bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of antitussive efficacy of dextromethorphan in smoking related cough: objective vs. subjective measures
Authors: Ramsay James , Wright Caroline , Thompson Rachel , Hull David , Morice Alyn H.
Published: February 2008

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Dextromethorphan is widely used as a cough suppressant in over the counter medications.

• Its efficacy in altering cough reflex sensitivity has been shown in healthy volunteers. In contrast evidence for an effect on clinically important cough is poor.

WHAT THIS STUDY ADDS

• A significant decrease in evoked cough was seen with dextromethorphan compared with placebo. However, both placebo and active treatment improved subjective data to a similar degree.

• We doubt the validity of currently used objective tests in the investigation of antitussives.

AIMS

Using an established model of smokers cough we measured the antitussive effects of dextromethorphan compared with placebo.

METHODS

The study was a randomized, double‐blind placebo controlled, crossover comparison of 22 mg 0.8 ml−1 dextromethorphan delivered pregastrically with matched placebo. Objective and subjective measurements of cough were recorded. Subjective measures included a daily diary record of cough symptoms and the Leicester quality of life questionnaire. Cough frequency was recorded using a manual cough counter. The objective measure of cough reflex sensitivity was the citric acid, dose–response cough challenge.

RESULTS

Dextromethorphan was significantly associated with an increase in the concentration of citric acid eliciting an average of two coughs/inhalation (C2) when compared with placebo, 1 h post dose by 0.49 mM (95% CI 0.05, 0.45, geometric mean 3.09) compared with placebo 0.24 mM (geometric mean 1.74) P < 0.05 and at 2 h 0.57 mM (95% CI 0.01, 0.43, geometric mean 3.75) compared with placebo 0.34 mM (geometric mean 2.19) P < 0.05). There was a highly significant improvement in the subjective data when compared with baseline. However, there was no significant difference between placebo and active treatment. No correlation was seen between cough sensitivity to citric acid and recorded cough counts or symptoms. When both subjective and objective data were compared with screening data there was evidence of a marked ‘placebo’ effect.

CONCLUSIONS

The objective measure of cough sensitivity demonstrates dextromethorphan effectively diminishes the cough reflex sensitivity. However, subjective measures do not support this. Other studies support these findings, which may represent a profound sensitivity of the cough reflex to higher influences.
Mycorrhizal and rhizomorph dynamics in a loblolly pine forest during 5 years of free‐air‐CO2‐enrichment
Authors: PRITCHARD S. G. , STRAND A. E. , McCORMACK M. L. , DAVIS M. A. , OREN R.
Published: February 2008

Soil fungi couple plant and ecosystem resource demands to pools of soil resources. Research on these organisms is needed to predict how rising atmospheric CO2 will influence forest ecosystem processes and soil carbon (C) sequestration potential. We examined the influence of free‐air‐CO2‐enrichment (FACE) on mycorrhizal and extraradical rhizomorph dynamics over a 5‐year period in a loblolly pine forest using minirhizotrons. Standing crop of mycorrhizal root tips varied greatly spatially and through time. Summed across all years, CO2 enrichment increased mycorrhizal root tip production by 194% in deep soil (15–30 cm) but did not influence mycorrhizal production in shallow soil (0–15 cm). Production and mortality of soil rhizomorph length was 27% and 25% greater in CO2‐enriched plots compared with controls over a 5‐year period beginning in January of 2000 and running through autumn 2004. Effects of atmospheric CO2 enrichment on longevity of mycorrhizal root tips and rhizomorphs varied with soil depth (mycorrhizae and rhizomorphs) and with diameter (rhizomorphs). For instance, survival of mycorrhizal tips was reduced in CO2‐enriched plots in deep soil (15–30 cm depth) but was increased in shallower soil (0–15 cm). Rhizomorph turnover was accelerated in shallow soil but effects on survivorship in deep soil varied according to diameter. A drought in 2002 coupled with loss of leaf area to an ice storm late in 2002 were followed by reductions in rhizomorph and mycorrhizal production, increases in mortality, and decreases in standing crop during 2003 and 2004. These effects tended to be more severe in CO2‐enriched plots. Positive effects of atmospheric CO2 enrichment on mycorrhizal fungi, primarily observed in deeper soil, are probably contributing to the prolonged stimulation of NPP by CO2 enrichment at the Duke FACE study site.
The sensitivity of annual grassland carbon cycling to the quantity and timing of rainfall
Authors: CHOU WENDY W. , SILVER WHENDEE L. , JACKSON RANDALL D. , THOMPSON ANDREW W. , ALLEN‐DIAZ BARBARA
Published: February 2008

Global climate models predict significant changes to the rainfall regimes of the grassland biome, where C cycling is particularly sensitive to the amount and timing of precipitation. We explored the effects of both natural interannual rainfall variability and experimental rainfall additions on net C storage and loss in annual grasslands. Soil respiration and net primary productivity (NPP) were measured in treatment and control plots over four growing seasons (water years, or WYs) that varied in wet‐season length and the quantity of rainfall. In treatment plots, we increased total rainfall by 50% above ambient levels and simulated one early‐ and one late‐season storm. The early‐ and late‐season rain events significantly increased soil respiration for 2–4 weeks after wetting, while augmentation of wet‐season rainfall had no significant effect. Interannual variability in precipitation had large and significant effects on C cycling. We observed a significant positive relationship between annual rainfall and aboveground NPP across the study (P=0.01, r2=0.69). Changes in the seasonal timing of rainfall significantly affected soil respiration. Abundant rainfall late in the wet season in WY 2004, a year with average total rainfall, led to greater net ecosystem C losses due to a ∼50% increase in soil respiration relative to other years. Our results suggest that C cycling in annual grasslands will be less sensitive to changes in rainfall quantity and more affected by altered seasonal timing of rainfall, with a longer or later wet season resulting in significant C losses from annual grasslands.
Effect of soil water stress on soil respiration and its temperature sensitivity in an 18‐year‐old temperate Douglas‐fir stand
Authors: JASSAL RACHHPAL S. , BLACK T. ANDREW , NOVAK MICHAEL D. , GAUMONT‐GUAY DAVID , NESIC ZORAN
Published: February 2008

We analyzed 17 months (August 2005 to December 2006) of continuous measurements of soil CO2 efflux or soil respiration (RS) in an 18‐year‐old west‐coast temperate Douglas‐fir stand that experienced somewhat greater than normal summertime water deficit. For soil water content at the 4 cm depth (θ) > 0.11 m3 m−3 (corresponding to a soil water matric potential of −2 MPa), RS was positively correlated to soil temperature at the 2 cm depth (TS). Below this value of θ, however, RS was largely decoupled from TS, and evapotranspiration, ecosystem respiration and gross primary productivity (GPP) began to decrease, dropping to about half of their maximum values when θ reached 0.07 m3 m−3. Soil water deficit substantially reduced RS sensitivity to temperature resulting in a Q10 significantly < 2. The absolute temperature sensitivity of RS (i.e. dRS/dTS) increased with θ up to 0.15 m3 m−3, above which it slowly declined. The value of dRS/dTS was nearly 0 for θ < 0.08 m3 m−3, thereby confirming that RS was largely unaffected by temperature under soil water stress conditions. Despite the possible effects of seasonality of photosynthesis, root activity and litterfall on RS, the observed decrease in its temperature sensitivity at low θ was consistent with the reduction in substrate availability due to a decrease in (a) microbial mobility, and diffusion of substrates and extracellular enzymes, and (b) the fraction of substrate that can react at high TS, which is associated with low θ. We found that an exponential (van't Hoff type) model with Q10 and R10 dependent on only θ explained 92% of the variance in half‐hourly values of RS, including the period with soil water stress conditions. We hypothesize that relating Q10 and R10 to θ not only accounted for the effects of TS on RS and its temperature sensitivity but also accounted for the seasonality of biotic (photosynthesis, root activity, and litterfall) and abiotic (soil moisture and temperature) controls and their interactions.
Perceptions about quality of life in a school‐based population of adolescents with menorrhagia: implications for adolescents with bleeding disorders
Authors: PAWAR A. , KRISHNAN R. , DAVIS K. , BOSMA K. , KULKARNI R.
Published: February 2008

Summary.  This study examined the effect of menorrhagia on the quality of life (QOL) of adolescents. We used data from a survey of 45 adolescents. Using the Pictorial Blood Assessment Chart (PBAC) and a PBAC score of ≥100 we identified adolescents likely to have menorrhagia. Our statistical analysis indicated that menorrhagia adversely affects the QOL of adolescents. In this article we discuss the implications of our study and future research avenues.
Physicians’ preferences towards coagulation factor concentrates in the treatment of Haemophilia with inhibitors: a discrete choice experiment
Authors: LEE WC , JOSHI A. V. , WOOLFORD S. , SUMNER M. , BROWN M. , HADKER N. , PASHOS C. L.
Published: February 2008

Summary.  This study sought to identify attributes of treatment important to haematologists in making their decisions regarding optimal care for inhibitor patients in the United States. A conjoint analysis using a discrete choice experiment was conducted to elicit factors that are most important to haematologists. Twelve product attributes were chosen based on published literature and expert opinion: risk of human viral infections, possibility that the titre of the inhibitor may rise, reduction in the likelihood of dose‐related thromboembolic events, the number of infusions required to stop haemorrhage, infusion preparation time, infusion time, infusion volume, time required to stop bleeding, time required to alleviate pain, prophylaxis use, ability to undergo major surgery and cost of medications. Thirty haematologists completed the questionnaires via face‐to‐face interviews at a scientific meeting in April 2006. Data were analysed using a multinomial logit model to obtain the relative importance of each attribute. Responding haematologists had considerable experience in treating haemophilia patients with inhibitors (average : 13 ± 9  years). ‘Time required to stop bleeding’ was the most important factor affecting treatment decisions [relative importance (RI) = 16.3%]. Physicians also preferred treatments that resulted in quick pain relief [RI = 12.9%], reduced the possibility that the titre of inhibitor may rise [RI = 12.8%], required fewer number of infusions to stop a haemorrhage [RI = 12.7%] and reduced the risk of human viral infection [RI = 10.8%]. This study revealed that certain clinical outcomes attributes are the most preferred and important. These findings can assist decision makers in their assessments of optimal first‐line care.
Multiple invasions of Errantivirus in the genus Drosophila
Authors: Ludwig A. , Valente V. L. da S. , Loreto E. L. S.
Published: February 2008

Aiming to contribute to the knowledge of the evolutionary history of Errantivirus, a phylogenetic analysis of the env gene sequences of Errantivirus gypsy, gtwin, gypsy2, gypsy3, gypsy4 and gypsy6 was carried out in 33 Drosophilidae species. Most sequences were obtained from in silico searches in the Drosophila genomes. The complex evolutionary pattern reported by other authors for the gypsy retroelement was also observed in the present study, including vertical transmission, ancestral polymorphism, stochastic loss and horizontal transfer. Moreover, the elements gypsy2, gypsy3, gypsy4 and gypsy6 were shown to have followed an evolutionary model that is similar to gypsy. Fifteen new possible cases of horizontal transfer were suggested. The infectious potential of these elements may help elucidate the evolutionary scenario described in the present study.
Extraction of policosanols from hydrolysed rice bran wax by high‐intensity ultrasound
Authors: Liu Yuanfa , Yu Jun , Wang Xingguo
Published: February 2008

This study provided a detailed method for extraction and purification of policosanols from hydrolysed rice bran wax (RBW) by high‐intensity ultrasound (HIU), where the hydrolysis of RBW under HIU was focused. The optimised operating conditions for hydrolysis were as the following: 20 kHz, 100 W, 1:2 of wax to 4% sodium hydroxide (w:v) and 50 min at ambient temperature, under which the hydrolysis rate of 94.3% was obtained. Thereafter, policosanols were extracted and purified from the hydrolysed RBW. With the analysis by GC, it was shown that even‐numbered aliphatic alcohols were the major components of the policosanols, accounting for 95% or so, where triacontanol (C30) was the predominant component with 26.95%, followed by octacosanol (C28) with 17.04%, dotriacotanol (C32) with 16.01%, tetracosanol (C24) with 11.13%, hexacosanol with 10.90%; however, the odd‐numbered alcohols only accounted for about 5% and they were non‐acosanol (C29) with 2.92%, heptacosanol (C27) with 1.57% and pentacosanol (C25) with 0.65%.
A mathematical model to describe the change in moisture distribution in maize starch during hydrothermal treatment
Authors: Zarguili Ikbal , Maache‐Rezzoug Zoulikha , Loisel Catherine , Doublier Jean‐Louis
Published: February 2008

Instantaneous Controlled Pressure Drop, ‘Détente Instantanée Contrôlée’ (DIC) was performed on standard maize starch at residual moisture content (∼12%). Changes in moisture distribution were observed during the treatment and modelled through a phenomenological model based on gravimetric data. The model proposes an exponential variation in the moisture content with processing time at various pressures. The predicted data were found to be in good agreement with experimental data. The values of water activity coefficient (γ) obtained from the model decrease, when processing pressure increases; 5.86, 3.71 and 3.36 (dry basis)−1 for 1, 2 and 3 bar, respectively. The mass transfer coefficient decreases, when the pressure increases. Its value ranged from 5.89 × 10−5 m s−1 for 1 bar down to 0.92 × 10−5 m s−1 for 2 bar and 0.77 × 10−5 m s−1 for 3 bar. This coefficient is not only controlled by a simple resistance to the mass transfer, but also by gelatinisation phenomenon that progresses when temperature increases.
Hazard analysis critical control points implementation in traditional foods: a case study of Tarhana processing
Authors: Dalgıç Ali C. , Belibağlı Kadir B.
Published: February 2008

This paper examines the factors, which influence the safety characteristics of Tarhana (Tarhana is a fermented, dried dough product commonly reconstituted and served as a hot soup). Since Tarhana is becoming an important part of the modern diet in many communities. The objectives of this study were to determine food safety practices and procedures related to the hazard analysis critical control point programme. The significant hazards found in hazard analysis were used for determination of risk assessment by five‐class hazard score matrix. The study revealed that the Critical Control Points (CCPs) for Tarhana production were cooking, fermentation, drying and sieving. At the same time, critical factors and limits for CCPs were determined. Preventative and corrective actions were proposed.
Consumer attitude and behaviour towards tomatoes after 10 years of Flandria quality labelling
Authors: Verbeke Wim , Velde Liesbeth Van de , Mondelaers Koen , Kühne Bianka , Huylenbroeck Guido Van
Published: February 2008

In recent years, trust in food safety and food quality has decreased as a result of consecutive food crises. Consequently, numerous quality labels signalling process‐related credence characteristics have been established. One of these labels is the Belgian Flandria quality label for fresh fruit and vegetables. Based on cross‐sectional data collected through a self‐administered consumer survey (n = 373), this paper addresses consumer attitudes, behaviour and perception towards tomatoes in general, and the Flandria tomato label in particular. Buyers, who constitute 26.8% of the sample, perceive Flandria tomatoes as superior to other tomatoes because of their guarantee of origin, better taste and stricter production control. However, they also report the strongest perception of Flandria as an ordinary tomato as compared to non‐buyer segments. Overall, findings indicate that the Flandria label – after being intensively used for 10 years for a wide range of other fruits and vegetables besides tomatoes – has become fairly standard for tomatoes with little perceived differentiation apart from its certified production and origin.
Osmotic dehydration kinetics of carrot cubes in sodium chloride solution
Authors: Singh Bahadur , Panesar Parmjit S. , Nanda Vikas
Published: February 2008

Osmotic dehydration kinetics of carrot cubes in sodium chloride solution having concentrations 5%, 10% and 15% (w/v), solution temperature 35, 45 and 55 °C, sample to solution ratio (STSR) 1:4, 1:5 and 1:6 were studied up to 240 min duration. During the experimentation, effect of solution temperature and process duration was significant and that of solution concentration and STSR were non‐significant on water loss. Among the different models applied (Penetration model, Magee Model, and Azuara model), Azuara model best fitted to the experimental data for water loss and solute gain during osmotic dehydration. Effective diffusivities of water and solute were calculated by using the analytical solution of Fick’s unsteady state law of diffusion by iterative technique with a computer program. For the above conditions, the effective diffusivity of water was found to be in the range between 2.6323 × 10−9 and 6.2397 × 10−9 m2/s and that of solute between 3.1522 × 10−9 and 4.6400 × 10−9 m2/s.
Fire and ice: genetic structure of the Uinta ground squirrel (Spermophilus armatus) across the Yellowstone hotspot
Authors: VAN TUINEN MARCEL , O’KEEFE KIM , RAMAKRISHNAN UMA , HADLY ELIZABETH A.
Published: February 2008

The range of the Uinta ground squirrel, Spermophilus armatus, is centred over one of the most tectonically active regions today, the Yellowstone hotspot. We document the role of Quaternary tectonic and climatic history on the genetic structure of this species by screening museum and extant individuals throughout its range. Phylogeographic, divergence time, and demographic analyses of partial mitochondrial cytochrome b and control region DNA sequences yield insight into the cadence of evolution across three spatiotemporal scales: (i) a relatively deep intraspecific divergence of S. armatus into three lineages coincident with the last major volcanic eruption in the region and maintained by the Snake River Plain; (ii) demographic expansion in two lineages corresponding to the time of last deglaciation of the region; and (iii) a recent (< 50 years) local extinction of the third lineage coincident with climatic change and conversion of habitat for agricultural purposes in eastern Idaho. Beyond these inferences, our study highlights the unique value of museum material to phylogeography, and shows that small mammal recolonization of previously glaciated montane ‘islands’ differs from northward postglacial expansion observed in areas previously covered by continental ice sheets. Montane ‘islands’ may harbour high genetic diversity because of admixture and recurrent expansion/extinction.
Escherichia coliDps interacts with DnaA protein to impede initiation: a model of adaptive mutation
Authors: Chodavarapu Sundari , Gomez Ruben , Vicente Matias , Kaguni Jon M.
Published: February 2008

During exponential growth, the level of Dps transiently increases in response to oxidative stress to sequester and oxidize Fe2+, which would otherwise lead to hydroxyl radicals that damage the bacterial chromosome. We report that Dps specifically interacts with DnaA protein by affinity chromatography and a solid phase binding assay, requiring the N‐terminal region of DnaA to interact.In vitro, Dps inhibits DnaA function in initiation by interfering with strand opening of the replication origin. Comparing isogenicdps+anddps::kanstrains by flow cytometry and by quantitative polymerase chain reaction assays at either the chromosomally encoded level, or at an elevated level encoded by an inducible plasmid, we show that Dps causes less frequent initiations. Results from genetic experiments support this conclusion. We suggest that Dps acts as a checkpoint during oxidative stress to reduce initiations, providing an opportunity for mechanisms to repair oxidative DNA damage. Because Dps does not block initiations absolutely, duplication of the damaged DNA is expected to increase the genetic variation of a population, and the probability that genetic adaptation leads to survival under conditions of oxidative stress.
SpvC is a Salmonella effector with phosphothreonine lyase activity on host mitogen‐activated protein kinases
Authors: Mazurkiewicz Piotr , Thomas Jerry , Thompson Jessica A. , Liu Mei , Arbibe Laurence , Sansonetti Philippe , Holden David W.
Published: February 2008

SpvC is encoded by the Salmonella virulence plasmid. We have investigated the biochemical function of SpvC and the mechanism by which it is secreted by bacteria and translocated into infected macrophages. We constructed a strain carrying a deletion in spvC and showed that the strain is attenuated for systemic virulence in mice. SpvC can be secreted in vitro by either the SPI‐1 or SPI‐2 type III secretion systems. Cell biological and genetic experiments showed that translocation of the protein into the cytosol of macrophages by intracellular bacteria is dependent on the SPI‐2 T3SS. Using antibodies specific to phospho‐amino acids and mass spectrometry we demonstrate that SpvC has phosphothreonine lyase activity on full‐length phospho‐Erk (pErk) and a synthetic 13‐amino‐acid phospho‐peptide containing the TXY motif. A Salmonella strain expressing spvC from a plasmid downregulated cytokine release from infected cells.
The heat‐shock protein ClpB of Francisella tularensis is involved in stress tolerance and is required for multiplication in target organs of infected mice
Authors: Meibom Karin L. , Dubail Iharilalao , Dupuis Marion , Barel Monique , Lenco Juraj , Stulik Jiri , Golovliov Igor , Sjöstedt Anders , Charbit Alain
Published: February 2008

Intracellular bacterial pathogens generally express chaperones such as Hsp100s during multiplication in host cells, allowing them to survive potentially hostile conditions. Francisella tularensis is a highly infectious bacterium causing the zoonotic disease tularaemia. The ability of F. tularensis to multiply and survive in macrophages is considered essential for its virulence. Although previous mutant screens in Francisella have identified the Hsp100 chaperone ClpB as important for intracellular survival, no detailed study has been performed. We demonstrate here that ClpB of F. tularensis live vaccine strain (LVS) is important for resistance to cellular stress. Promoter analysis shows that the transcriptional start is preceded by a σ32‐like promoter sequence and we demonstrate that expression of clpB is induced by heat shock. This indicates that expression of clpB is dependent on the heat‐shock response mediated by σ32, the only alternative σ‐factor present in Francisella. Our studies demonstrate that ClpB contributes to intracellular multiplication in vitro, but is not essential. However, ClpB is absolutely required for Francisella to replicate in target organs and induce disease in mice. Proteomic analysis of membrane‐enriched fractions shows that five proteins are recovered at lower levels in the mutant strain. The crucial role of ClpB for in vivo persistence of Francisella may be linked to its assumed function in reactivation of aggregated proteins under in vivo stress conditions.
Biopsy‐proven adenoviral diarrhea responding to low‐dose cidofovir
Authors: Nicolasora N.P. , Reddy P. , Kaul D.R.
Published: February 2008

Abstract: We present a case of diarrhea secondary to biopsy‐proven adenovirus (ADV) infection after autologous peripheral hematopoietic stem cell transplant for multiple myeloma. The patient had a negative plasma polymerase chain reaction for ADV and a dramatic clinical response to low‐dose cidofovir. To our knowledge, this is the first report in an adult hematopoietic stem cell recipient of the use of low‐dose cidofovir to treat proven ADV gastrointestinal infection.
DISTINCT ROLE OF ADRENOCEPTOR SUBTYPES IN CARDIAC ADAPTATION TO CHRONIC PRESSURE OVERLOAD
Authors: Du Xiao‐Jun
Published: February 2008

With the generation of gene knockout (KO) or transgenic overexpression (TG) mouse models targeting adrenoceptors (AR), recent studiesin vivohave investigated the role of AR subtypes in pressure overload‐induced left ventricular (LV) hypertrophy and remodelling.

Although subjecting α1B‐KO mice to transverse aortic constriction (TAC) did not reveal significant phenotype differences compared with controls, mice deficient in both α1A‐ and α1B‐AR responded to TAC with poor survival, increased cardiomyocyte apoptosis, more severe fibrosis and dysfunction, but a similar degree of LV hypertrophy, compared with wild‐type littermates. Following TAC, α1B‐TG mice developed more severe hypertrophy, interstitial fibrosis and LV dysfunction. In contrast, overexpression of α1A‐AR preserved cardiac function and reduced death from heart failure without affecting the degree of LV hypertrophy. Thus, α1A‐ and α1B‐adrenoceptor signalling impacts differently on myocardial adaptation to pressure overload.

The absence of both β1‐ and β2‐AR significantly suppressed pressure overload‐evoked hypertrophy, fibrosis and expression of inflammatory or fibrogenic genes. Conversely, studies on β2‐TG mice with TAC revealed adverse consequences, including accelerated development of heart failure, poor survival and more severe interstitial fibrosis, but a comparable degree of hypertrophy compared with wild‐type littermates.

Collectively, these findings suggest that the effect of ARs on pressure overload‐induced myocardial adaptation is subtype specific. Whereas activation of α1B‐AR or β2‐AR contributes to maladaptation and the onset of heart failure, activation of α1A‐AR or inactivation of β2‐AR is beneficial in the setting of chronic pressure overload.
ROLE OF INSULIN‐LIKE GROWTH FACTOR 1 AND PHOSPHOINOSITIDE 3‐KINASE IN A SETTING OF HEART DISEASE
Authors: McMullen Julie R
Published: February 2008

The insulin‐like growth factor 1 (IGF1)–phosphoinositide 3‐kinase (PI3‐K) pathway is a critical regulator of cell and organ growth.

In the heart, the IGF1–PI3‐K pathway induces physiological heart growth with preserved or enhanced cardiac function.

The present review specifically discusses the role of the IGF1–PI3‐K pathway in the setting of heart disease.

Genetic mouse models have highlighted the beneficial effects of the IGF1–PI3‐K pathway in the heart in a setting of disease. These include maintenance of contractile function, antifibrotic and anti‐apoptotic actions, inhibition of signalling transducers activated in disease settings and regeneration.
UNDERSTANDING THE ROLE OF TRANSFORMING GROWTH FACTOR‐β SIGNALLING IN THE HEART: OVERVIEW OF STUDIES USING GENETIC MOUSE MODELS
Authors: Xiao Han , Zhang You‐Yi
Published: February 2008

In the present review, we focus on the genetic mouse models for transforming growth factor (TGF)‐β signalling, which have aided our understanding on the role of the TGF‐β signalling pathway in cardiac hypertrophy/fibrosis and the molecular mechanisms involved.

Knockout of TGF‐β is embryonic lethal, indicating that TGF‐β signalling plays an important role in embryonic development. In order to avoid this defect, many mouse strains with cardiac‐specific targeted genes in TGF‐β signalling have been developed.

The TGF‐β family signalling pathway includes Smad‐dependent and ‐independent pathways.

Investigations using the genetic mouse models have confirmed and uncovered the involvement of the TGF‐β/TGF‐β‐activated kinase 1 (TAK1) pathway in the development of cardiac hypertrophy and fibrosis. Although the downstream cascade of TAK1‐induced cardiac hypertrophy remains only partially defined, recent research indicates that the TGF‐β/TAK1/p38 pathway is involved in cardiac fibrosis

Smad‐dependent signalling may not be involved in, or may even be inhibitory for, cardiac hypertrophy.
Eu‐Chlorella large subunit rDNA sequences and group I introns in ribosomal DNA of the paramecian symbiotic alga NC64A
Authors: Hoshina Ryo , Imamura Nobutaka
Published: February 2008

Although the examination of large subunit ribosomal RNA genes (LSU rDNA) is advanced in phylogenetic studies, no corresponding sequence data from trebouxiophytes have been published, with the exception of ‘Chlorella’ellipsoidea Gerneck. We determined the LSU rDNA sequence of Chlorella vulgaris Beijerinck and of the symbiotic alga of green paramecium, Chlorella sp. NC64A. A total of 59 nucleotide substitutions were found in the LSU rDNA of the two species, which are disproportionately distributed. Primarily, 65% of the substitutions were encountered in the first 800 bp of the alignment. This segment apparently has evolved eight times faster than the complete SSU rDNA sequence, making it a good candidate for a phylogenetic marker and giving a resolution level intermediate between small subunit (SSU) rDNA and internal transcribed spacers. Green algae are known as a group I intron‐rich group along with rhodophytes and fungi. NC64A is particularly rich in the introns; five introns were newly identified from the LSU rDNA sequence, which we named Cnc.L200, Cnc.L1688, Cnc.L1926, Cnc.L2184 and Cnc.L2437, following the insertion positions. In the present study we analyzed these introns with three others (Cnc.S943, Cnc.S1367 and Cnc.S1512) that had already been found in NC64A SSU rDNA. Secondary structure modeling placed these introns in the group I intron family, with four introns belonging to subgroup C1 and the other four introns belonging to subgroup E. Five of the intron insertion positions are unique to the paramecian symbiont, which may indicate relatively recent events of intron infections that includes transpositions. Intron phylogeny showed unprecedented relationships; four Cnc. IC1 introns made a clade with some green algal introns with insertions at nine different positions, whereas four Cnc. IE introns made a clade with the S651 intron (Chlorella sp. AN 1–3), which lay as a sister to the S516 insertion position subfamily.
Germination and survival of tetraspores of Kappaphycus alvarezii var. alvarezii (Solieriaceae, Rhodophyta) introduced in subtropical waters of Brazil
Authors: Bulboa Cristian , De Paula Edison J. , Chow Fungyi
Published: February 2008

The carrageenophyte Kappaphycus alvarezii was introduced in 1995 and vegetatively propagated in Ubatuba, São Paulo State, Brazil, for the purpose of commercial cultivation. This species produces tetraspores mainly in the austral summer and fall. Tetraspore germination and survival were studied under different conditions of temperature, photon flux density, and photoperiod in the laboratory. Field experiments were also carried out. Although tetraspores of K. alvarezii germinated, they had low survival rates, most dying after 20 days. Recruitment of K. alvarezii tetraspores did not occur in experiments conducted in the field. The results indicated that the establishment of K. alvarezii via spore production in the natural environment of the south‐east coast of Brazil is rather remote.
Complexation of iron by microbial siderophores and effects of iron chelates on the growth of marine microalgae causing red tides
Authors: Naito Kanako , Imai Ichiro , Nakahara Hiroyuki
Published: February 2008

The growth rates of 13 species of abundant red tide algae in media with different iron species complexed with microbial siderophores (Ferrichrome and Ferrioxamine) and Fe‐Catechol were investigated. Our study demonstrated that the Fe‐chelates (at molar ratios = 1:1) were bioavailable to some red tide species. In Fe‐Catechol medium, growth was observed for the raphidophyte Heterosigma akashiwo, the dinoflagellates Heterocapsa circularisquama and Heterocapsa triquetra, the diatom Ditylum brightwellii, the cryptophyte Rhodomonas ovalis, the chlorophyte Oltmannsiellopsis viridis, and the haptophyte Cricosphaera roscoffensis. In Ferrioxamine medium, we found the growth of the dinoflagellate Karenia mikimotoi, the diatom Ditylum brightwellii, and the cryptophyte Rhodomonas ovalis. But, the existence of higher ligand concentrations (molar ratios ≥ 1:10) decreased the growth rates of most red tide species that were examined. Furthermore, all red tide species examined were not able to grow in Ferrichrome medium. In particular, the Chattonella species examined did not grow in the presence of Fe‐chelates. These results suggest that bioavailability of iron depends not only on ligand species, but also on the concentration of the ligands; moreover, microbial siderophores may play an important role in controlling the uptake of iron complexed with organic materials that exist in coastal water and the formation of red tides in coastal areas.
Mycangia of the ambrosia beetle, Austroplatypus incompertus (Schedl) (Coleoptera: Curculionidae: Platypodinae)
Authors: Kent Deborah S
Published: February 2008

Abstract  Ambrosia beetles have an obligate relationship with the ambrosia fungi that they feed on. This requires that the beetles have means to transport those fungi when they colonise new hosts. Some ambrosia beetles have special structures called mycangia to transport fungi in. This paper describes the mycangia of the ambrosia beetle Austroplatypus incompertus and illustrates how the mycangical hairs are probably used by the beetle to acquire fungal spores for transport. The mycangia and probable method of fungal acquisition of this species are compared with those of other ambrosia beetles.
Advanced eusociality, kin selection and male haploidy
Authors: Crozier Ross H
Published: February 2008

Abstract The generation‐long primacy of kin selection in explaining the evolution of advanced eusociality in social insects has been challenged in recent papers. Does this challenge succeed? I consider three questions: is kin selection still the unchallengeable explanation for the evolution of eusociality; is the male haploidy of Hymenoptera important in this explanation; and, a subsidiary question of why are there no male workers in Hymenoptera? I briefly trace the origins of kin selection back to Darwin and then consider the explanations of mutualism, group selection, parental manipulation, and kin selection and its variant ‘green beard’ alleles. I stress that in the kin selection equation, however written, relatedness is deeply intertwined with ecology so that both are essential. Kin selection does remain unchallengeable but, for some, the role of male haploidy has lost favour recently despite several modelling efforts all finding that it favours the evolution of eusociality. Sex allocation is deep at the heart of the evolution of hymenopteran advanced eusociality, indicating the interacting roles of population genetics and general biology. Modellers have also found no reason for a lack of male workers, so that a biological superiority of females for this role is indicated for social Hymenoptera.
Seasonal trade‐off between starvation resistance and cold resistance in temperate wild‐caught Drosophila simulans
Authors: Kenny McCabe C , Wilton Alan , Ballard J William O
Published: February 2008

Abstract  Selection experiments with Drosophila have revealed a possible evolutionary trade‐off between cold resistance and starvation resistance that may be controlled by lipid metabolism. To test this trade‐off in naturally occurring Drosophila simulans populations, flies were simultaneously collected from two temperate locales experiencing contrasting seasons. Flies from a tropical locale served as a control. Cold coma recovery, starvation resistance and lipid proportion were assayed on adult males and females from each locale. Compared with the summer‐collected flies from Canberra, the winter‐collected flies from San Diego recovered from cold coma more quickly, were less starvation resistant and had lower lipid levels. These results support an evolutionary trade‐off between cold resistance and starvation resistance. Combined, these data also suggest that differences in lipid metabolism may be an underlying mechanism for this trade‐off.
Field evaluation of spinosad as a grain protectant for stored wheat in Australia: efficacy against Rhyzopertha dominica (F.) and fate of residues in whole wheat and milling fractions
Authors: Daglish Gregory J , Head Matthew B , Hughes Paul B
Published: February 2008

Abstract  The potential of spinosad as a grain protectant for the lesser grain borer, Rhyzopertha dominica, was investigated in a silo‐scale trial on wheat stored in Victoria, Australia. Rhyzopertha dominica is a serious pest of stored grain, and its resistance to protectants and the fumigant phosphine is becoming more common. This trial follows earlier laboratory research showing that spinosad may be a useful pest management option for this species. Wheat (300 t) from the 2005 harvest was treated with spinosad 0.96 mg/kg plus chlorpyrifos‐methyl 10 mg/kg in March 2006, and samples were collected at intervals during 7.5 month storage to determine efficacy and residues in wheat and milling fractions. Chlorpyrifos‐methyl is already registered in Australia for control of several other pest species, and its low potency against R. dominica was confirmed in laboratory‐treated wheat. Grain moisture content was stable at about 10%, but grain temperature ranged from 29.3°C in March to 14.0°C in August. Bioassays of all treated wheat samples over 7.5 months resulted in 100% adult mortality after 2 weeks exposure and no live progeny were produced. In addition, no live grain insects were detected during outload sampling after a 9 month storage. Spinosad and chlorpyrifos‐methyl residues tended to decline during storage, and residues were higher in the bran layer than in either wholemeal or white flour. This field trial confirmed that spinosad was effective as a grain protectant targeting R. dominica.
Retrobulbar blood flow and ophthalmic perfusion in maximum dynamic exercise
Authors: Kozobolis Vassilios P , Detorakis Efstathios T , Konstas Anastasios G , Achtaropoulos Athanassios K , Diamandides Evangelos D
Published: February 2008

Abstract

Purpose:  To study the effects of maximum dynamic physical exercise on retrobulbar blood flow and ocular perfusion pressure (OPP).

Methods:  Thirty male subjects undergoing routine periodic medical evaluation were included. All participants underwent cardiac stress test according to a standard protocol. Before the test, the intraocular pressure was measured and colour Doppler imaging was performed with a 7.5 MHz linear probe, to record peak systolic velocity (PSV), end diastolic velocity and resistivity index at the ophthalmic artery (OA), central retinal artery (CRA) and nasal and temporal branches of short posterior ciliary arteries (SPCA). The same measurements were repeated 1 and 30 min after the test.

Results:  OPP and PSV at the OA were significantly higher at the 1‐min interval, compared with the pretest scores (P = 0.01, in both cases), whereas the respective differences on the 30‐min interval were statistically not significant. On the contrary, PSV at the CRA and SPCA were not significantly changed on the same intervals. Differences between pretest and post‐test scores for end diastolic velocity and resistivity index were statistically not significant for all examined vessels.

Conclusions:  Maximal physical exercise increases OPP and blood flow at the OA without affecting blood flow at the CRA and SPCA, implying that auto‐regulative mechanisms are active in both retinal and choroidal circulations.
Huntington disease in indigenous Australians
Authors: Panegyres P. K. , McGrath F.
Published: February 2008

Huntington disease (HD) in indigenous Australians is a poorly analysed and difficult problem. This study addresses the issue of HD in remote indigenous Australian populations in the north‐west of Western Australia. Proband identification, clinical assessment, neurogenetic studies and pedigree analysis led to the discovery of HD in the 63‐year‐old male proband and his family. HD in remote indigenous Australian communities is a challenging diagnostic and management problem compounded by the complexity of distance.
Guidelines for the prevention of sepsis in asplenic and hyposplenic patients
Authors: Spelman D. , Buttery J , Daley A. , Isaacs D. , Jennens I. , Kakakios A. , Lawrence R. , Roberts S. , Torda A. , Watson D. A. R. , Woolley I. , Anderson T. , Street A.
Published: February 2008

Asplenic or hyposplenic patients are at risk of fulminant sepsis. This entity has a mortality of up to 50%. The spectrum of causative organisms is evolving as are recommended preventive strategies, which include education, prophylactic and standby antibiotics, preventive immunizations, optimal antimalarial advice when visiting endemic countries and early management of animal bites. However, there is evidence that adherence to these strategies is poor. Consensus‐updated guidelines have been developed to help Australian and New Zealand clinicians and patients in the prevention of sepsis in asplenic and hyposplenic patients.
Continuous positive airway pressure in heart failure patients with obstructive sleep apnoea
Authors: Ferrier K. A. , Neill A. M. , O’Meeghan T. , Richards M. , Campbell A. J.
Published: February 2008

Background:  The aim of the study was to study the effect of 6 months of continuous positive airway pressure (CPAP) in community heart failure (HF) patients with obstructive sleep apnoea (OSA).

Methods:  Clinically stable outpatients with HF and OSA (left ventricular ejection fraction (LVEF) <45%, apnoea/hypopnoea index >15/h, n = 19) treated with CPAP and a control group (LVEF <45%, apnoea/hypopnoea index <10/h, n = 7) were compared at baseline and at 6 months by Minnesota heart failure score, Epworth sleepiness score, shuttle walk distance, brain natriuretic peptide, urinary catecholamines and echocardiographic indices using paired t‐test, McNemar’s tests and effect sizes.

Results:  In HF patients with OSA, CPAP improved LVEF (35.9 ± 6.1% to 40.6 ± 8.0%, P = 0.015), decreased LV end‐systolic volume (152 ± 74 to 135 ± 62 cm3, P = 0.03), systolic blood pressure (P = 0.04) and sleepiness (Epworth sleepiness score 8.8 ± 4.8 to 6.3 ± 3.2, P = 0.01), whereas walk distance, catecholamines, brain natriuretic peptide levels and symptoms were unchanged. These outcomes did not change in the HF control group.

Conclusion:  In community HF patients with OSA, CPAP therapy over 6 months improved LVEF, systolic blood pressure and sleepiness, but not sympathetic activation, brain natriuretic peptide or exercise levels. Acceptance was relatively low, potentially limiting therapeutic effectiveness.
Is there any role for computed tomography measurements of medial temporal lobe atrophy in dementia? A review of the literature and case series from a memory clinic
Authors: Rose M. , Scharf S.
Published: February 2008

Neuroimaging in dementia has focused on documenting any burden of vascular disease or excluding any reversible intracranial pathology. We review the use of computed tomography to examine for medial temporal lobe atrophy in dementia and compare this with a case series of such measurements from our memory clinic. Measures of medial temporal lobe atrophy were used to separate patients with Alzheimer’s disease from those with normal cognition, mood disorders or other forms of early dementia.
Management of distal ulcerative colitis: frequently asked questions analysis
Authors: James S. L. , Irving P. M. , Gearry R. B. , Gibson P. R.
Published: February 2008

The majority of patients with ulcerative colitis have disease involving only the distal colon. Although 5‐aminosalicylic acid (5‐ASA, mesalazine) and corticosteroids remain the important drugs used in the management of distal colitis and proctitis, recent expansion of delivery options of 5‐ASA and high level evidence regarding efficacy have led to a shift in treatment strategies. The availability of 5‐ASA in enema, foam and suppository formulations has enabled optimization of delivery of 5‐ASA to the affected mucosa. Such therapy has superior efficacy and fewer adverse effects compared with those of topical corticosteroids. Furthermore, rectal delivery is effective in the maintenance of remission. Consequently, new guidelines for the management of distal colitis have focussed more on rectal delivery and on optimizing 5‐ASA dosage than previously. However, corticosteroids remain an important remission‐inducing agent, and immune‐modulating drugs play a clear role in prevention of relapse and in managing chronically active disease. The changes in guidelines have raised several management questions, many of which are addressed in this review.
Type 1 fimbriae of insecticidal bacterium Xenorhabdus nematophila is necessary for growth and colonization of its symbiotic host nematode Steinernema carpocapsiae
Authors: Chandra Harish , Khandelwal Puneet , Khattri Arun , Banerjee Nirupama
Published: February 2008

Xenorhabdus nematophila produces type 1 fimbriae on the surface of Phase I cells. Fimbriae mediate recognition and adhesion of the bacteria to its target cell. To investigate the role of fimbriae in the biology of X. nematophila, we have produced a fimbrial mutant strain by insertional inactivation of the mrxA gene, encoding the structural subunit of type 1 fimbriae. Phenotypic characterization of the mutant revealed loss of fimbriae on the cell surface. Cell surface characteristics like dye absorption, biofilm formation, red blood cell agglutination remained unaltered. The mrxA mutant was defective in swarming on soft agar, although swimming motility was not affected. Flagellar expression was suppressed in the mrxA strain under swarming conditions, but not swimming conditions. Agglutination and cytotoxicity of the mutant to larval haemocytes was also reduced. When the mutant cells were injected in the haemocoel of the fourth instar larvae of Helicoverpa armigera, an increase in the LT50 of 9–12 h was observed relative to the wild‐type strain. The nematode growth was slow on the lawn of the fimbrial mutant. The mrxA negative strain was unable to colonize the nematode gut efficiently. This study demonstrates importance of type 1 fimbriae in establishment of bacteria‐nematode symbiosis, a key to successful pest management program.