An efficient method for regeneration of lavandin (Lavandula x intermedia cv. 'Grosso')

An efficient protocol for the regeneration of lavandin (Lavandula x intermedia cv. 'Grosso') is reported. Thiadazuron (9 μM), a plant growth-modulating phenylurea, was used to induce callus formation and shoot initiation from cultured leaf explants. Newly emerged shoots were maintained on media containing 0.05 μM naphthaleneacetic acid to allow maturation, and then transferred to media containing 2.9 μM indole-3-acetic acid to allow root formation. The phenolic control agents polyvinylpyrrolidone (PVP), ascorbic acid, 2-aminoindane-2-phosphonic acid, and activated charcoal were tested for their ability to prevent shoot browning and death in culture. All agents except PVP were found to be effective, with ascorbic acid being most consistent in promoting development of healthy mature shoots. The effect of light type (red light vs. white light) and culture medium composition (full- and half-strength Murashige and Skoog or Llyod and McCown’s woody plant medium (WPM)) on rooting efficiency was also evaluated. Cultures on half-strength WPM in white light were found to have the highest rooting efficiency. Additionally, application of the polyamines putrescine, spermine, and spermidine were tested for their effect on rooting. While rooting efficiency was not improved with any of the treatments, spermine and spermidine were found to have an inhibitory effect at concentrations greater than 10 μM.     

Hepatic mitochondrial dysfunction in Friedreich Ataxia

Background  

Mitochondrial dysfunction due to respiratory chain impairment is a key feature in pathogenesis of Friedreich ataxia. Friedreich ataxia affects the nervous system, heart and pancreas.     

Drying–Rewetting Cycles Affect Fungal and Bacterial Growth Differently in an Arable Soil

Drying and rewetting is a frequent physiological stress for soil microbial communities; a stress that is predicted to grow more influential with future climate change. We investigated the effect of repeated drying–rewetting cycles on bacterial (leucine incorporation) and fungal (acetate in ergosterol incorporation) growth, on the biomass concentration and composition (PLFA), and on the soil respiration. Using different plant material amendments, we generated soils with different initial fungal:bacterial compositions that we exposed to 6–10 repetitions of a drying–rewetting cycle. Drying–rewetting decreased bacterial growth while fungal growth remained unaffected, resulting in an elevated fungal:bacterial growth ratio. This effect was found irrespective of the initial fungal:bacterial biomass ratio. Many drying–rewetting cycles did not, however, affect the fungal:bacterial growth ratio compared to few cycles. The biomass response of the microbial community differed from the growth response, with fungal and total biomass only being slightly negatively affected by the repeated drying–rewetting. The discrepancy between growth- and biomass-based assessments underscores that microbial responses to perturbations might previously have been misrepresented with biomass-based assessments. In light of this, many aspects of environmental microbial ecology may need to be revisited with attention to what measure of the microbial community is relevant to study.     

Leaf rust (Puccinia triticina) resistance in wheat (Triticum aestivum) cultivars grown in Northern Europe 1992-2002

Diversity of resistance to leaf rust caused by Puccinia triticina can be enhanced in wheat (Triticum aestivum) cultivars through a better knowledge of resistance genes that are present in important cultivars and germplasm. Multi-pathotype tests on 84 wheat cultivars grown in Denmark, Finland, Norway and Sweden during 1992-2002 and 39 differential testers enabled the postulation of nine known genes for seedling resistance to leaf rust. Genes Lr1, Lr2a, Lr3, Lr10, Lr13, Lr14a, Lr17, Lr23 and Lr26 were found singly or in combination in 47 of the cultivars (55.9%). The most frequently occurring genes in cultivars grown in Sweden were Lr13 (20.4%), Lr14a (14.8%) and Lr26 (14.8%). Lr14a was the most common gene in cultivars grown in Norway (18.7%), Lr13 in Denmark (35.5%) and Lr10 in Finland (20.0%). Although 28 cultivars (33.3%) exhibited a response pattern that could not be assigned to resistance genes or combinations present in the tester lines, several pathotypes carried virulence and hence these genes or combinations are of limited use. Nine cultivars (10.7%) lacked detectable seedling resistance. One cultivar was resistant to all pathotypes used in the study.     

Impaired TNFα-induced VEGF Expression in Human Airway Smooth Muscle Cells from Smokers with COPD: Role of MAPkinases and Histone Acetylation—Effect of Dexamethasone

The cytokine and potent angiogenic factor vascular endothelial growth factor (VEGF) plays an important role in airway remodelling in various airway diseases such as idiopathic pulmonary fibrosis, pulmonary hypertension, lung cancer, asthma and chronic obstructive pulmonary disease (COPD). The effect of cigarette-smoking on VEGF expression, the modulatory role of extracellular signal-regulated kinase (ERK)-1,-2, p38mitogen-activated protein kinase (MAPK), histone acetylation and the anti-inflammatory effect of dexamethasone on TNFα-induced VEGF expression were examined in human airway smooth muscle cells (HASMC) of five non-smokers, 17 smokers without airflow limitation and 15 smokers with COPD. TNFα increased VEGF expression 5.4-fold and 4.0-fold in HASMC from non-smokers and smokers without airflow limitation, respectively, but only 2.5-fold in HASMC from smokers with COPD compared with non-stimulated HASMC. VEGF production was dependent on phosphorylation of ERK-1,-2 and p38^MAPK, as was shown by examining the effects of PD 098059 (10 μM), an inhibitor of the upstream activator of MAPKkinase (MKK)-1, and SB 203580 (10 μM), an inhibitor of p38^MAPK; there were no differences between non-smokers, smokers without airflow limitation and smokers with COPD in this respect. Dexamethasone (DEX; 10⁻¹²–10⁻⁴ M) reduced TNFα-induced phosphorylation of ERK-1/-2 and prevented TNFα-induced VEGF generation without differences between non-smokers, smokers with and without COPD. There was an additional inhibitory effect of DEX (10⁻¹² M) on VEGF-release when PD 098059 was added. The basal and TNFα-induced acetylation status of the VEGF-promoter (chromatin immunoprecipitation [ChIP] assay) was increased in HASMC from smokers with COPD compared with smokers without airflow limitation and non-smokers. In comparison to non-stimulated HASMC, TNFα decreased the acetylation status of the VEGF-promoter by ∼46% and ∼43% in HASMC from non-smokers and smokers without COPD compared with ∼68% in HASMC from smokers with COPD. The data suggest that HASMC express VEGF in response to TNFα and that this may be reduced in HASMC of smokers with COPD in a smoking-independent manner. VEGF expression is directly modulated by phosphorylation of ERK-1,-2 and p38^MAPK and by histone acetylation and the acetylation status of the VEGF gene is increased in HASMC of smokers with COPD in a smoking-independent manner. TNFα reduced the acetylation status of the VEGF promoter in HASMC.     

Adaptation of soil microbial growth to temperature: Using a tropical elevation gradient to predict future changes

Terrestrial biogeochemical feedbacks to the climate are strongly modulated by the temperature response of soil microorganisms. Tropical forests, in particular, exert a major influence on global climate because they are the most productive terrestrial ecosystem. We used an elevation gradient across tropical forest in the Andes (a gradient of 20°C mean annual temperature, MAT), to test whether soil bacterial and fungal community growth responses are adapted to long‐term temperature differences. We evaluated the temperature dependency of soil bacterial and fungal growth using the leucine‐ and acetate‐incorporation methods, respectively, and determined indices for the temperature response of growth: Q₁₀ (temperature sensitivity over a given 10oC range) and T_min (the minimum temperature for growth). For both bacterial and fungal communities, increased MAT (decreased elevation) resulted in increases in Q₁₀ and T_min of growth. Across a MAT range from 6°C to 26°C, the Q₁₀ and T_min varied for bacterial growth (Q_10–20 = 2.4 to 3.5; T_min = ?8°C to ?1.5°C) and fungal growth (Q_10–20 = 2.6 to 3.6; T_min = ?6°C to ?1°C). Thus, bacteria and fungi did not differ significantly in their growth temperature responses with changes in MAT. Our findings indicate that across natural temperature gradients, each increase in MAT by 1°C results in increases in T_min of microbial growth by approximately 0.3°C and Q_10–20 by 0.05, consistent with long‐term temperature adaptation of soil microbial communities. A 2°C warming would increase microbial activity across a MAT gradient of 6°C to 26°C by 28% to 15%, respectively, and temperature adaptation of microbial communities would further increase activity by 1.2% to 0.3%. The impact of warming on microbial activity, and the related impact on soil carbon cycling, is thus greater in regions with lower MAT. These results can be used to predict future changes in the temperature response of microbial activity over different levels of warming and over large temperature ranges, extending to tropical regions.     

Nitrogen Isotope Patterns in Alaskan Black Spruce Reflect Organic Nitrogen Sources and the Activity of Ectomycorrhizal Fungi

Global patterns in soil, plant, and fungal stable isotopes of N (δ¹⁵N) show promise as integrated metrics of N cycling, particularly the activity of ectomycorrhizal (ECM) fungi. At small spatial scales, however, it remains difficult to differentiate the underlying causes of plant δ¹⁵N variability and this limits the application of such measurements to better understand N cycling. We conducted a landscape-scale analysis of δ¹⁵N values from 31 putatively N-limited monospecific black spruce (Picea mariana) stands in central Alaska to assess the two main hypothesized sources of plant δ¹⁵N variation: differing sources and ECM fractionation. We found roughly 20% of the variability in black spruce foliar N and δ¹⁵N values to be correlated with the concentration and δ¹⁵N values of soil NH₄ ⁺ and dissolved organic N (DON) pools, respectively. However, ¹⁵N-based mixing models from 24 of the stands suggested that fractionation by ECM fungi obscures the ¹⁵N signature of soil N pools. Models, regressions, and N abundance data all suggested that increasing dependence on soil DON to meet black spruce growth demands predicates increasing reliance on ECM-derived N and that black spruce, on average, received 53% of its N from ECM fungi. Future research should partition the δ¹⁵N values within the soil DON pool to determine how choice of soil δ¹⁵N values influence modeled ECM activity. The C balance of boreal forests is tightly linked to N cycling and δ¹⁵N values may be useful metrics of changes to these connections.     

Impact of Rescue-Thrombolysis during Cardiopulmonary Resuscitation in Patients with Pulmonary Embolism

Background

Cardiac arrest in patients with pulmonary embolism (PE) is associated with high morbidity and mortality. Thrombolysis is expected to improve the outcome in these patients. However studies evaluating rescue-thrombolysis in patients with PE are missing, mainly due to the difficulties of clinical diagnosis of PE. We aimed to determine the success influencing factors of thrombolysis during resuscitation in patients with PE.

Methodology/Principal Findings

We analyzed retrospectively the outcome of 104 consecutive patients with confirmed (n = 63) or highly suspected (n = 41) PE and monitored cardiac arrest. In all patients rtPA was administrated for thrombolysis during cardiopulmonary resuscitation. In 40 of the 104 patients (38.5%) a return of spontaneous circulation (ROSC) could be achieved successfully. Patients with ROSC received thrombolysis significantly earlier after CPR onset compared to patients without ROSC (13.6±1.2 min versus 24.6±0.8 min; p<0.001). 19 patients (47.5%) out of the 40 patients with initially successful resuscitation survived to hospital discharge. In patients with hospital discharge thrombolysis therapy was begun with a significantly shorter delay after cardiac arrest compared to all other patients (11.0±1.3 vs. 22.5±0.9 min; p<0.001).

Conclusion

Rescue-thrombolysis should be considered and started in patients with PE and cardiac arrest, as soon as possible after cardiac arrest onset.