bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pronounced seasonal dynamics of freshwater chitinase genes and chitin processing
Authors: Beier Sara , Mohit Vani , Ettema Thijs J. G. , Östman Örjan , Tranvik Lars J. , Bertilsson Stefan 
Published: May 2012

SummarySeasonal variation in activity of enzymes involved in polymer degradation, including chitinases, has been observed previously in freshwater environments. However, it is not known whether the seasonal dynamics are due to shifts in the activity of bacteria already present, or shifts in community structure towards emergence or disappearance of chitinolytic organisms. We traced seasonal shifts in the chitinase gene assemblage in a temperate lake and linked these communities to variation in chitinase activity. Chitinase genes from 20 samples collected over a full yearly cycle were characterized by pyrosequencing. Pronounced temporal shifts in composition of the chitinase gene pool (beta diversity) occurred along with distinct shifts in richness (alpha diversity) as well as chitin processing. Changes in the chitinase gene pool correlated mainly with temperature, abundance of crustacean zooplankton and phytoplankton blooms. Also changes in the physical structure of the lake, e.g. stratification and mixing were associated with changes in the chitinolytic community, while differences were minor between surface and suboxic hypolimnetic water. The lake characteristics influencing the chitinolytic community are all linked to changes in organic particles and we suggest that seasonal changes in particle quality and availability foster microbial communities adapted to efficiently degrade them.
Prokaryotic communities and operating metabolisms in the surface and the permafrost of Deception Island (Antarctica)
Authors: Blanco Yolanda , Prieto‐Ballesteros Olga , Gómez Manuel J. , Moreno‐Paz Mercedes , García‐Villadangos Miriam , Rodríguez‐Manfredi José A. , Cruz‐Gil Patricia , Sánchez‐Román Mónica , Rivas Luis A. , Parro Victor 
Published: May 2012

SummaryIn this study we examined the microbial community composition and operating metabolisms on the surface and in the permafrost of Deception Island, (Antarctica) with an on site antibody microarray biosensor. Samples (down to a depth of 4.2 m) were analysed with LDChip300 (Life Detector Chip), an immunosensor containing more than 300 antibodies targeted to bacterial and archaeal antigens. The immunograms showed positive antigen‐antibody reactions in all surface samples (lichens, pyroclasts) and the top layer of the permafrost. The results indicated the presence of exopolysaccharides, bacteria belonging to the Alpha‐, Delta‐ and Gammaproteobacteria, Bacteroidetes, Gram‐positive Actinobacteria and Firmicutes, as well as archaeal species, most probably Methanobacterium spp. Positive reactions with antibodies to proteins and peptides revealed the presence of nitrogen fixation (NifHD, GlnB, HscA), methanogenic (McrB), iron homeostasis and iron scavenging (ferritins and DPS proteins) proteins, as well as ABC transporters, which indicated that these processes were operating at the time of sampling. These results were validated with other molecular ecology techniques such as oligonucleotide microarrays, 16S bacterial rRNA gene sequence analysis, aerobic viable counts and microscopy. Molecular ecology results showed a differentiated pattern along the depth of the drill, being the top active layer the most diverse, with Acidobacteria, Actinobacteria, Proteobacteria, Bacteroidetes and the phototrophs Cyanobacteria and Chloroflexi as dominant groups. Actinobacteria and Firmicutes were dominant in depths from 0.5 to 2 m, and Betaproteobacteria from 3 to 4.2 m. The geochemical analysis revealed the presence of low molecular weight organic acids (acetate, formate) which could be used by microorganisms as energy sources for sulfate, nitrate and metal reduction under anaerobic conditions.
Bacterioplankton groups involved in the uptake of phosphate and dissolved organic phosphorus in a mesocosm experiment with P‐starved Mediterranean waters
Authors: Sebastián Marta , Pitta Paraskevi , González José M. , Thingstad T. Frede , Gasol Josep M. 
Published: May 2012

SummaryThe use of inorganic phosphate (Pi) and dissolved organic phosphorus (DOP) by different bacterial groups was studied in experimental mesocosms of P‐starved eastern Mediterranean waters in the absence (control mesocosms) and presence of additional Pi (P‐amended mesocosms). The low Pi turnover times in the control mesocosms and the increase in heterotrophic prokaryotic abundance and production upon Pi addition confirmed that the bacterial community was originally P‐limited. The bacterioplankton groups taking up Pi and DOP were identified by means of microautoradiography combined with catalysed reporter deposition fluorescence in situ hybridization. Incubations with leucine were also performed for comparative purposes. All the probe‐identified groups showed a high percentage of cells taking up Pi and DOP in the control, P‐limited, mesocosms throughout the experiment. However, in response to Pi addition two contrasting scenarios in Pi use were observed: (i) on day 1 of the experiment Pi addition caused a clear reduction in the percentage of SAR11 cells taking up Pi, whereas Gammaproteobacteria, Roseobacter and Bacteroidetes showed similar percentages to the ones in the control mesocosms and (ii) on day 4 of the experiment, probably when the bacterial community had fully responded to the P input, all the probe‐identified groups showed low percentages of cells taking up the substrate as compared with the control mesocosms. These differences are likely related to different P requirements among the bacterial groups and point out to the existence of two contrasting strategies in P use.
Current UK management of locally recurrent rectal cancer
Authors: Harji D. P. , Griffiths B. , McArthur D. R. , Sagar P. M. 
Published: May 2012

AbstractAim  The study aimed to determine current UK practice in the management of locally recurrent rectal cancer (LRRC).Method  An electronic based survey was sent to UK based Association of Coloproctology of Great Britain and Ireland members to establish current management in this patient group. A total of 188 questionnaires were sent out to consultant surgeons in a total of 105 colorectal units.Results  Seventy‐nine consultants from 69 units responded, giving an overall response rate from consultants of 42% and from colorectal units of 66%. In all, 688 patients were managed by multidisciplinary teams in the 12 months prior to the survey. Seventy‐four (94% of responders) surgeons had experience of operating on patients with LRRC. Fifty‐nine (74.6%) operated on one to three per year and four (5%) operated on more than 10 patients per year. Central and anterior recurrences were most commonly undertaken locally, with most complex recurrences being referred to a tertiary centre. Forty‐seven (61%) surgeons worked to an algorithm.Conclusion  A small number of specialist units in the UK manage the full spectrum of LRRC but the majority of patients are managed in small volume centres. The survey provides a snapshot of current activity in the UK and may provide a stimulus for discussion about how to expand and improve the care of a technically challenging group of patients.
Surgery for recurrent rectal cancer: higher and wider?
Authors: Harji D. P. , Griffiths B. , McArthur D. R. , Sagar P. M. 
Published: May 2012

AbstractAim  There has been a steady increase in the number of centres that carry out resection of locally recurrent rectal cancer (LRRC). The aim of this review was to highlight the present management and suggest technical strategies that may improve survival and quality of life.Method  The review identified relevant studies from an electronic search of MEDLINE and PubMed databases between 1980 and 2011. References in published articles were also reviewed.Results  Surgical intervention offers the best hope to control LRRC but the proportion of patients offered this remains small. Certain contraindications previously considered to be absolute should now be thought of as relative.Conclusion  Awareness of the surgical options and a willingness to consider more aggressive options may result in more patients being considered for potentially curative resection.
Intra‐operative tumour detection and staging in colorectal cancer surgery
Authors: Tiernan J. P. , Ansari I. , Hirst N. A. , Millner P. A. , Hughes T. A. , Jayne D. G. 
Published: May 2012

AbstractAim  Surgical resection for colorectal cancer involves segmental resection and regional lymphadenectomy. The appropriateness of this ‘one‐size‐fits‐all’ strategy is questioned as bowel cancer screening programmes result in a shift to earlier stage disease. Currently, the nodal status of a colorectal cancer can only be reliably determined by histopathological examination of the resected specimen. New methods of intra‐operative staging are required to allow surgical resection to be tailored to the stage of the disease.Method  A literature search was performed of PubMed and Embase databases using the terms ‘colon’ OR ‘colorectal’ AND ‘intra‐operative detection’ OR ‘intra‐operative staging’ OR ‘intra‐operative detection’ OR ‘radioimmunoguided surgery’. Articles published between January 1980 and January 2012 were included. Technologies that have the potential to allow intra‐operative staging and treatment stratification were identified and further searches performed.Results  Established techniques such as sentinel lymph node mapping and radioimmunoguided surgery have benefited from combination with other technologies to allow real‐time intra‐operative staging. Intra‐operative fluorescence, using naturally fluorescent biomarkers or fluorescent tumour probes, probably offers the most practical means of intra‐operative lymph node staging and may be facilitated using nanotechnology. Optical coherence tomography and real‐time elastography have the potential to provide an in vivo‘virtual biopsy’.Conclusion  Technological advances may allow accurate intra‐operative lymph node staging to facilitate tailored surgical resection. This may become the next paradigm shift in colorectal cancer surgery.
A nationwide study on anastomotic leakage after colonic cancer surgery
Authors: Krarup P.‐M. , Jorgensen L. N. , Andreasen A. H. , Harling H. ,   on behalf of the Danish Colorectal Cancer Group
Published: May 2012

AbstractAim  Anastomotic leakage (AL) is a major challenge in colorectal cancer surgery due to increased morbidity and mortality. Possible risk factors should be investigated differentially, distinguishing between rectal and colonic surgery in large‐scale studies to avoid selection bias and confounding.Method  The incidence and risk factors associated with AL were analysed in an unselected nationwide prospective cohort of patient subjected to curative colonic cancer surgery with primary anastomosis and entered into The Danish Colorectal Cancer Group database between May 2001 and December 2008.Results  AL occurred in 593 (6.4%) of 9333 patients. Laparoscopic surgery [odds ratio (OR) 1.34; 95% confidence interval (CI) 1.05–1.70; P = 0.03); left hemicolectomy (OR 2.02; 95% CI 1.50–2.72; P = 0.01) or sigmoid colectomy (OR 1.69; 95% CI 1.32–2.17; P = 0.01); intra‐operative blood loss (OR 1.04; 95% CI 1.01–1.07; P = 0.03); blood transfusion (OR 10.27; 95% CI 6.82–15.45; P < 0.001) and male gender (OR 1.41; 95% CI 1.12–1.75; P = 0.02) were associated with AL in the multivariate analysis.Conclusion  The main finding that a laparoscopic approach was associated with an increased risk of AL should prompt close future monitoring. There was no evidence that centralization of surgery to high‐volume hospitals reduced the rate of AL.
Metastatic castrate‐resistant prostate cancer: dawn of a new age of management
Authors: Masson Susan , Bahl Amit 
Published: May 2012

What's known on the subject? and What does the study add?Metastatic castrate‐resistant prostate cancer (mCRPC) was historically considered to be an aggressive disease resistant to conventional anticancer therapy. Within the last decade the outlook has changed beyond recognition; docetaxel chemotherapy is now firmly established as a well‐tolerated treatment with significant survival benefits. Building on this, more recently there have been several landmark developments using various approaches in patients whose disease has progressed despite previous chemotherapy. Cabazitaxel chemotherapy offers survival and health‐related quality of life (HRQL) improvements in this setting, as does the CYP inhibitor abiraterone acetate. Significant clinical benefits are also seen with novel radioisotope and immunotherapeutic approaches.There have been many developments in the management of this condition within the last 2 years, with several landmark studies showing new treatments that offer survival and HRQL benefits even in the setting of advanced disease, which has been heavily pretreated. This review article summarises these important developments and gives the reader an overview of current practice, recent changes and future directions.
With current and forthcoming developments in the treatment of metastatic castrate‐resistant prostate cancer (mCRPC) post‐docetaxel, we are embarking on an age of potential ‘chronic’ management of this disease.
It is hoped that the survival benefits associated with the various treatments, cytotoxic, hormonal and immunotherapeutic, will prove to be additive, providing a multimodal continuum of care. If so, it will be necessary to determine the optimal sequence and timing of the new treatments.
One key factor in this regard is likely to be the patient's performance status and hence his eligibility for cytotoxic intervention. If chemotherapy is offered early in the post‐docetaxel pathway, the patient may still be able to benefit from non‐chemotherapeutic options subsequently. However, if this stage of management begins with a non‐chemotherapeutic option, there is a risk that the patient's performance status will decline before he has an opportunity to benefit from chemotherapy.
Further studies and ongoing clinical experience are likely to clarify this important issue, and help clinicians to maximise the survival of men with mCRPC post‐docetaxel.
Reversing bladder outlet obstruction attenuates systemic and tissue oxidative stress
Authors: Lin Wei‐Yu , Wu Shi‐Bei , Lin Yi‐Pai , Chang Pey‐Jium , Levin Robert M. , Wei Yau‐Huei 
Published: May 2012

What's known on the subject? and What does the study add?Oxidative damage in bladder tissue and systemic oxidative biomarkers were both found to be increased in rabbits with partial bladder outlet obstruction.It is shown that the reversal of partial bladder outlet obstruction will attenuate the systemic oxidative stress.OBJECTIVE
To investigate whether partial bladder outlet obstruction (PBOO) increases systemic oxidative stress and whether relief of PBOO could attenuate this stress.
MATERIALS AND METHODS
Surgically created PBOO in male New Zealand white rabbits was assessed after 4 weeks in one group of rabbits (n = 4), and was relieved in two additional groups of rabbits (n = 4 each) that were assessed at 4 and 8 weeks after relief of PBOO.
Four sham‐operated rabbits served as controls. The assessed oxidative stress biomarkers included urinary and plasma 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG) and plasma malondialdehyde (MDA), total anti‐oxidant capacity (TAC) and glutathione (GSH).
In addition, the copy number of mitochondrial DNA and the 8‐OHdG content in bladder tissues from these rabbits were also determined at the beginning and at indicated time points in the experiments.
RESULTS
There were significant increases in both the 8‐OHdG levels of urine, plasma and bladder tissue and the plasma MDA after induction of PBOO.
There were also significant decreases in the TAC, in GSH levels and in mitochondrial DNA copy number in bladder tissues after PBOO.
Most importantly, all of the values returned toward the control levels after the PBOO was reversed at 8 weeks.
CONCLUSION
PBOO increases systemic and oxidative stress and its reversal results in a progressive reduction of both systemic and tissue oxidative stress.
Organizational Complexity and Auditor Quality
Authors: Liu Chih‐Liang , Lai Shu‐Miao 
Published: May 2012

ABSTRACTManuscript Type: EmpiricalResearch Question/Issue: This study investigates two questions: (1) What is the relationship between organizational complexity and auditor choice, and (2) Does auditor choice influence the relationship between organizational complexity and firm value?Research Findings/Insights: Examination of a sample of large public US companies reveals a positive association between auditor quality and various proxies for organizational complexity. We also find a positive association between organizational complexity and firm value when the complex firm hires Big N auditors. The results are robust to alternative measures of auditor quality and firm value and to controls for the regulatory environment.Theoretical/Academic Implications: The results extend the agency theory argument that agency costs resulting from information asymmetry between managers and investors affect the demand for external monitoring by auditors, specifically the demand by organizationally complex firms for higher quality audits. We also shed light on how the value enhancement of a complex organization depends on auditor quality.Practitioner/Policy Implications: Our findings offer new perspectives for managers of complex firms that are industrially or geographically diversified. They can use the retention of a larger auditor as a credible signal that their consolidated reports are more informative about their financial performance. Further, the findings provide new insight into the value that investors place on auditor quality when they assess the value of firms with complex organizational structures.
Nociceptive Neuropeptide Increases and Periorbital Allodynia in a Model of Traumatic Brain Injury
Authors: Elliott Melanie B. , Oshinsky Michael L. , Amenta Peter S. , Awe Olatilewa O. , Jallo Jack I. 
Published: May 2012

Objective.— This study tests the hypothesis that injury to the somatosensory cortex is associated with periorbital allodynia and increases in nociceptive neuropeptides in the brainstem in a mouse model of controlled cortical impact (CCI) injury.Methods.— Male C57BL/6 mice received either CCI or craniotomy‐only followed by weekly periorbital von Frey (mechanical) sensory testing for up to 28 days post‐injury. Mice receiving an incision only and naïve mice were included as control groups. Changes in calcitonin gene‐related peptide (CGRP) and substance P (SP) within the brainstem were determined using enzyme‐linked immunosorbent assay and immunohistochemistry, respectively. Activation of ionized calcium‐binding adaptor molecule‐1–labeled macrophages/microglia and glial fibrillary acidic protein (GFAP)‐positive astrocytes were evaluated using immunohistochemistry because of their potential involvement in nociceptor sensitization.Results.— Incision‐only control mice showed no changes from baseline periorbital von Frey mechanical thresholds. CCI significantly reduced mean periorbital von Frey thresholds (periorbital allodynia) compared with baseline and craniotomy‐only at each endpoint, analysis of variance P < .0001. Craniotomy significantly reduced periorbital threshold at 14 days but not 7, 21, or 28 days compared with baseline threshold, P < .01. CCI significantly increased SP immunoreactivity in the brainstem at 7 and 14 days but not 28 days compared with craniotomy‐only and controls, P < .001. CGRP levels in brainstem tissues were significantly increased in CCI groups compared with controls (incision‐only and naïve mice) or craniotomy‐only mice at each endpoint examined, P < .0001. There was a significant correlation between CGRP and periorbital allodynia (P < .0001, r = −0.65) but not for SP (r = 0.20). CCI significantly increased the number of macrophage/microglia in the injured cortex at each endpoint up to 28 days, although cell numbers declined over weeks post‐injury, P < .001. GFAP+ immunoreactivity was significantly increased at 7 but not 14 or 28 days after CCI, P < .001. Craniotomy resulted in transient periorbital allodynia accompanied by transient increases in SP, CGRP, and GFAP immunoreactivity compared with control mice. There was no increase in the number of macrophage/microglia cells compared with controls after craniotomy.Conclusion.— Injury to the somatosensory cortex results in persistent periorbital allodynia and increases in brainstem nociceptive neuropeptides. Findings suggest that persistent allodynia and increased neuropeptides are maintained by mechanisms other than activation of macrophage/microglia or astrocyte in the injured somatosensory cortex.
The Effectiveness of Repeat Celiac Plexus Neurolysis for Pancreatic Cancer: A Pilot Study
Authors: McGreevy Kai , Hurley Robert W. , Erdek Michael A. , Aner Musa M. , Li Sean , Cohen Steven P. 
Published: May 2012

AbstractBackground:  Celiac plexus neurolysis (CPN) is an effective but temporary management tool for pancreatic cancer pain (PCP). Clinical studies have shown the duration of benefit with initial CPN to be apaproximately 3 months. When pain recurs, CPN may be repeated, but the outcomes for repeat CPN are not well established. The objective of this study is to determine the success rate and duration of relief following repeat celiac plexus neurolysis (rCPN) for PCP.Methods:  Patients who underwent rCPN were identified from a database and their records reviewed. Responses of rCPN were then compared with iCPN for success rates and duration of relief. Success was defined as ≥ 50% pain relief lasting ≥ 1 month.Results:  Overall, there were 24 rCPN performed. The success rate decreased from 67% after initial CPN to 29% following rCPN (P = 0.13). The mean duration of pain relief decreased in parallel from 3.4 months (iCPN) to 1.6 months (rCPN) (P = 0.03). Among those who had a successful rCPN, 2.9 months elapsed from iCPN to rCPN, with disease progression noted in 29%. In those who failed rCPN, 7.8 months elapsed, with disease progression apapreciated in 71% of cases.Conclusions:  rCPN does not provide as much pain relief as iCPN. Disease progression as detailed on imaging appears to be a major factor in the limitations of rCPN. Further prospective studies are warranted to confirm these results and investigate the utility of rCPN.
Public Attitudes toward Climate Science and Climate Policy in Federal Systems: Canada and the United States Compared1
Authors: Lachapelle Erick , Borick Christopher P. , Rabe Barry 
Published: May 2012

AbstractMultilevel governance poses several challenges for the politics of climate change. On the one hand, the unequal distribution of power and interests can serve as a barrier to implementing coherent policy at a federal level. On the other, these features also enable policy leadership among sub‐federal units. In the context of wide variation in climate policy at both national and sub‐federal levels in Canada and in the United States, this paper utilizes an original data set to examine public attitudes and perceptions toward climate science and climate change policy in two federal systems. Drawing on national and provincial/state level data from telephone surveys administered in the United States and in Canada, the paper provides insight into where the public stands on the climate change issue in two of the most carbon‐intensive federal systems in the world. The paper includes the first directly comparable public opinion data on how Canadians and Americans form their opinions regarding climate matters and provides insight into the preferences of these two populations regarding climate policies at both the national and sub‐federal levels. Key findings are examined in the context of growing policy experiments at the sub‐federal level in both countries and limited national level progress in the adoption of climate change legislation.