| 1. |
- Degenkolbe, Thomas, et al.
(författare)
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Expression profiling of rice cultivars differing in their tolerance to long-term drought stress
- 2009
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Ingår i: Plant Molecular Biology. - Dordrecht, Netherlands : Springer. - 0167-4412 .- 1573-5028. ; 69:1-2, s. 133-53
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the molecular basis of plant performance under water-limiting conditions will help to breed crop plants with a lower water demand. We investigated the physiological and gene expression response of drought-tolerant (IR57311 and LC-93-4) and drought-sensitive (Nipponbare and Taipei 309) rice (Oryza sativa L.) cultivars to 18 days of drought stress in climate chamber experiments. Drought stressed plants grew significantly slower than the controls. Gene expression profiles were measured in leaf samples with the 20 K NSF oligonucleotide microarray. A linear model was fitted to the data to identify genes that were significantly regulated under drought stress. In all drought stressed cultivars, 245 genes were significantly repressed and 413 genes induced. Genes differing in their expression pattern under drought stress between tolerant and sensitive cultivars were identified by the genotype x environment (G x E) interaction term. More genes were significantly drought regulated in the sensitive than in the tolerant cultivars. Localizing all expressed genes on the rice genome map, we checked which genes with a significant G x E interaction co-localized with published quantitative trait loci regions for drought tolerance. These genes are more likely to be important for drought tolerance in an agricultural environment. To identify the metabolic processes with a significant G x E effect, we adapted the analysis software MapMan for rice. We found a drought stress induced shift toward senescence related degradation processes that was more pronounced in the sensitive than in the tolerant cultivars. In spite of higher growth rates and water use, more photosynthesis related genes were down-regulated in the tolerant than in the sensitive cultivars.
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| 2. |
- Johansson, Jan, et al.
(författare)
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Impact of Proton Pump Inhibitors on Benign Anastomotic Stricture Formations After Esophagectomy and Gastric Tube Reconstruction: Results From a Randomized Clinical Trial.
- 2009
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Ingår i: Annals of Surgery. - 1528-1140.
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE:: The primary aim of this study was to evaluate if the use of proton pump inhibitors (PPIs) reduced the prevalence of benign anastomotic strictures after uncomplicated esophagectomies with gastric tube reconstruction and circular stapled anastomoses. SUMMARY BACKGROUND DATA:: Benign anastomotic strictures are associated with anastomotic leaks or conduit ischemia. Also patients without those complications develop benign anastomotic strictures. We hypothesize that patients without postoperative anastomotic complications may develop benign anastomotic strictures due to exposure of acid gastric tube contents to the anastomotic area, and that the formation of such strictures may be reduced by prophylactic use of PPIs. METHODS:: Eighty patients without preoperative chemo- or radiotherapy, without clinical or radiological signs of anastomotic leaks were included in this clinical trial. The patients were randomized to b.i.d. PPIs or no treatment for 1 year. Benign anastomotic strictures were defined as anastomotic narrowing not allowing a standard diagnostic endoscope to pass without dilatation. The study was registered in the EudraCT database (2009-009997-28) for clinical trials. RESULTS:: Seventy-nine patients were evaluated. Benign anastomotic strictures developed in 5/39 (13%) patients in the PPI group and in 18/40 (45%) in the control group (RR 5.6, 95% CI: 2.0-15.9, P = 0.001). The use of a narrower 25 mm cartridge as compared to a wider 28 or 31 mm cartridge significantly increased stricture formations (RR 2.9, 95% CI: 1.1-7.6, P = 0.025). CONCLUSIONS:: Prophylactic PPI treatment reduced the prevalence of benign anastomotic strictures following esophagectomy with gastric tube reconstruction and circular stapled anastomoses. Larger sized circular staple cartridges additionally reduced the stricture prevalence.
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| 3. |
- Johansson, Jan, et al.
(författare)
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Two Different Surgical Approaches in the Treatment of Adenocarcinoma at the Gastroesophageal Junction.
- 2008
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Ingår i: World Journal of Surgery. - : Springer Science and Business Media LLC. - 1432-2323 .- 0364-2313. ; 32, s. 1013-1020
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Adenocarcinoma at the gastroesophageal junction may be regarded as of esophageal or of gastric origin, and tumor removal may follow the principles of esophagectomy or extended gastrectomy. We determined the impact of this strategy on our patients with tumors at this site. METHODS: Baseline patient and tumor characteristics were collected, and tumors were categorized according to Siewert's classification (I, II, or III) of gastroesophageal junction tumors. Totally, 133 patients were operated on between 1990 and 2001. Ninety-six patients with type I (n = 67), II (n = 26), and III (n = 3) tumors underwent esophagectomy and gastric tube reconstruction, and 37 patients with type I (n = 5), II (n = 26), and III (n = 6) tumors underwent extended gastrectomy and long Roux-en-Y reconstructions. RESULTS: After adjusting for the independently significant impact factors-tumor stage, tumor dissection (R0-R2), and length of tumor free resection margins-we did not find any specific survival benefit associated with either of the two evaluated surgical approaches for tumor resection and reconstruction. The EORTC quality of life forms revealed good results as indicated by the functional scales and the symptom scales. CONCLUSIONS: Provided that adequate tumor dissection is performed, patients with adenocarcinoma at the gastroesophageal junction can be resected and reconstructed using the principles for esophagectomy or extended gastrectomy.
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| 4. |
- Kozian, Alf, 1969-
(författare)
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Pathophysiological and Histomorphological Effects of One-Lung Ventilation in the Porcine Lung
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Thoracic surgical procedures require partial or complete airway separation and the opportunity to exclude one lung from ventilation (one-lung ventilation, OLV). OLV is commonly associated with profound pathophysiological changes that may affect the postoperative outcome. It is injurious in terms of increased mechanical stress including alveolar cell stretch and overdistension, shear forces secondary to repeated tidal collapse and reopening of alveolar units and compression of alveolar vessels. Ventilation and perfusion distribution may thus be affected during and after OLV. The present studies investigated the influence of OLV on ventilation and perfusion distribution, on the gas/tissue distribution and on the lung histomorphology in a pig model of thoracic surgery.Anaesthetised and mechanically ventilated piglets were examined. The ventilation and perfusion distribution within the lungs was assessed by single photon emission computed tomography. Computed tomography was used to establish the effects of OLV on dependent lung gas/tissue distribution. The pulmonary histopathology of pigs undergoing OLV and thoracic surgery was compared with that of two-lung ventilation (TLV) and spontaneous breathing.OLV induced hyperperfusion and significant V/Q mismatch in the ventilated lung persistent in the postoperative course. It increased cyclic tidal recruitment that was associated with a persistent increase of gas content in the ventilated lung. OLV and thoracic surgery as well resulted in alveolar damage. In the present model of OLV and thoracic surgery, alveolar recruitment manoeuvre (ARM) and protective ventilation approach using low tidal volume preserved the ventilated lung density distribution and did not aggravate cyclic recruitment of alveoli in the ventilated lung.In conclusion, the present model established significant alveolar damage in response to OLV and thoracic surgery. Lung injury could be related to the profound pathophysiological consequences of OLV including hyperperfusion, ventilation/perfusion mismatch and increased tidal recruitment of lung tissue in the dependent, ventilated lung. These mechanisms may contribute to the increased susceptibility for respiratory complications in patients undergoing thoracic surgery. A protective approach including sufficient ARM, application of PEEP, and the use of lower tidal volumes may prevent the ventilated lung from deleterious consequences of OLV.
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| 7. |
- Tehua Lu, Timothy, et al.
(författare)
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An evaluation of the genetic-matched pair study design using genome-wide SNP data from the European population
- 2009
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Ingår i: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 17:7, s. 967-975
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Tidskriftsartikel (refereegranskat)abstract
- Genetic matching potentially provides a means to alleviate the effects of incomplete Mendelian randomization in population-based gene-disease association studies. We therefore evaluated the genetic-matched pair study design on the basis of genome-wide SNP data (309 790 markers; Affymetrix GeneChip Human Mapping 500K Array) from 2457 individuals, sampled at 23 different recruitment sites across Europe. Using pair-wise identity-by-state (IBS) as a matching criterion, we tried to derive a subset of markers that would allow identification of the best overall matching (BOM) partner for a given individual, based on the IBS status for the subset alone. However, our results suggest that, by following this approach, the prediction accuracy is only notably improved by the first 20 markers selected, and increases proportionally to the marker number thereafter. Furthermore, in a considerable proportion of cases (76.0%), the BOM of a given individual, based on the complete marker set, came from a different recruitment site than the individual itself. A second marker set, specifically selected for ancestry sensitivity using singular value decomposition, performed even more poorly and was no more capable of predicting the BOM than randomly chosen subsets. This leads us to conclude that, at least in Europe, the utility of the genetic-matched pair study design depends critically on the availability of comprehensive genotype information for both cases and controls. European Journal of Human Genetics (2009) 17, 967-975; doi:10.1038/ejhg.2008.266; published online 21 January 2009
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| 9. |
- Walther, Gian-Reto, et al.
(författare)
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Alien species in a warmer world: risks and opportunities
- 2009
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Ingår i: Trends in Ecology & Evolution. - : Elsevier BV. - 1872-8383 .- 0169-5347. ; 24:12, s. 686-693
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Forskningsöversikt (refereegranskat)abstract
- Climate change and biological invasions are key processes affecting global biodiversity, yet their effects have usually been considered separately. Here, we emphasise that global warming has enabled alien species to expand into regions in which they previously could not survive and reproduce. Based on a review of climate-mediated biological invasions of plants, invertebrates, fishes and birds, we discuss the ways in which climate change influences biological invasions. We emphasise the role of alien species in a more dynamic context of shifting species' ranges and changing communities. Under these circumstances, management practices regarding the occurrence of 'new' species could range from complete eradication to tolerance and even consideration of the 'new' species as an enrichment of local biodiversity and key elements to maintain ecosystem services.
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| 10. |
- Walther, G.R., et al.
(författare)
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Palms tracking climate change
- 2007
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Ingår i: Global Ecology and Biogeography. - : Wiley. - 1466-8238 .- 1466-822X. ; 16, s. 801-809
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Tidskriftsartikel (refereegranskat)abstract
- Aim Many species are currently expanding their ranges in response to climate change, but the mechanisms underlying these range expansions are in many cases poorly understood. In this paper we explore potential climatic factors governing the recent establishment of new palm populations far to the north of any other viable palm population in the world. Location Southern Switzerland, Europe, Asia and the world. Methods We identified ecological threshold values for the target species, Trachycarpus fortunei, based on gridded climate data, altitude and distributional records from the native range and applied them to the introduced range using local field monitoring and measured meteorological data as well as a bioclimatic model. Results We identified a strong relationship between minimum winter temperatures, influenced by growing season length and the distribution of the palm in its native range. Recent climate change strongly coincides with the palm's recent spread into southern Switzerland, which is in concert with the expansion of the global range of palms across various continents. Main conclusions Our results strongly suggest that the expansion of palms into (semi-)natural forests is driven by changes in winter temperature and growing season length and not by delayed population expansion. This implies that this rapid expansion is likely to continue in the future under a warming climate. Palms in general, and T. fortunei in particular, are significant bioindicators across continents for present-day climate change and reflect a global signal towards warmer conditions.
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