicate that, while histone H3Ser10 phosphorylation occurred during the AC 2-day phase, AC constitutively elevated histone H4 acetylation in the HSE of hsp70 and hsp90 promoters. HSF-1-HSE binding was detected in the hsp70 gen e throughout AC-DeAC-ReAC. The hsp90 gene lacked HSF-1 binding during DeAC, but resumed a high binding level upon ReAC. HSP-90 is a critical cytoprotective protein, and the HSF-1- hsp90 binding profile matched levels of this protein. We conclude that, while early histone H3 phosphorylation is probably required for subsequent histone H4 acetylation, the constitutively acetylated histone H4 and the preserved euchromatin state throughout AC-DeAC-ReAC predispose to rapid cytoprotective acclimatory memory.
Allometry of the mammalian intracellular pulmonary surfactant system
Authors: Wirkes André , Jung Kristina , Ochs Matthias , Mühlfeld Christian
Published: September 2010

Alveolar epithelial (AE) surface area is closely correlated with body mass (BM) in mammals. The AE is covered by a surfactant layer produced by alveolar epithelial type II (AE2) cells. We hypothesized that the total number of AE2 cells and the volume of intracellular surfactant-storing lamellar bodies (Lb) are correlated with BM with a similar slope as AE surface area. We used light and electron microscopic stereology to estimate the number and mean volume of AE2 cells and the total volume of Lb in 12 mammalian species ranging from 2 to 3 g (Etruscan shrew) to 400–500 kg (horse) BM. The mean size of Lb was evaluated using the volume-weighted mean volume and the volume-to-surface ratio of Lb. The mean volume of AE2 cells was 500–600 μm3in most species, but was higher in Etruscan shrew, guinea pig, and human lung. The mean volume of Lb per AE2 cell was 80–100 μm3in most species, with the same exceptions as above. However, the total number of AE2 cells and the total volume of Lb were closely correlated with BM and exhibited an allometric relationship similar to the slope of AE surface area. The mean size of Lb was similar in all investigated species. In conclusion, the mean volume of AE2 cells and their Lb are independent of BM but show some interspecific variations. The adaptation of the intracellular surfactant pool size to BM is obtained by the variation of the number of AE2 cells in the lung.
High incidence of venous and arterial gas emboli at rest after trimix diving without protocol violations
Authors: Ljubkovic Marko , Marinovic Jasna , Obad Ante , Breskovic Toni , Gaustad Svein E. , Dujic Zeljko
Published: September 2010

SCUBA diving is associated with generation of gas emboli due to gas release from the supersaturated tissues during decompression. Gas emboli arise mostly on the venous side of circulation, and they are usually eliminated as they pass through the lung vessels. Arterialization of venous gas emboli (VGE) is seldom reported, and it is potentially related to neurological damage and development of decompression sickness. The goal of the present study was to evaluate the generation of VGE in a group of divers using a mixture of compressed oxygen, helium, and nitrogen (trimix) and to probe for their potential appearance in arterial circulation. Seven experienced male divers performed three dives in consecutive days according to trimix diving and decompression protocols generated by V-planner, a software program based on the Varying Permeability Model. The occurrence of VGE was monitored ultrasonographically for up to 90 min after surfacing, and the images were graded on a scale from 0 to 5. The performed diving activities resulted in a substantial amount of VGE detected in the right cardiac chambers and their frequent passage to the arterial side, in 9 of 21 total dives (42%) and in 5 of 7 divers (71%). Concomitant measurement of mean pulmonary artery pressure revealed a nearly twofold augmentation, from 13.6 ± 2.8, 19.2 ± 9.2, and 14.7 ± 3.3 mmHg assessed before the first, second, and the third dive, respectively, to 26.1 ± 5.4, 27.5 ± 7.3, and 27.4 ± 5.9 mmHg detected after surfacing. No acute decompression-related disorders were identified. The observed high gas bubble loads and repeated microemboli in systemic circulation raise questions about the possibility of long-term adverse effects and warrant further investigation.
Targeting the α Receptor for Platelet-Derived Growth Factor as a Primary or Combination Therapy in a Preclinical Model of Prostate Cancer Skeletal Metastasis
Authors: Russell Mike R. , Liu Qingxin , Fatatis Alessandro
Published: September 2010

Purpose: Platelet-derived growth factor α (PDGFRα) is highly expressed in primary prostate cancer and associated skeletal metastases. Here, we tested whether targeting this receptor could impair metastatic colonization and progression, as well as prolong survival, either as primary or as combination therapy.

Experimental Design: We used a preclinical animal model of metastasis in which PC3-ML human prostate cancer cells are inoculated directly in the blood circulation. First, the humanized, monoclonal antibody IMC-3G3 was administered to mice bearing established skeletal metastases. Second, we targeted the stromal PDGFRα with IMC-1E10, an antibody specific for the murine receptor. Third, IMC-3G3 and the bisphosphonate zoledronic acid (ZA), administered separately or in combination, were tested on the progression of skeletal lesions and overall survival. In addition, the ability of IMC-3G3 and ZA to impair initial colonization of the bone marrow by prostate cancer cells was investigated.

Results: The blockade of PDGFRα on prostate cancer cells by IMC-3G3 reduces the size of established skeletal metastases, whereas the IMC-1E10 antibody directed against the stromal PDGFRα fails to inhibit metastatic progression. IMC-3G3 and ZA, either separately or in combination, significantly slow tumor growth and seem to prolong survival. Lastly, the blockade of PDGFRα by IMC-3G3 inhibits the initial phase of bone colonization, whereas ZA is ineffective at this stage.

Conclusion: This study presents compelling evidence that targeting PDGFRα with IMC-3G3 delays the progression of early metastatic foci and reduces the size of more established lesions. In addition, IMC-3G3, either alone or in combination with ZA, prolongs survival in animal models. Clin Cancer Res; 16(20); 5002–10. ©2010 AACR.
A Comparison of the Short-Term Outcome in Patients with Acute Low-Tone Sensorineural Hearing Loss
Authors: Morita Shinya , Suzuki Masanobu , Iizuka Keiji
Published: September 2010

Purpose of the Study: We aimed to compare the short-term outcome of patients with acute low-tone sensorineural hearing loss (ALHL) treated with steroid alone, diuretics alone or combination treatment. Procedures: Between April 2000 and March 2009, we retrospectively reviewed the medical records of 156 patients with a diagnosis of ALHL. All patients were followed up until improvement or for 8 weeks from the initial examination. Patients were treated with steroid alone (n = 49), diuretics alone (n = 40), combination treatment (n = 46) or they received neither steroid nor diuretics (n = 21). Results: The steroid-diuretic combination therapy for ALHL showed significantly better results than the steroid or diuretic treatments alone (p < 0.05). There were no clinically significant differences in the outcome between the steroid- and diuretic-alone treatments. Conclusion and Message: The etiology of ALHL is described as both an endolymphatic hydrops and an autoimmunological mechanism so that, as expected, the steroid-diuretic combination therapy was more effective than the steroid or diuretic treatments alone.
New Technologies for the Identification of Novel Genetic Markers of Disorders of Sex Development (DSD)
Authors: Bashamboo A. , Ledig S. , Wieacker P. , Achermann J.C. , McElreavey K.
Published: September 2010

Although the genetic basis of human sexual determination and differentiation has advanced considerably in recent years, the fact remains that in most subjects with disorders of sex development (DSD) the underlying genetic cause is unknown. Where pathogenic mutations have been identified, the phenotype can be highly variable, even within families, suggesting that other genetic variants are influencing the expression of the phenotype. This situation is likely to change, as more powerful and affordable tools become widely available for detailed genetic analyses. Here, we describe recent advances in comparative genomic hybridisation, sequencing by hybridisation and next generation sequencing, and we describe how these technologies will have an impact on our understanding of the genetic causes of DSD.
Resistance to Acidic Environments of Caries-Associated Bacteria: Bifidobacterium dentium and Bifidobacterium longum
Authors: Nakajo K. , Takahashi N. , Beighton D.
Published: September 2010

Oral Bifidobacteriaceae, Bifidobacterium dentium and Bifidobacterium longum, are known to be isolated together with mutans streptococci and lactobacilli from caries lesions, suggesting that these Bifidobacteriaceae are caries associated and acid resistant. This study aimed to investigate effects of acidification on B. dentium and B. longum, and to compare them with those on Streptococcus mutans, Streptococcus sanguinis and Lactobacillus paracasei. Effects of acidification, growth ability in a complex medium at a pH of 4.0–8.0, cell viability in 2-morpholinoethanesulfonic acid monohydrate (MES)-KOH buffer at pH 4.0, as well as stability of intracellular pH (pHin) at an extracellular pH of 3.5–8.0 estimated using a fluorescent dye, 5(6)-carboxyfluorescein diacetate N-succinimidyl ester in MES-KOH, 3-(N-morpholino)propanesulfonic acid-KOH or N,N-bis(2-hydroxyethyl)glycine-KOH buffer, were investigated. B. longum grew as well as Streptococcus strains over a wide pH range, whereas B. dentium grew best in the narrow pH range around neutral. The cell viability of B. dentium decreased significantly after 2 h of acidification at a pH of 4.0, but this was significantly less than that of the Streptococcus and Lactobacillus species, whereas B. longum maintained almost 100% viability. The pHin was close to the extracellular pH at pH of 5.5–7.5 in the Bifidobacterium and Streptococcus strains, while at a pH of <5.0, the pHin was higher than the extracellular pH in all the strains, but the pHin maintenance ability of Bifidobacterium strains was higher than that of the Streptococcus strains. The high survival rate and pHin maintenance ability of bifidobacteria comparable to that of S. mutans in the acidic environment may account for why bifidobacteria exist as stable species in acidic caries lesions together with mutans streptococci.
Partial Liver Ischemia Is Followed by Metabolic Changes in the Normally Perfused Part of the Liver during Reperfusion
Authors: Kannerup A.-S. , Grønbæk H. , Funch-Jensen P. , Karlsen S. , Mortensen F.V.
Published: September 2010

Background: Temporary vascular in- and outflow occlusion is an effective technique for bleeding control during liver resection. However, occlusion can result in ischemia/reperfusion (I/R) injury to the liver. The aim of this study in a porcine model was to investigate the effect of in- and outflow occlusion of part of the liver on the metabolism of the normally perfused parenchyma of the same liver measured by microdialysis. Methods: Eight pigs underwent laparotomy. A microdialysis catheter was inserted into in the left and right part of the liver, respectively. Microdialysis samples were collected every 30 min. Occlusion of the left part of the liver was achieved for 60 min, followed by 5 h of reperfusion. Samples were analyzed for glucose, lactate, pyruvate and glycerol. Blood samples were drawn to determine standard liver and biochemical parameters. Results: Comparing the ischemic part of the liver with the normally perfused part, significant differences in the levels of lactate, pyruvate and glycerol were found. During reperfusion, similar and continuous decreases below baseline levels were observed for lactate and pyruvate in both the ischemic and normally perfused part of the liver. No significant changes in liver parameters or blood glucose levels were seen. Conclusions: Partial ischemia of the liver is without effects on metabolism in the normally perfused part. Metabolic changes in the ischemic part of the liver were reversible. However, partial liver ischemia was followed by similar continuous decreases in lactate and pyruvate levels in the whole liver, even though the ischemic insult was not detectable in transaminase levels.
Linguistic and Human Effects on F₀ in a Tonal Dialect of Qiang
Authors: Evans Jonathan , Chu Man-ni , Aston John A.D. , Su Chao-yu
Published: September 2010

While both human and linguistic factors affect fundamental frequency (F₀) in spoken language, capturing the influence of multiple effects and their interactions presents special challenges, especially when there are strict time constraints on the data-gathering process. A lack of speaker literacy can further impede the collection of identical utterances across multiple speakers. This study employs linear mixed effects analysis to elucidate how various effects and their interactions contribute to the production of F₀ in Luobuzhai, a tonal dialect of the Qiang language. In addition to the effects of speaker sex and tone, F₀ in this language is affected by previous and following tones, sentence type, vowel, position in the phrase, and by numerous combinations of these effects. Under less than ideal data collecting conditions, a single experiment was able to yield an extensive model of F₀ output in an endangered language of the Himalayas.
Advances in the Etiology of Chronic Pancreatitis
Authors: Lerch Markus M. , Mayerle Julia , Aghdassi Ali A. , Budde Christoph , Nitsche Claudia , Sauter Gabriele , Persike Maria , Günther Annett , Simon Peter , Weiss F. Ulrich
Published: September 2010

In the past, chronic pancreatitis has been regarded as a fairly uniform and largely untreatable disorder that most commonly affects patients who both lack gainful employment or adequate insurance coverage and have a tendency to smoke and drink. Large clinical trials suggest that this perception is not only misguided and discriminatory but also not based on facts. We forgot that the perception of chronic liver disease was similar before World War II, and just like liver cirrhosis the fibrosis and cirrhosis of the pancreas – i.e. chronic pancreatitis – is the end result of a range of environmental, inflammatory, infectious and genetic disorders. A growing number of these have only recently been recognized as a distinct entity and several of which are becoming truly treatable. A large proportion of the risk for developing pancreatitis is conveyed by genetic risk factors, and we estimate that less than half of those have been identified so far. The same holds true for protective factors that can prevent pancreatitis, even in the face of excessive alcohol abuse. Various gene mutations and polymorphisms appear to determine an individual’s susceptibility for developing pancreatic disease, for the severity of the disease, and for the disease progression. The spectrum of genotype/phenotype associations ranges from straightforward autosomal dominant traits with near-complete penetrance, as for the most common mutations in the cationic trypsinogen gene (PRSS1), to moderate risks factors without mendelian inheritance patterns, as for SPINK1 and CFTR mutations, to very subtle risk associations and disease modifiers that can only be identified in large cohort studies, as for the chymotrypsin C, calcium-sensing receptor and the anionic trypsin (PRSS2) mutations. Only a better understanding of the disease mechanisms that underlie these changes will make an individualized therapy of pancreatic disorders a realistic option.
Pancreatic Cancer: Epidemiology and Risk Factors
Authors: Krejs Guenter J.
Published: September 2010

Ductal adenocarcinoma of the pancreas has an incidence of approximately 10 per 100,000 population per year. This number pertains to Europe, North America and parts of South America (Argentina). Men are more often afflicted than women (female:male ratio of about 1:1.5, though reports vary). There has been a very small but steady increase in the incidence over the last 50 years. Unfortunately, numbers for incidence and mortality are still practically identical for this cancer. The peak of incidence is between 60 and 80 years of age. In absolute numbers, there are 8,000 cases diagnosed annually in Germany, and 33,000 in the US. Pancreatic cancer at <40 years of age is extremely rare (2 cases per million per year), but among 80-year-olds, the incidence is about 200 new cases per 100,000 population per year. In men, carcinoma of the pancreas is the fourth most common cause of cancer death after lung, prostate and colorectal cancer. In women, it is the fifth most common cause of cancer death. Risk factors for pancreatic cancer include high-fat diet, smoking, chronic pancreatitis, primary sclerosing cholangitis, hereditary pancreatitis, family history of pancreatic cancer and diabetes mellitus. In chronic pancreatitis, the risk for pancreatic cancer is increased 20-fold, in hereditary pancreatitis it is 60-fold higher than in the general population. In a kindred with 2 first-degree relatives with pancreatic cancer, the risk for pancreatic cancer for other members of that kindred is 7-fold higher.
Research Ethics in the Era of Personalized Medicine: Updating Science’s Contract with Society
Authors: Meslin Eric M. , Cho Mildred K.
Published: September 2010

With the completed sequence of the human genome has come the prospect of substantially improving the quality of life for millions through personalized medicine approaches. Still, any advances in this direction require research involving human subjects. For decades science and ethics have enjoyed an allegiance reflected in a common set of ethical principles and procedures guiding the conduct of research with human subjects. Some of these principles emphasize avoiding harm over maximizing benefit. In this paper we revisit the priority given to these ethical principles – particularly the principles that support a cautious approach to science – and propose a reframing of the ‘social contract’ between science and society that emphasizes reciprocity and meeting public needs.
TLQP-21, a VGF-Derived Peptide, Prevents Ethanol-Induced Gastric Lesions: Insights into Its Mode of Action
Authors: Sibilia Valeria , Pagani Francesca , Bulgarelli Ilaria , Mrak Emanuela , Broccardo Maria , Improta Giovanna , Severini Cinzia , Possenti Roberta , Guidobono Francesca
Published: September 2010

Background and Aim: TLQP-21, a peptide derived from the vgf gene, has been reported to play a role in the regulation of rat gastric motility, but its influence on gastric mucosal integrity is unknown. Experimental Approach: We investigated the effects of central (0.8–8 nmol/rat) or peripheral (48–240 nmol/kg) TLQP-21 administration on ethanol- (EtOH, 50%, 1 ml/rat) induced gastric lesions in the rat. The mechanisms involved in such activity were also examined. Results: Central TLQP-21 injection dose-dependently reduced EtOH-induced gastric lesions (ED50 = 3.16 nmol), while peripheral TLQP-21 administration had no effect. The TLQP-21 gastroprotective effect against EtOH injury was accompanied by a significant increase in gastric prostaglandin E2 (PGE2) production linked to an increase in constitutive cyclooxygenase (COX) expression. The nitric oxide (NO) synthase inhibitor L-NAME (70 mg/kg, s.c.), the nonselective COX inhibitor indomethacin (10 mg/kg, orally) and capsaicin denervation removed TLQP-21 gastroprotection. Conclusions: This study shows for the first time that central TLQP-21 exerts a protective action on the gastric mucosa exposed to the noxious agent EtOH. TLQP-21 gastroprotection is mediated by constitutive-derived NO and PGE2, and requires the integrity of sensory nerve fibers.
Association of Cumulatively Low or High Serum Calcium Levels with Mortality in Long-Term Hemodialysis Patients
Authors: Miller Jessica E. , Kovesdy Csaba P. , Norris Keith C. , Mehrotra Rajnish , Nissenson Allen R. , Kopple Joel D. , Kalantar-Zadeh Kamyar
Published: September 2010

Background: The outcome-predictability of baseline and instantaneously changing serum calcium in hemodialysis patients has been examined. We investigated the mortality-predictability of time-averaged calcium values to reflect the ‘cumulative’ effect of calcium burden over time. Methods: We employed a Cox model using up-to-5-year (7/2001–6/2006) time-averaged values to examine the mortality-predictability of cumulative serum calcium levels in 107,200 hemodialysis patients prior to the use of calcimimetics, but during the time where other calcium-lowering interventions, including lower dialysate calcium, were employed. Results: Both low (<9.0 mg/dl) and high (>10.0 mg/dl) calcium levels were associated with increased mortality (reference: 9.0 to <9.5 mg/dl). Whereas mortality of hypercalcemia was consistent, hypocalcemia mortality was most prominent with higher serum phosphorus (>3.5 mg/dl) and PTH levels (>150 pg/ml). Higher paricalcitol doses shifted the calcium range associated with the greatest survival to the right, i.e. from 9.0 to <9.5 to 9.5 to <10.0 mg/dl. African-Americans exhibited the highest death hazard ratio of hypocalcemia <8.5 mg/dl, being 1.35 (95% CI: 1.22–1.49). Both a rise and drop in serum calcium over 6 months were associated with increased mortality compared to the stable group. Conclusions: Whereas in hemodialysis patients cumulatively high or low calcium levels are associated with higher death risk, subtle but meaningful interactions with phosphorus, PTH, paricalcitol dose and race exist.