Long-term nitrogen deposition increases phosphorus limitation of bryophytes in an ombrotrophic bog

Here we investigate the effect of 4 years simulated atmospheric deposition of ammonium (NH₄) and nitrate (NO₃), applied alone or in combination with phosphorus and potassium (PK), on the surface phosphatase activities and nutrient acquisition behaviour of two species of moss (Sphagnum capillifolium and Hypnum jutlandicum) from an ombrotrophic peatland. Phosphatase activity was significantly enhanced by both the NH₄ and NO₃ treatments, particularly for Sphagnum, but the activity decreased when exposed to additions of PK. Regression analysis revealed that phosphatase activity on Sphagnum was positively related with tissue N and negatively related to tissue P concentrations. For Hypnum, a negative relationship between shoot P concentration and phosphatase activity was observed. Using a ³²P tracer, mosses removed from plots receiving PK in combination with NH₄ maintained their affinity for increased phosphorus uptake. These findings suggest that enhanced nutrient supply, even at modest doses, significantly alter the nutrient recycling behaviour of bryophytes.     

Influence of related donor age on outcomes after peripheral blood stem cell transplantation

Background aimsThe rising use of allogeneic transplantation in older recipients necessitates considering older related donors. The effect of related donor age for peripheral blood stem cell allografts (PBSC) on graft maintenance and outcomes, independent of CD34⁺cell dose, has not been well-characterized.MethodsHLA-related donors (98% siblings) underwent a uniform filgrastim-based mobilization regimen aiming to collect and infuse 5 × 10⁶ CD34⁺ cells/recipient kg. Donor and recipient age were modeled in multiple ways to account for the correlation, and outcomes reported by decade of donor age.ResultsThe median donor and recipient ages were 52 years and 54 years, respectively. The mean CD34⁺ cell dose infused was 5.6 × 10⁶ CD34⁺/kg and 75% of patients received a narrow range between 4.4 and 6.6 × 10⁶ CD34⁺ cells/kg. Neither better PBSC mobilization nor higher CD34⁺ content of allografts was significantly associated with engraftment or transplant outcomes. After adjusting for recipient age and other prognostic factors, older donor age by decade conferred a lower risk of non-relapse mortality (NRM) [hazard ratio (HR) = 0.64, 95% confidence interval (CI) 0.45–0.91, P = 0.013] and borderline improvement in overall survival (OS) (HR = 0.76, 95% CI 0.58–0.99, P = 0.045) without altering progression-free survival (PFS) (HR = 0.85, 95% CI 0.66–1.07, P = 0.18).ConclusionsOlder donor age does not worsen outcome after matched related donor PBSC transplantation in patients receiving a narrow range CD34⁺ cells. The relatively small sample size mandates that the finding of similar to improved outcomes for older related donor age must be confirmed in larger studies.     

The design and synthesis of YC-1 analogues as probes for soluble guanylate cyclase

Soluble guanylate cyclase (sGC) is highly activated in the presence of both YC-1 (1-benzyl-3-(5'-hydroxymethyl-2'-furyl)-indazole) and CO. In this report, the design, synthesis, and activity (i.e., sGC activation) of photolabile analogues of 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole (YC-1) are presented. Initial results with 6-azido-3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole led to the synthesis of a tritium-labeled analogue. When photoactivated, this analogue labeled the alpha-subunit of sGC.     

Multiple, non-allelic, intein-coding sequences in eukaryotic RNA polymerase genes

Background  

Inteins are self-splicing protein elements. They are translated as inserts within host proteins that excise themselves and ligate the flanking portions of the host protein (exteins) with a peptide bond. They are encoded as in-frame insertions within the genes for the host proteins. Inteins are found in all three domains of life and in viruses, but have a very sporadic distribution. Only a small number of intein coding sequences have been identified in eukaryotic nuclear genes, and all of these are from ascomycete or basidiomycete fungi.