Azacitidine for treatment of imminent relapse in MDS or AML patients after allogeneic HSCT: results of the RELAZA trial

This study evaluated azacitidine as treatment of minimal residual disease (MRD) determined by a sensitive donor chimerism analysis of CD34+ blood cells to pre-empt relapse in patients with CD34+ myelodysplastic syndromes (MDS) or acute myeloid leukemia (AML) after allogeneic hematopoietic stem cell transplantation (HSCT). At a median of 169 days after HSCT, 20/59 prospectively screened patients experienced a decrease of CD34+ donor chimerism to <80% and received four azacitidine cycles (75 mg/m2/day for 7 days) while in complete hematologic remission. A total of 16 patients (80%) responded with either increasing CD34+ donor chimerism to ⩾80% (n=10; 50%) or stabilization (n=6; 30%) in the absence of relapse. Stabilized patients and those with a later drop of CD34+ donor chimerism to <80% after initial response were eligible for subsequent azacitidine cycles. A total of 11 patients (55%) received a median of 4 (range, 1–11) additional cycles. Eventually, hematologic relapse occurred in 13 patients (65%), but was delayed until a median of 231 days (range, 56–558) after initial decrease of CD34+ donor chimerism to <80%. In conclusion, pre-emptive azacitidine treatment has an acceptable safety profile and can substantially prevent or delay hematologic relapse in patients with MDS or AML and MRD after allogeneic HSCT

Exact model reduction of combinatorial reaction networks

Receptors and scaffold proteins usually possess a high number of distinct binding domains inducing the formation of large multiprotein signaling complexes. Due to combinatorial reasons the number of distinguishable species grows exponentially with the number of binding domains and can easily reach several millions. Even by including only a limited number of components and binding domains the resulting models are very large and hardly manageable. A novel model reduction technique allows the significant reduction and modularization of these models

Phosphorus dynamics in a tropical forest soil restored after strip mining

Background and aims We hypothesized that successful early ecosystem and soil development in these P-deficient soil materials will initially depend on effective re-establishment of P storage and cycling through organic matter. This hypothesis was tested in a 26-year chronosequence of seven lightly fertilized, oxidic soil materials restored to eucalypt forest communities after bauxite mining. Methods Total P (Pt) status, Hedley P fractions and partial chemical speciation (NaOH-EDTA extraction and analysed using solution 31P NMR spectroscopy) were determined in the restored soils. Results Concentrations of Pt and most Hedley fractions changed with restoration period, declined with depth and were strongly positively correlated with C and N concentrations. Biological P dominated the Labile and Intermediate P fractions while Long-term P was dominantly inorganic. Organic P concentrations in NaOH-EDTA extracts and their chemical natures were similar in restored and unburned native forest sites. Phosphomonoesters were the dominant class of organic P. Conclusions Surprisingly rapid P accretion and fractional changes occurred over 26 years, largely in the surface soils and closely associated with organic matter status. Alkaline hydrolysis products of phosphodiesters and pyrophosphate indicated the importance of microbial P cycling. The important consequences for long-term ecosystem development and biological diversity require further study

What Do We Know About Neuropsychological Aspects Of Schizophrenia?

Application of a neuropsychological perspective to the study of schizophrenia has established a number of important facts about this disorder. Some of the key findings from the existing literature are that, while neurocognitive impairment is present in most, if not all, persons with schizophrenia, there is both substantial interpatient heterogeneity and remarkable within-patient stability of cognitive function over the long-term course of the illness. Such findings have contributed to the firm establishment of neurobiologic models of schizophrenia, and thereby help to reduce the social stigma that was sometimes associated with purely psychogenic models popular during parts of the 20th century. Neuropsychological studies in recent decades have established the primacy of cognitive functions over psychopathologic symptoms as determinants of functional capacity and independence in everyday functioning. Although the cognitive benefits of both conventional and even second generation antipsychotic medications appear marginal at best, recognition of the primacy of cognitive deficits as determinants of functional disability in schizophrenia has catalyzed recent efforts to develop targeted treatments for the cognitive deficits of this disorder. Despite these accomplishments, however, some issues remain to be resolved. Efforts to firmly establish the specific neurocognitive/neuropathologic systems responsible for schizophrenia remain elusive, as do efforts to definitively demonstrate the specific cognitive deficits underlying specific forms of functional impairment. Further progress may be fostered by recent initiatives to integrate neuropsychological studies with experimental neuroscience, perhaps leading to measures of deficits in cognitive processes more clearly associated with specific, identifiable brain systems