bluuebunny/crossref_metadata_2025 huggingface dataset:
Diagnosing acute lung injury in the critically ill: a national survey among critical care physicians
Authors: VLAAR A. P. J. , HONSELAAR W. B. , BINNEKADE J. M. , GROENEVELD A. B. , SPRONK P. E. , SCHULTZ M. J. , JUFFERMANS N. P.
Published: August 2009

Background: Incidence reports on acute lung injury (ALI) vary widely. An insight into the diagnostic preferences of critical care physicians when diagnosing ALI may improve identification of the ALI patient population.

Methods: Critical care physicians in the Netherlands were surveyed using vignettes involving hypothetical patients and a questionnaire. The vignettes varied in seven diagnostic determinants based on the North American European Consensus Conference and the lung injury score. Preferences were analyzed using a mixed‐effects logistic regression model and presented as an odds ratio (OR) with a 95% confidence interval.

Results: From 243 surveys sent to 30 hospitals, 101 were returned (42%). ORs were as follows: chest X‐ray consistent with ALI: OR 1.7 (1.3–2.3), high positive end‐expiratory pressure (PEEP) (15 cmH2O): OR 5.0 (3.9–6.6), low pulmonary artery occlusion pressures (PAOP) (<18 mmHg): OR 4.7 (3.6–6.1), low compliance (30 ml/cmH2O): OR 0.7 (0.5–0.9), low PaO2/FiO2 (<250 mmHg): OR 9.2 (6.9–12.3), absence of heart failure: OR 1.2 (0.9–1.5), presence of a risk factor for ALI (sepsis): OR 1.0 (0.8–1.3). The questionnaire revealed that critical care physicians with an anesthesiology background differed from physicians with an internal medicine background with regard to hemodynamic variables when considering an ALI diagnosis (P<0.05).

Conclusions: Dutch critical care physicians consider the PEEP level, but not the presence of a risk factor for ALI, as an important factor to diagnose ALI. Background specialty of critical care physicians influences diagnostic preferences and may account for variance in the reported incidence of ALI.
Electrical impedence tomography and heterogeneity of pulmonary perfusion and ventilation in porcine acute lung injury
Authors: FAGERBERG A. , SÖNDERGAARD S. , KARASON S. , ÅNEMAN A.
Published: August 2009

Background: The heterogeneity of pulmonary ventilation (V), perfusion (Q) and V/Q matching impairs gas exchange in an acute lung injury (ALI). This study investigated the feasibility of electrical impedance tomography (EIT) to assess the V/Q distribution and matching during an endotoxinaemic ALI in pigs.

Methods: Mechanically ventilated, anaesthetised pigs (n=11, weight 30–36 kg) were studied during an infusion of endotoxin for 150 min. Impedance changes related to ventilation (ZV) and perfusion (ZQ) were monitored globally and bilaterally in four regions of interest (ROIs) of the EIT image. The distribution and ratio of ZV and ZQ were assessed. The alveolar–arterial oxygen difference, venous admixture, fractional alveolar dead space and functional residual capacity (FRC) were recorded, together with global and regional lung compliances and haemodynamic parameters. Values are mean±standard deviation (SD) and regression coefficients.

Results: Endotoxinaemia increased the heterogeneity of ZQ but not ZV. Lung compliance progressively decreased with a ventral redistribution of ZV. A concomitant dorsal redistribution of ZQ resulted in mismatch of global (from ZV/ZQ 1.1±0.1 to 0.83±0.3) and notably dorsal (from ZV/ZQ 0.86±0.4 to 0.51±0.3) V and Q. Changes in global ZV/ZQ correlated with changes in the alveolar–arterial oxygen difference (r2=0.65, P<0.05), venous admixture (r2=0.66, P<0.05) and fractional alveolar dead space (r2=0.61, P<0.05). Decreased end‐expiratory ZV correlated with decreased FRC (r2=0.74, P<0.05).

Conclusions: EIT can be used to assess the heterogeneity of regional pulmonary ventilation and perfusion and V/Q matching during endotoxinaemic ALI, identifying pivotal pathophysiological changes.
Impact of theCYP2D6genotype on post‐operative intravenous oxycodone analgesia
Authors: ZWISLER S. T. , ENGGAARD T. P. , MIKKELSEN S. , BROSEN K. , SINDRUP S. H.
Published: August 2009

Background:Oxycodone is a semi‐synthetic opioid with a μ‐receptor agonist‐mediated effect in several pain conditions, including post‐operative pain. Oxycodone is metabolized to its active metabolite oxymorphone byO‐demethylation via the polymorphic CYP2D6. The aim of this study was to investigate whether CYP2D6 poor metabolizers (PMs) yield the same analgesia post‐operatively from intravenous oxycodone as extensive metabolizers (EMs).

Methods:Two hundred and seventy patients undergoing primarily thyroid surgery or hysterectomy were included and followed for 24 h post‐operatively. TheCYP2D6genotype was blinded until study procedures had been completed for all patients. All patients received intravenous oxycodone as pain treatment for 24 h post‐operatively and morphine 5 mg was used as escape medication. A responder was characterized as a patient without the need for escape medication and a positive evaluation in a questionnaire 24 h post‐operatively.

Results:Twenty‐four patients were PM (8.9%) and 246 were EM (91.1%). One PM (4.17%, CI=0.1–21.1) was a non‐responder and 42 EM (17.07%, CI=12.6–22.4) were non‐responders. The non‐responder rate did not differ between the two genotypes (P=0.14). There was no difference in the total consumption of oxycodone between the two genotypes (EM=14.7 mg, CI=13.0–16.4 and PM=13.0 mg, CI=8.9–17.0,P=0.42). The mean oxymorphone/oxycodone ratios were 0.0031 and 0.00081 in the EMs and PMs, respectively (P<0.0001).

Conclusion:This study showed for the first time in patients that the oxymorphone formation depends on CYP2D6, but we found no difference in the post‐operative analgesic effect of intravenous oxycodone between the twoCYP2D6genotypes.
Spread of spinal block in patients with rheumatoid arthritis
Authors: LEINO K. A. , KUUSNIEMI K. S. , PÄLVE H. K. , KORPELAINEN J. T. , TIUSANEN H. T. , TUPPURAINEN T. T.
Published: August 2009

Background: In clinical practice, we noticed a greater than expected spread of sensory spinal block in patients with rheumatoid arthritis. We decided to test this impression and compared the spread of standard spinal anaesthesia in rheumatoid and non‐rheumatoid control patients.

Methods: Spinal anaesthesia with 3.4 ml (17 mg) of plain bupivacaine was administered to 50 patients with seropositive rheumatioid arthritis and to 50 non‐rheumatoid control patients. The protocol was standardised for all patients. All the patients were undergoing lower limb surgery and the rheumatoid patients were operated on due to their rheumatoid disease. The spread of sensory block was recorded 30 min from the dural puncture using a pin prick test and a cold ice‐filled container. The impact of body mass index (BMI), height and age on the spread were analysed.

Results: The spread of sensory block was greater in patients with rheumatoid arthritis (15.6±3.1 dermatomes) than in non‐rheumatoid patients (14.1±3.3 dermatomes) (P<0.05). Increasing BMI was related to cephalad spread of block in the rheumatoid group (P<0.05), but not in the control group.

Conclusion: The mean spread of sensory block 30 min after the injection of plain bupivacaine was 1.5 segments cephalad in patients with rheumatoid arthritis than in those without this disease. BMI might be a patient‐related factor contributing to the extent of the block in rheumatoid patients. These findings should be considered when performing a spinal block in rheumatoid patients.
Mycological and histological investigations of Fraxinus excelsior nursery saplings naturally infected by Chalara fraxinea
Authors: Schumacher J. , Kehr R. , Leonhard S.
Published: September 2009

Ash dieback is an emerging disease of Fraxinus excelsior in Germany. To date, economical damage is significant in nurseries, which also contribute towards spread of the disease, but damage to forests is increasing. The study presents the results of mycological and histological investigations on three hundred 3‐year‐old nursery ash saplings. The infection rate by the causative pathogen was determined for bark, outer and inner xylem, the pith and also separately for the above‐ground portion and root system of the plants. The invasion and colonization strategy of the fungus in the woody stem was examined. In addition, the presence of soil‐borne Oomycetes as possible primary or accompanying causal organisms was investigated. The results verify the dominant role of Chalara fraxinea as a causal agent of ash dieback and rule out the role of Oomycetes in the disease process. We conclude that C. fraxinea is not primarily endophytic in nature and spreads very effectively in the central stem tissues, which enables colonization of the woody stem in all three dimensions. Infections arising in the upper part of plants can thus spread extensively to lower parts.
Starch Content and Granule Size Distribution in Grains of Wheat in Relation to Post‐Anthesis Water Deficits
Authors: Zhang T. , Wang Z. , Yin Y. , Cai R. , Yan S. , Li W.
Published: August 2009

Post‐anthesis soil moisture condition is closely associated with grain yield and quality in wheat (Triticum aestivum L.). To investigate the effect of post‐anthesis water deficit (WD) on starch content and granule size distribution, pot‐experiments were conducted in 2006–2007 and 2007–2008 growing seasons, using five wheat cultivars with different amylose content. The result showed that the grain starch granules had a bimodal curve in the volume and surface area distribution, and a unimodal curve was found in number distribution. Post‐anthesis WD reduced the B‐granules (<10 μm in diameter) volume % and surface area % in Nuomai50206 and Gaocheng8901, increased the proportion in Weimai10, whereas the effect on those in Jinan17 and Shannong15 was not significant. Post‐anthesis WD decreased the number % of <2 μm starch granules, significantly in all cultivars. The amylose content was negatively correlated with the volume of <10 μm and positively correlated to >15 μm starch granules, respectively, suggesting that small starch granules (<10 μm) are low in amylose content, whereas, big starch granules (>15 μm) are high. The results indicate that the grain starch granule size distributions of Jinan17 and Shannong15 with high amylose content were less affected by WD, than those of Nuomai50206 and Gaocheng8901 with low amylose content.
Different Patterns of Physiological and Molecular Response to Drought in Seedlings of Malt‐ and Feed‐type Barleys (Hordeum vulgare)
Authors: Rapacz M. , Kościelniak J. , Jurczyk B. , Adamska A. , Wójcik M.
Published: August 2009

A number of physiological and molecular characteristics are proposed as selection criteria for drought tolerance. This study measured the associations between physiological and molecular characteristics of drought response in malting and fodder spring barleys. Plants of 13 malt‐ and 14 feed‐type Polish genotypes were exposed to drought at the four‐leaf stage for 7 days. Drought susceptibility indexes (DSI) were calculated for membrane integrity, water status, gas exchange and PSII photochemical activity. Accumulation of HVA1 and SRG6 transcripts in drought was measured with real‐time PCR. A wide range of variation in the drought response was observed among studied genotypes. Malting barleys were less sensitive to drought than feed‐barleys according to all the traits studied. In both groups, different patterns of relationships between traits were observed. In malting genotypes only, CO2 assimilation rates in drought, as well as PSII efficiency were related to both water content and the accumulation of HVA1 transcript in leaves. On the other hand the SRG6 expression was highly correlated in both groups of barley with the photochemical efficiency of PSII. The results suggest that different physiological, biochemical and molecular characteristics should be applied in the selection towards drought resistance in the case of malting and fodder barleys.
Heat Shock Protein in Developing Grains in Relation to Thermotolerance for Grain Growth in Wheat
Authors: Sharma‐Natu P. , Sumesh K. V. , Ghildiyal M. C.
Published: August 2009

Wheat (Triticum aestivum L.) cvs DL 153‐2 and HD 2285 (relatively tolerant), HD 2329 and WH 542 (relatively susceptible), were grown under normal (27 November) and late (28 December) sown conditions. In another experiment, these cultivars were grown under normal sowing and at anthesis stage, they were transferred to control (C) and heated (H) open top chambers (OTCs). Under late sowing, wheat cultivars were exposed to a mean maximum temperature of up to 3.6 °C higher than normal sowing and in H‐OTCs, mean maximum temperature was 3.2 °C higher than C‐OTCs during grain growth period. Heat susceptibility index (S) for grain growth and grain yield was determined at maturity in both the experiments. The level of heat shock protein (HSP 18) in the developing grains was determined in C‐ and H‐OTC grown plants and in normal and late sown plants by Western blot analysis. The moderately high temperature exposure increased the accumulation of HSP 18 in the developing grains. The relatively tolerant cultivars, as also revealed from S, showed a greater increase in HSP 18 compared with susceptible types in response to moderate heat stress. An association of HSP 18 with thermotolerance for grain growth in wheat was indicated.
Mapping QTL for porcine muscle fibre traits in a White Duroc × Erhualian F2 resource population
Authors: Li W.B. , Ren J. , Zhu W.C. , Guo B.L. , Yang B. , Liu L.T. , Ding N.S. , Ma J.W. , Li L. , Huang L.S.
Published: August 2009

Muscle fibre traits are related with meat quality in meat animals. In this study, a whole‐genome scan with 183 microsatellite markers covering the pig genome was performed to identify quantitative trait loci (QTL) for cross‐sectional area, numerical percentage and relative area of type I, IIA and IIB myofibres, fibre number per square centimetre and total fibre number in the longissimus muscle by using 120 F2 animals in a White Duroc × Erhualian intercross. In total, 20 QTL were mapped on pig chromosomes (SSC) 1, 2, 7, 8, 9, 11, 15, 16 and X, of which eight reached genome‐wide significance levels and explained large proportions (6.53–34.63%) of phenotypic variance. Five QTL detected in this study confirmed the previous QTL reports and the others were detected for the first time. Chinese Erhualian alleles are generally associated with muscle fibre traits favourable for meat quality.
Variation in resistance to the Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) in Pietrain and Miniature pigs
Authors: Reiner G. , Willems H. , Pesch S. , Ohlinger V.F.
Published: August 2009

Porcine reproductive and respiratory syndrome (PRRS) is one of the economically most important diseases of swine. Viraemia and the prolonged persistence of the virus are among the most critical factors. Virus replication and severity of disease vary with virus isolates, and there is rising evidence for a genetic component of the host susceptibility. Dissecting the genetic basis of resistance/susceptibility to PRRS virus (PRRSV) might lead to improved knowledge on the molecular mechanisms of PRRS and the establishment of genetic markers for future disease control. The aim of this study was to establish a porcine model with emphasized genetic differences in PRRSV susceptibility. Seven ‘Wiesenauer Miniature’ pigs (MI), a local German breed and eight commercial Pietrain (PI) pigs were challenged with 105 TCID50 of an attenuated PRRSV strain (Ingelvac® PRRSV MLV). Clinical status, viraemia and seroconversion of the pigs were compared. No clinical signs were observed during the experiment. Viraemia peaked on day 6 p.i., with 100% of viraemic pigs in PI and on day 12 p.i with 87% of viraemic MI. Viraemia lasted for up to 35 days in MI and for at least 72 days in PI. This surprising result was confirmed by a second study with another four MI. MI and PI showed maximum virus titres of 102.5 TCID50/ml of serum and 104.5 TCID50/ml, respectively, indicating a virus replication in MI of approximately 3.3% that of PI over the complete period. MI were more efficient in antibody production. With such pronounced breed differences, the model is of high relevance for the genetic dissection of PRRS pathogenesis and susceptibility.
Use of serial pig body weights for genetic evaluation of daily gain
Authors: Zumbach B. , Misztal I. , Chen C.Y. , Tsuruta S. , Łukaszewicz M. , Herring W.O. , Culbertson M.
Published: August 2009

This study examined the utility of serial weights from FIRE (Feed Intake Recording Equipment, Osborne Industries, Inc., Osborne, KS, USA) stations for an analysis of daily gain. Data included 884 132 body weight records from 3888 purebred Duroc pigs. Pigs entered the feeder station at age 77–149 days and left at age 95–184 days. A substantial number of records were abnormal, showing body weight close to 0 or up to twice the average weight. Plots of body weights for some animals indicated two parallel growth curves. Initial editing used a robust regression, which was a two‐step procedure. In the first step, a quadratic growth curve was estimated assuming small or 0 weights for points far away from the curve; the process is iterative. In the second step, weights more than 1.5 SD from the estimated growth curve were treated as outliers. The retained body weight records (607 597) were averaged to create average daily weight (170 443) and then used to calculate daily gains (152 636). Additional editing steps included retaining only animals with ≥50 body weight records and SD of the daily gain ≤2 kg, followed by removing records outside 3 SD from the mean for given age, across all the animals – the resulting data set included 69 068 records of daily gain from 1921 animals. Daily gain based on daily, weekly and bi‐weekly intervals was analysed using repeatability models. Heritability estimates were 0.04, 6 and 9%, respectively. The last two estimates correspond to heritability of 28% for a 12 week interval. For daily gain averaged weekly, the estimate of heritability obtained with a random regression model varied from 0.07 to 0.10. After extensive editing, body weight records from automatic feeding stations are useful for genetic analyses of daily gain from weekly or bi‐weekly but not daily intervals.
Genetic and Molecular Characterization of Vernalization Genes Vrn‐A1, Vrn‐B1, and Vrn‐D1 in Spring Wheat Germplasm from the Pacific Northwest Region of the U.S.A.
Authors: Santra D. K. , Santra M. , Allan R. E. , Campbell K. G. , Kidwell K. K.
Published: August 2009

The objective of this study was to determine the Vrn‐1 allelic composition of spring wheat germplasm from the Pacific Northwest region of the USA. Individual plants from 56 spring wheat lines were crossed to near‐isogenic tester lines carrying the dominant allele Vrn‐A1, Vrn‐B1 or Vrn‐D1. F2 progeny were evaluated for growth habit in the field and Vrn‐1 allelic composition was determined through chi‐square analysis. Lines also were analysed with DNA sequence‐based Vrn‐1 allele‐specific markers. A majority of the germplasm carried the dominant allele Vrn‐A1a alone or in combination with Vrn‐B1, Vrn‐D1 or Vrn‐B3 alleles. Vrn‐B1 and Vrn‐D1 were almost always associated with other dominant Vrn‐1 allele(s). Based on DNA sequence analysis, a novel Vrn‐B1 allele referred to as Vrn‐B1b, which carried a single nucleotide polymorphism (SNP) and a 36 bp deletion, was identified in cultivar ‘Alpowa’. These results will be useful to wheat breeders for choosing parents with different Vrn‐1 alleles for crossing to maximize diversity at the Vrn‐1 loci with an expectation of identifying superior Vrn‐1 allelic combinations for cultivar improvement.
Use of Hand Held Doppler to identify venous tributaries in in situ vein arterial bypass
Authors: Riaz Amjid A. , Shukla Rajeev , Ng K. L. , Ormiston Michael C.
Published: August 2009

Background:  It very important to reduce the morbidity associated with arterial bypass surgery by minimizing the length of incision used in infrainguinal bypass surgery using in situ vein as a conduit. This paper describes a quick and less invasive method of identifying the location of vein tributaries using Hand Held Doppler in arterial bypass surgery with local cut down instead of extensive exposure.

Methods:  The technique was used in 19 consecutive procedures. Fourteen grafts were subsequently evaluated for completeness of tributary ligation using duplex scanning.

Results:  A mean of 2.5 tributaries were identified per limb. Thus, there were 35 patent tributaries in our cohort of 14 patients. None was of clinical significance. Four occluded spontaneously during the period of study. Wound length was reduced by 30–60% depending on the total length of the incision.

Conclusion:  This technique is an effective, cheap and simple means of performing bypass surgery in high‐risk patients (with significant comorbidity and a high ASA score) and also reducing inherent complications associated with the length of the incision.
Burnout in Australasian Younger Fellows
Authors: Benson Sarah , Sammour Tarik , Neuhaus Susan J. , Findlay Bruce , Hill Andrew G.
Published: August 2009

Background:  Burnout is the state of prolonged physical, emotional and psychological exhaustion characteristic of individuals working in human service occupations. This study examines the prevalence of burnout among Younger Fellows of the Royal Australasian College of Surgeons and its relationship to demographic variables.

Methods:  In March 2008, a survey was sent via email to 1287 Younger Fellows. This included demographic questions, a measure of burnout (Copenhagen Burnout Inventory), and an estimate of social desirability (Marlowe–Crowne Social Desirability Scale – Form C).

Results:  Females exhibited higher levels of personal burnout (P < 0.001) and work‐related burnout (P < 0.025), but no significant difference in patient‐related burnout. Younger Fellows in hospitals with less than 50 beds reported significantly higher patient‐related burnout levels (mean burnout 37.0 versus 22.1 in the rest, P= 0.004). An equal work division between public and private practice resulted in higher work‐related burnout than concentration of work in one sector (P < 0.05). Younger Fellows working more than 60 hours per week reported significantly higher personal burnout than those who worked less than this (P < 0.05). There was no significant correlation between age, country of practice, surgical specialty and any of the burnout subscales.

Conclusion:  Female surgeons, surgeons that work in smaller hospitals, those that work more than 60 h per week, and those with practice division between the private and public sectors, are at a particularly high risk of burnout. Further enquiry into potentially remediable causes for the increased burnout in these groups is indicated.
The impact of the evolution of invasive surgical procedures for low back pain: a population based study of patient outcomes and hospital utilization
Authors: Moorin Rachael Elizabeth , Holman C. D'Arcy J.
Published: August 2009

Background:  Low back pain (LBP) is a ubiquitous health problem in Western societies, and while clinical decision making for patients requiring hospitalization for LBP has changed significantly over the past two decades, knowledge of the net impact on patient outcomes and health care utilization is lacking. The aim of this study was to evaluate the effectiveness of changes in the medical control of lumbar back pain in Western Australia in terms of the rate of patient readmission and the total bed days associated with readmissions.

Methods:  A record linkage population‐based study of hospitalization for LBP from 1980–2003 in Western Australia was performed. The rate of admission for LBP, changes in re‐admission rates and number of bed days accrued 1 and 3 years post‐initial admission over time adjusted for potential confounders was evaluated.

Results:  The annual rate of first‐time hospitalization for LBP halved. The proportion of females admitted increased (+6%). The disease severity increased and the proportion of individuals having an invasive procedure also increased (+75%) over the study period. While rate of readmission for non‐invasive procedures fell, readmission for invasive procedures increased over the study period. Overall, the number of bed days associated with readmission reduced over time.

Conclusion:  Between 1980 and 2003, there has been a shift from non‐invasive procedural treatments towards invasive techniques both at the time of initial hospitalization and upon subsequent readmission. While overall readmission rates were unaffected, there was a reduction in the number of bed days associated with readmissions.
Linezolid versus vancomycin for MRSA skin and soft tissue infections (systematic review and meta‐analysis)
Authors: Dodds Tristan John , Hawke Catherine Isobel
Published: August 2009

Background:  This review aims to compare the effectiveness of linezolid to vancomycin for the treatment of Methicillin Resistant Staphylococcus Aureus (MRSA) skin and soft tissue infections (SSTIs) in inpatients.

Methods:  MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials and reference lists were searched in March 2007. We included randomized controlled trials that looked at inpatients treated with linezolid versus vancomycin for the treatment of hospital‐acquired MRSA SSTIs. Outcome measures were clinical cure (resolution of symptoms and signs) and microbiological cure (eradication of MRSA on wound culture). The validity of the included trials was assessed. The results were combined in meta‐analyses, the robustness of which was tested in sensitivity analyses.

Results:  Four trials were included in this review: three for clinical outcomes (174 participants) and three for microbiological outcomes (439 participants). For clinical outcomes there were non‐significant trends in favour of linezolid (RR 0.34; 95% CI 0.04, 2.89; P = 0.32). For microbiological outcomes there was weak evidence of linezolid outperforming vancomycin (RR 0.55; 95% CI 0.30, 1.01; P = 0.05). Sensitivity analyses did not change the conclusions taken from the main analysis.

Conclusion:  With the current available data no difference could be detected between the two treatments, but a trend towards higher effectiveness of linezolid was observed. More data will be required to determine if linezolid is superior to vancomycin for the treatment of MRSA SSTIs. Further systematic reviews are needed to look at other outcomes (length of hospital stay, safety and tolerability, cost‐effectiveness) and at MRSA infections at other sites.
Case cancellations on the day of surgery: an investigation in an Australian paediatric hospital
Authors: Haana Victoria , Sethuraman Kannan , Stephens Lisa , Rosen Heather , Meara John G.
Published: August 2009

Background:  This study investigates case cancellations on the intended day of surgery (DOS) at a paediatric hospital in Melbourne, Australia. The hospital in Melbourne treats over 32 000 inpatients annually and handles both elective and emergency cases.

Methods:  The data for this paper were collected over a period of 12 months, from June 2004 to June 2005. The data were extracted retrospectively from the theatre computer system. A nurse researcher reviewed the full written details of all cancellations to clarify their cause and confirm the reasons for cancellation; the reasons for cancellation were then sorted into one of 14 groups.

Results:  There were 16 559 theatre bookings, and of these, 1198 (7.2%) were cancelled on the DOS. There was a mean of 3.28 cancellations of surgery on the intended day. The hospital‐initiated postponements accounted for 18.5% of DOS cancellations. The top four reasons for cancellation accounted for 65% of all cancelled surgeries and were all patient initiated.

Conclusions:  There was also evidence that some specialties were more susceptible to DOS cancellation than others. The paper ends with proposals to reduce patient‐initiated cancellations and directions for future research.
Prolonging androgen sensitivity in prostate cancer – a role for COX inhibitors?
Authors: Richards Andrew , McGeechan Kevin , Niknam Marzieh , Salomon Robert , Kurek Caroline , Dong Qihan , Patel Manish I.
Published: August 2009

Background:  Advanced prostate cancer has long been known to respond to androgen deprivation, but disease inevitably progresses to become androgen independent. Lengthening the responsive period is an important, yet underinvestigated, clinical goal. This study aims to determine whether cyclooxygenase‐2 (COX‐2) inhibitors are potentially useful agents in prolonging androgen sensitivity.

Methods:  The expression of COX‐2 in human prostate surgical specimens, both benign and malignant, androgen dependent and independent, was determined by immunohistochemistry. Nude mice, in which prostate cancer xenografts had been established, were castrated and randomized to receive either COX‐2 inhibitor or vehicle for 8 weeks. Time to androgen independence (AIPC), growth rate and rate of PSA rise were compared between groups. COX‐2 expression, at the mRNA and protein level, was determined in the native xenograft cell line and in tissues of varying androgen sensitivity derived from the xenografts.

Results:  In human tissues, COX‐2 protein was expressed in prostate epithelium and was upregulated in prostate cancer and remained upregulated after androgen ablation and in the androgen‐independent state. Tissue obtained from the LNCaP xenograft model showed variable COX‐2 expression, with some evidence of downregulation in AIPC. The addition of a COX‐2 inhibitor to castration does not lengthen the time to AIPC (P= 0.53), rate of tumour growth (P= 0.59) or rate of PSA rise (P= 0.34) in the LNCaP xenograft model.

Conclusion:  This study does not support a role for COX‐2 inhibitors in prolonging androgen responsiveness in prostate cancer.
Genetically‐based trade‐offs in response to stoichiometric food quality influence competition in a keystone aquatic herbivore
Authors: Jeyasingh Punidan D. , Weider Lawrence J. , Sterner Robert W.
Published: August 2009

The genetic basis of organism response to stoichiometric mismatches between environmental availability and somatic demand is still poorly understood. This study reports a consistent genotype × environment interaction related to phosphorus : carbon availability to Daphnia. In multiple pairs of Daphnia pulicaria clones, genetic variation at the phosphoglucose isomerase (Pgi) locus indicated that Pgi‐heterozygotes out competed Pgi‐homozygotes under high P : C conditions, whereas the opposite outcome was observed under low P : C conditions. Estimates of phosphorus use efficiency indicated that homozygotes were significantly more efficient. However, homozygotes were comparatively less homeostatic. We hypothesize that lower specific activity of Pgi from homozygotes, which results in lowered energetic efficiency during the second glycolytic step, may underlie the competitive advantage enjoyed by homozygotes under low P : C (i.e. excess C) conditions. Our results show that analysing stoichiometric mismatches between diet and consumer should advance our quest for a fundamental understanding of the mechanisms driving genotype‐environment interactions.
Seed arrival, ecological filters, and plant species richness: a meta‐analysis
Authors: Myers Jonathan A. , Harms Kyle E.
Published: September 2009

Theoretical models predict that effects of dispersal on local biodiversity are influenced by the size and composition of the species pool, as well as ecological filters that limit local species membership. We tested these predictions by conducting a meta‐analysis of 28 studies encompassing 62 experiments examining effects of propagule supply (seed arrival) on plant species richness under contrasting intensities of ecological filters (owing to disturbance and resource availability). Seed arrival increased local species richness in a wide range of communities (forest, grassland, montane, savanna, wetland), resulting in a positive mean effect size across experiments. Mean effect size was 70% higher in disturbed relative to undisturbed communities, suggesting that disturbance increases recruitment opportunities for immigrating species. In contrast, effect size was not significantly influenced by nutrient or water availability. Among seed‐addition experiments, effect size was positively correlated with species and functional diversity within the pool of added seeds (species evenness and seed‐size diversity), primarily in disturbed communities. Our analysis provides experimental support for the general hypothesis that species pools and local environmental heterogeneity interactively structure plant communities. We highlight empirical gaps that can be addressed by future experiments and discuss implications for community assembly, species coexistence, and the maintenance of biodiversity.
Dispersal and natural enemies interact to drive spatial synchrony and decrease stability in patchy populations
Authors: Vogwill Tom , Fenton Andy , Brockhurst Michael A.
Published: August 2009

Spatial synchrony is widespread in natural populations but the mechanisms that underpin it are not yet fully understood. Two key biotic drivers of spatial synchrony have been identified: dispersal and trophic interactions (e.g. natural enemies). We used spatially structured, patchy bacterial populations to show that although increased dispersal always enhanced spatial synchrony of fluctuations in bacterial abundance, this effect was far stronger in the presence of a bacteriophage parasite. Bacteriophages drove strong within patch fluctuations in bacterial abundance that became phase locked through dispersal. Furthermore, the way in which stability, measured as constancy, responded to increasing dispersal was qualitatively different depending on whether parasites were present or not. Patch‐level constancy decreased with dispersal in the presence of parasites, whereas dispersal increased patch‐level constancy in the absence of parasites. Population‐level constancy also decreased with dispersal in the presence of parasites, but was unaffected by dispersal in the absence of parasites. These contrasting patterns were likely due to the different role played by dispersal in the presence and absence of parasites, synchronizing dynamics in the former case and averaging stochastic fluctuations in the latter. Taken together, our findings suggest that dispersal and natural enemies can interact to drive spatially synchronous population fluctuations that decrease stability at both the patch and population level.
Ultrastructural changes in skeletal muscle of the tail of the lizardHemidactylus mabouiaimmediately following autotomy
Authors: Araújo Tomaz Henrique , Faria Flavio Pavla de , Katchburian Eduardo , Haapalainen Edna Freymüller
Published: August 2009

Araújo, T.H., Faria, F.P., Katchburian, E. and Freymüller, E. (2009). Ultrastructural changes in skeletal muscle of the tail of the lizardHemidactylus mabouiaimmediately following autotomy. —Acta Zoologica(Stockholm)91: 440–446.

Although autotomy and subsequent regeneration of lizard tails has been extensively studied, there is little information available on ultrastructural changes that occur to the muscle fibers at the site of severance. Thus, in the present study, we examine the ultrastructure of the musculature of the remaining tail stump of the lizardHemidactylus mabouiaimmediately after autotomy. Our results show that exposed portions of the skeletal muscle fibers of the stump that are unprotected by connective tissue bulge to produce large mushroom‐like protrusions. These exposed portions show abnormal structure but suffer no leakage of cytoplasmic contents. Many small and large vesicular structures appeared between myofibrils in the interface at this disarranged region (distal) and the other portion of the fibers that remain unchanged (proximal). These vesicles coalesce, creating a gap that leads to the release of the mushroom‐like protrusion. So, our results showed that after the macroscopic act of autotomy the muscular fibers release part of the sarcoplasm as if a second and microscopic set of autotomic events takes place immediately following the macroscopic act of autotomy. Presumably these changes pave the way for the formation of a blastema and the beginning of regeneration.
Spermatogenesis in Boccardiella hamata (Polychaeta: Spionidae) from the Sea of Japan: sperm formation mechanisms as characteristics for future taxonomic revision
Authors: Reunov Arkadiy A. , Yurchenko Olga V. , Alexandrova Yana N. , Radashevsky Vasily I.
Published: August 2009

Reunov, A.A., Yurchenko, O.V., Alexandrova, Y.N. and Radashevsky, V.I. 2009. Spermatogenesis in Boccardiella hamata (Polychaeta: Spionidae) from the Sea of Japan: sperm formation mechanisms as characteristics for future taxonomic revision. —Acta Zoologica (Stockholm) 91: 477–456.

To characterize novel features that will be useful in the discussion and validation of the spionid polychaete Boccardiella hamata from the Sea of Japan, the successive stages of spermatogenesis were described and illustrated. Spermatogonia, spermatocytes and early spermatids are aflagellar cells that develop synchronously in clusters united by a cytophore. At the middle spermatid stage, the clusters undergo disintegration and spermatids produce flagella and float separately in coelomic fluid as they transform into sperm. Spermatozoa are filiform. The ring‐shaped storage platelets are located along the anterior nuclear area. The nucleus is cupped by a conical acrosome. A nuclear plate is present between the acrosome and nucleus. The nucleus is a cylinder with the implantation fossa throughout its length and with the anterior part of the flagellum inside the fossa. There is only one centriole, serving as a basal body of the flagellum, situated in close vicinity of the acrosomal area. A collar of four mitochondria is located under the nuclear base. The ultrastructure of B. hamata spermatozoa from the Sea of Japan appears to be close to that of B. hamata from Florida described by Rice (Microscopic Anatomy of Invertebrates, Wiley‐Liss, Inc., New York, 1992), suggesting species identity of the samples from the two regions. However, more detailed study of Florida’s B. hamata sperm is required for a reliable conclusion concerning the similarity of these two polychaetes. In addition to sperm structure, features such as the cytophore‐assigned pattern of spermatogenic cell development, the synchronous pattern of cell divisions, the non‐flagellate early spermatogenic stages, and the vesicle amalgamation that drives meiotic cell cytokinesis and spermatid diorthosis will likely be useful in future testing of the validity of B. hamata and sibling species throughout the world.
Clinical experience in a modified Roux‐Y‐ shaped sigmoid neobladder: assessment of complications and voiding patterns in 43 patients
Authors: Liu DingYi , Feng Feng , Shen ZhouJun , Xia WeiMu , Zhou WenLong , Wang MingWei , Zhu Yu , Wang Jian , Tang Qi
Published: August 2009

Study Type – Therapy (case series)Level of Evidence 4

OBJECTIVE

To evaluate the complications and urinary voiding patterns in patients with a new Roux‐Y‐shaped continent neobladder, using a modified sigmoid pouch.

PATIENTS AND METHODS

Between June 2003 and July 2008, 43 patients (26 men and 17 women, mean age 69.5 years) underwent a modified Roux‐Y‐shaped sigmoid continent neobladder reconstruction after radical cystectomy. The surgical procedures involved the construction of a Roux‐Y‐shaped sigmoid pouch, making an antifeces‐refluxing valve into the sigmoid urine reservoir and ureterosigmoidostomy using the Leadbetter method. This pouch method has not been described before. The patients’ clinical, biochemical, radiological and urodynamic variables were assessed.

RESULTS

During the mean (range) follow‐up of 24 (6–65) months, there were no deaths related to the procedure. In 16% of the patients, early complications occurred, whereas 12% had late complications. There were no cases with local recurrence and metastasis. Routine electrolyte evaluation revealed a slight metabolic acidosis in six patients (14%). Hypovitaminosis B12 did not occur in any patients. All patients were continent in the daytime and night‐time continence was poor in eight patients (19%). The mean (sd, range) neobladder capacity and residual urine volume was 330 (110, 120–410) mL and 48 (26, 25–80) mL, respectively. Moreover, the maximum urinary flow rate was 9.2–25.3 mL/s.

CONCLUSION

The modified Roux‐Y‐shaped sigmoid neobladder replacement provides a new simple surgical procedure with low complication rates. The procedure offers comparatively satisfactory daytime continence with low postvoid residual urine volumes and voiding patterns. This technique is a valid alternative to continent urinary diversion.
Fast, Exact, Linear Booleans
Authors: Bernstein Gilbert , Fussell Don
Published: August 2009

We present a new system for robustly performing Boolean operations on linear, 3D polyhedra. Our system is exact, meaning that all internal numeric predicates are exactly decided in the sense of exact geometric computation. Our BSP‐tree based system is 16‐28× faster at performing iterative computations than CGAL's Nef Polyhedra based system, the current best practice in robust Boolean operations, while being only twice as slow as the non‐robust modeler Maya. Meanwhile, we achieve a much smaller substrate of geometric subroutines than previous work, comprised of only 4 predicates, a convex polygon constructor, and a convex polygon splitting routine. The use of a BSP‐tree based Boolean algorithm atop this substrate allows us to explicitly handle all geometric degeneracies without treating a large number of cases.
Interior Distance Using Barycentric Coordinates
Authors: Rustamov R. M. , Lipman Y. , Funkhouser T.
Published: August 2009

This paper introduces a framework for defining a shape‐aware distance measure between any two points in the interior of a surface mesh. Our framework is based on embedding the surface mesh into a high‐dimensional space in a way that best preserves boundary distances between vertices of the mesh, performing a mapping of the mesh volume into this high‐dimensional space using barycentric coordinates, and defining the interior distance between any two points simply as their Euclidean distance in the embedding space. We investigate the theoretical properties of the interior distance in relation to properties of the chosen boundary distances and barycentric coordinates, and we investigate empirical properties of the interior distance using diffusion distance as the prescribed boundary distance and mean value coordinates. We prove theoretically that the interior distance is a metric, smooth, interpolating the boundary distances, and reproducing Euclidean distances, and we show empirically that it is insensitive to boundary noise and deformation and quick to compute. In case the barycentric coordinates are non‐negative we also show a maximum principle exists. Finally, we use it to define a new geometric property, barycentroid of shape, and show that it captures the notion of semantic center of the shape.
Diamond Hierarchies of Arbitrary Dimension
Authors: Weiss Kenneth , De Floriani Leila
Published: August 2009

Nested simplicial meshes generated by the simplicial bisection decomposition proposed by Maubach [Mau95] have been widely used in 2D and 3D as multi‐resolution models of terrains and three‐dimensional scalar fields, They are an alternative to octree representation since they allow generating crack‐free representations of the underlying field. On the other hand, this method generates conforming meshes only when all simplices sharing the bisection edge are subdivided concurrently. Thus, efficient representations have been proposed in 2D and 3D based on a clustering of the simplices sharing a common longest edge in what is called a diamond. These representations exploit the regularity of the vertex distribution and the diamond structure to yield an implicit encoding of the hierarchical and geometric relationships among the triangles and tetrahedra, respectively. Here, we analyze properties ofd‐dimensional diamonds to better understand the hierarchical and geometric relationships among the simplices generated by Maubach's bisection scheme and derive closed‐form equations for the number of vertices, simplices, parents and children of each type of diamond. We exploit these properties to yield an implicit pointerless representation ford‐dimensional diamonds and reduce the number of required neighbor‐finding accesses fromO(d!) toO(d).
Progressive Lossless Mesh Compression Via Incremental Parametric Refinement
Authors: Valette Sébastien , Chaine Raphaëlle , Prost Rémy
Published: August 2009

In this paper, we propose a novel progressive lossless mesh compression algorithm based on Incremental Parametric Refinement, where the connectivity is uncontrolled in a first step, yielding visually pleasing meshes at each resolution level while saving connectivity information compared to previous approaches. The algorithm starts with a coarse version of the original mesh, which is further refined by means of a novel refinement scheme. The mesh refinement is driven by a geometric criterion, in spirit with surface reconstruction algorithms, aiming at generating uniform meshes. The vertices coordinates are also quantized and transmitted in a progressive way, following a geometric criterion, efficiently allocating the bit budget. With this assumption, the generated intermediate meshes tend to exhibit a uniform sampling. The potential discrepancy between the resulting connectivity and the original one is corrected at the end of the algorithm. We provide a proof‐of‐concept implementation, yielding very competitive results compared to previous works in terms of rate/distortion trade‐off.
Random Accessible Hierarchical Mesh Compression for Interactive Visualization
Authors: Courbet Clement , Hudelot Celine
Published: August 2009

This paper presents a novel algorithm for hierarchical random accessible mesh decompression. Our approach progressively decompresses the requested parts of a mesh without decoding less interesting parts. Previous approaches divided a mesh into independently compressed charts and a base coarse mesh. We propose a novel hierarchical representation of the mesh. We build this representation by using a boundary‐based approach to recursively split the mesh in two parts, under the constraint that any of the two resulting submeshes should be reconstructible independently.

In addition to this decomposition technique, we introduce the concepts of opposite vertex and context dependant numbering. This enables us to achieve seemingly better compression ratios than previous work on quad and higher degree polygonal meshes. Our coder uses about 3 bits per polygon for connectivity and 14 bits per vertex for geometry using 12 bits quantification.