A new approach to quantify visceral fat via bioelectrical impedance analysis and ultrasound compared to MRI.

BACKGROUND: Visceral adipose tissue (VAT) has been linked to systemic proinflammatory characteristics, and measuring it accurately usually requires sophisticated instruments. This study aimed to estimate VAT applying a simpler method that uses total subcutaneous fat and total body fat (BF) measurements. METHOD: As part of our experimental approach, the subcutaneous fat mass (SFT) was measured via US (SFTtotal), and VAT was quantified by assessing MRI data. Both parameters were added to obtain total body fat (BFcalc). Those results were then compared to values obtained from a bioelectrical impedance analysis (BFBIA). Multiple regression analyses were employed to develop a simplified sex-specific equation for SFT, which was subsequently used in conjunction with BFBIA to determine VAT (VATEq). RESULT: We observed excellent reliability between BFBIA and BFcalc, with no significant difference in body fat values (20.98 ± 8.36 kg vs. 21.08 ± 8.81 kg, p = 0.798, ICC 0.948). VATEq_female/male revealed excellent reliability when compared to VATMRI, and no significant difference appeared (women: 0.03 ± 0.66 kg with a 95% CI ranging from -1.26 kg to 1.32 kg, p = 0.815, ICC: 0.955.; men: -0.01 ± 0.85 kg with a 95% CI ranging from -1.69 kg to 1.66 kg, p = 0.925, ICC: 0.952). CONCLUSION: Taking an experimental approach, VAT can be determined without MRI.

Measurement of subcutaneous fat tissue: reliability and comparison of caliper and ultrasound via systematic body mapping.

Caliper and ultrasound (US) are used to measure subcutaneous fat tissue depth (SFT) and then to calculate total body fat. There is no evidence-based recommendation as to whether caliper or US are equally accurate. The aim of this paper was therefore to compare reliability of both methods. In this methodical study, 54 participants (BMI: 24.8 ± 3.5 kg/m2; Age: 43.2 ± 21.7 years) were included. Using systematic body mapping, the SFT of 56 areas was measured. We also analyzed 4 body sites via MRI. A comparison between caliper and US detected clear differences in mean SFT of all areas (0.83 ± 0.33 cm vs. 1.14 ± 0.54 cm; p < 0.001) showing moderate reliability (ICC 0.669, 95%CI: 0.625-0.712). US and MRI revealed in the abdominal area a SFT twice as thick as caliper (2.43 ± 1.36 cm vs. 2.26 ± 1.32 cm vs. 1.15 ± 0.66 cm; respectively). Caliper and US revealed excellent intrarater (ICC caliper: 0.944, 95%CI: 0.926-0.963; US: 0.934, 95%CI: 0.924-0.944) and good interrater reliability (ICC caliper: 0.794, 95%CI: 0.754-0.835; US: 0.825, 95%CI: 0.794-0.857). Despite the high reliability in measuring SFT that caliper and US show, our comparison of the two methods yielded clear differences in SFT, particularly in the abdominal area. In accuracy terms, US is preferable for most mapping areas.

[Laboratory study on bacteriological aspects of beverages and thickeners for dysphagia patients : Growth survey of Escherichia coli on thickeners and beverages]. / Laborstudie zu bakteriologischen Aspekten von Getränken und Andickungsmitteln für Dysphagiepatienten : Wachstumserhebung von Escherichia coli auf Andickungsmitteln und Getränken.

BACKGROUND: Currently, there is little evidence-based guidance on bacteriological aspects of thickeners or beverages for dysphagia patients in Germany that can be recommended to prevent aspiration pneumonia. Therefore, the aim of this study was to evaluate the lowest cell amount of E. coli on M9 agar media with beverages and thickeners. METHODOLOGY: In the laboratory experiment 1 · 107 cells of E. coli were plated on a defined minimal medium (M9 agar plates) with different carbon sources and incubated at 37 °C for 2 days. The increase in cell number was determined using a photometer. Carbon sources were water, beer, orange juice, thickened beer, maltodextrin-xanthan gum-based thickeners, corn starch-based thickeners and potato starch-based thickeners. RESULTS: The lowest E. coli cell amount was measured on water compared to beer, orange juice and all thickeners. A higher E. coli cell count was measured on maltodextrin-based thickeners than on potato starch-based and corn starch-based thickeners. DISCUSSION: In the present laboratory experiment, no individual risk factors for the development of aspiration pneumonia in humans were considered; however, initial bacteriological evidence for dysphagia patients could be collected. Due to the high growth of E. coli on maltodextrin, yeast, fructose and glucose, these ingredients should be used with caution by dysphagia patients. Further research on thickeners and beverages is needed to make a comprehensive recommendation for action in this aspect.

Novel Intraoperative Imaging of Gastric Tube Perfusion during Oncologic Esophagectomy-A Pilot Study Comparing Hyperspectral Imaging (HSI) and Fluorescence Imaging (FI) with Indocyanine Green (ICG).

BACKGROUND: Novel intraoperative imaging techniques, namely, hyperspectral (HSI) and fluorescence imaging (FI), are promising with respect to reducing severe postoperative complications, thus increasing patient safety. Both tools have already been used to evaluate perfusion of the gastric conduit after esophagectomy and before anastomosis. To our knowledge, this is the first study evaluating both modalities simultaneously during esophagectomy. METHODS: In our pilot study, 13 patients, who underwent Ivor Lewis esophagectomy and gastric conduit reconstruction, were analyzed prospectively. HSI and FI were recorded before establishing the anastomosis in order to determine its optimum position. RESULTS: No anastomotic leak occurred during this pilot study. In five patients, the imaging methods resulted in a more peripheral adaptation of the anastomosis. There were no significant differences between the two imaging tools, and no adverse events due to the imaging methods or indocyanine green (ICG) injection occurred. CONCLUSIONS: Simultaneous intraoperative application of both modalities was feasible and not time consuming. They are complementary with regard to the ideal anastomotic position and may contribute to better surgical outcomes. The impact of their simultaneous application will be proven in consecutive prospective trials with a large patient cohort.

High sensitivity and clonal stability of the genomic fusion as single marker for response monitoring in ETV6-RUNX1-positive acute lymphoblastic leukemia.

BACKGROUND: Assessment of minimal residual disease (MRD) is an integral component for response monitoring and treatment stratification in acute lymphoblastic leukemia (ALL). We aimed to evaluate the genomic ETV6-RUNX1 fusion sites as a single marker for MRD quantification. PROCEDURE: In a representative, uniformly treated cohort of pediatric relapsed ALL patients (n = 52), ETV6-RUNX1 fusion sites were compared to the current gold standard, immunoglobulin/T-cell receptor (Ig/TCR) gene rearrangements. RESULTS: Primer/probe sets designed to ETV6-RUNX1 fusions achieved significantly more frequent a sensitivity and a quantitative range of at least 10-4 compared to the gold standard with 100% and 73% versus 76% and 47%, respectively. The breakpoint sequence was identical at diagnosis and relapse in all tested cases. There was a high degree of concordance between quantitative MRD results assessed using ETV6-RUNX1 and the highest Ig/TCR marker (Spearman's 0.899, P < .01) with differences >½ log-step in only 6% of patients. A high proportion of ETV6-RUNX1-positive ALL relapses (40%) in our cohort showed a poor response to induction treatment at relapse, and therefore had an indication for hematopoietic stem cell transplantation, demonstrating the need of accurate identification of this subgroup. CONCLUSIONS: ETV6-RUNX1 fusion sites are highly sensitive and reliable MRD markers. Our data confirm that they are unaffected by clonal evolution and selection during front-line and second-line chemotherapy in contrast to Ig/TCR rearrangements, which require several markers per patient to compensate for the observed loss of target clones. In future studies, the genomic ETV6-RUNX1 fusion can be used as single MRD marker.

Actionable, long-term stable and semantic web compatible identifiers for access to biological collection objects.

With biodiversity research activities being increasingly shifted to the web, the need for a system of persistent and stable identifiers for physical collection objects becomes increasingly pressing. The Consortium of European Taxonomic Facilities agreed on a common system of HTTP-URI-based stable identifiers which is now rolled out to its member organizations. The system follows Linked Open Data principles and implements redirection mechanisms to human-readable and machine-readable representations of specimens facilitating seamless integration into the growing semantic web. The implementation of stable identifiers across collection organizations is supported with open source provider software scripts, best practices documentations and recommendations for RDF metadata elements facilitating harmonized access to collection information in web portals. Database URL: : http://cetaf.org/cetaf-stable-identifiers.

Markerless Gene Deletion with Cytosine Deaminase in Thermus thermophilus Strain HB27.

We developed a counterselectable deletion system for Thermus thermophilus HB27 based on cytosine deaminase (encoded by codA) from Thermaerobacter marianensis DSM 12885 and the sensitivity of T. thermophilus HB27 to the antimetabolite 5-fluorocytosine (5-FC). The deletion vector comprises the pUC18 origin of replication, a thermostable kanamycin resistance marker functional in T. thermophilus HB27, and codA under the control of a constitutive putative trehalose promoter from T. thermophilus HB27. The functionality of the system was demonstrated by deletion of the bglT gene, encoding a ß-glycosidase, and three carotenoid biosynthesis genes, CYP175A1, crtY, and crtI, from the genome of T. thermophilus HB27.

Checklist of Recent thecideoid brachiopods from the Indian Ocean and Red Sea, with a description of a new species of Thecidellina from Europa Island and a re-description of T. blochmanni Dall from Christmas Island.

Compilation of a checklist of Recent thecideoid brachiopods from the Indian Ocean and Red Sea indicates that members of this superfamily are represented by a small number of species. The subfamily Lacazellinae is represented by Ospreyella maldiviana from the Maldive Islands but the presence of Lacazella cannot yet be confirmed in the Indian Ocean as the holotype of Lacazella mauritiana from Mauritius is lost. The subfamily Thecidellininae is represented by Thecidellina blochmanni from Christmas Island in the eastern Indian Ocean and the Red Sea while a new species T. europa is here described from Europa Island in the Mozambique Channel. The subfamily Minutellinae is represented by Minutella minuta from Samper Bank and Walters Bank in the south-western Indian Ocean and in the Red Sea. Since the holotype of Thecidellina blochmanni from Flying Fish Cove, Christmas Island is also lost, this species is re-described and illustrated mainly from topotypes in the Museum für Naturkunde, Berlin, from which a suggested neotype has been selected.

In Absentia: An Exploratory Study of How Patients Are Considered in Multidisciplinary Cancer Team Meetings.

BACKGROUND: Multidisciplinary team meetings and shared decision-making are potential means of delivering patient-centred care. Not much is known about how those two paradigms fit together in cancer care. This study aimed to investigate how decisions are made in multidisciplinary team meetings and whether patient perspectives are incorporated in these decisions. MATERIALS AND METHODS: A qualitative study was conducted using non-participant observation at multidisciplinary team meetings (also called tumor boards) at the University Cancer Center Hamburg-Eppendorf, Germany. Two researchers recorded structured field notes from a total of N = 15 multidisciplinary team meetings. Data were analyzed using content analysis and descriptive statistics. RESULTS: Physicians mainly exchanged medical information and based their decision-making on this information. Individual patient characteristics or their treatment preferences were rarely considered or discussed. In the few cases where patient preferences were raised as a topic, this information did not seem to be taken into account in decision-making processes about treatment recommendations. CONCLUSION: The processes in multidisciplinary team meetings we observed did not exhibit shared decision-making. Patient perspectives were absent. If multidisciplinary team meetings wish to become more patient-centred they will have to modify their processes and find a way to include patient preferences into the decision-making process.

Functional Characterization of the Mannitol Promoter of Pseudomonas fluorescens DSM 50106 and Its Application for a Mannitol-Inducible Expression System for Pseudomonas putida KT2440.

A new pBBR1MCS-2-derived vector containing the Pseudomonas fluorescens DSM10506 mannitol promoter PmtlE and mtlR encoding its AraC/XylS type transcriptional activator was constructed and optimized for low basal expression. Mannitol, arabitol, and glucitol-inducible gene expression was demonstrated with Pseudomonas putida and eGFP as reporter gene. The new vector was applied for functional characterization of PmtlE. Identification of the DNA binding site of MtlR was achieved by in vivo eGFP measurement with PmtlE wild type and mutants thereof. Moreover, purified MtlR was applied for detailed in vitro investigations using electrophoretic mobility shift assays and DNaseI footprinting experiments. The obtained data suggest that MtlR binds to PmtlE as a dimer. The proposed DNA binding site of MtlR is AGTGC-N5-AGTAT-N7-AGTGC-N5-AGGAT. The transcription activation mechanism includes two binding sites with different binding affinities, a strong upstream binding site and a weaker downstream binding site. The presence of the weak downstream binding site was shown to be necessary to sustain mannitol-inducibility of PmtlE. Two possible functions of mannitol are discussed; the effector might stabilize binding of the second monomer to the downstream half site or promote transcription activation by inducing a conformational change of the regulator that influences the contact to the RNA polymerase.

Discovery of Recent thecideide brachiopods (Order: Thecideida, Family: Thecideidae) in Sulawesi, Indonesian Archipelago, with implications for reproduction and shell size in the genus Ospreyella.

For the first time thecideide brachiopods have been discovered in the Indonesian Archipelago. All specimens were collected in a water depth of 30 m from an old shipwreck, the "Mutiara", which represents a remarkable habitat for these cryptic brachiopods despite its artificial nature. The thecidellinine species Minutella cf. minuta and the lacazelline species Ospreyella mutiara n. sp. are described and illustrated comprehensively, including their shell ontogeny. The inclusion of the new species O. mutiara in the genus Ospreyella Lüter and Wörheide, 2003 is based on results of an integrated approach combining morphological, ontogenetic and genetic studies. Relevant morphological characters diagnostic for Ospreyella are established. In addition, all Recent lacazelline brachiopod genera are confirmed as valid taxa using molecular methods. The small body size of 0. mutiara and the weakly developed brachidium in comparison to other Ospreyella species as a consequence of heterochrony is discussed in more detail. O. mutiara is the first species of the exclusively gonochoristic genus Ospreyella for which hermaphroditism is now documented.

The BioCASe Monitor Service - A tool for monitoring progress and quality of data provision through distributed data networks.

The BioCASe Monitor Service (BMS) is a web-based tool for coordinators of distributed data networks that provide information to web-portals and data aggregators via the BioCASe Provider Software. Building on common standards and protocols, it has three main purposes: (1) monitoring provider's progress in data provision, (2) facilitating checks of data mappings with a focus on the structure, plausibility and completeness, and (3) verifying compliance of provided data for transformation into other target schemas. Herein two use cases, GBIF-D and OpenUp!, are presented in which the BMS is being applied for monitoring the progress in data provision and performing quality checks on the ABCD (Access to Biological Collection Data) schema mapping. However, the BMS can potentially be used with any conceptual data schema and protocols for querying web services. Through flexible configuration options it is highly adaptable to specific requirements and needs. Thus, the BMS can be easily implemented into coordination workflows and reporting duties within other distributed data network projects.

In vivo and in vitro studies on the carotenoid cleavage oxygenases from Sphingopyxis alaskensis RB2256 and Plesiocystis pacifica SIR-1 revealed their substrate specificities and non-retinal-forming cleavage activities.

Carotenoid cleavage oxygenases are nonheme iron enzymes that specifically cleave carbon-carbon double bonds of carotenoids. Their apocarotenoid cleavage products serve as important signaling molecules that are involved in various biological processes. A database search revealed the presence of putative carotenoid cleavage oxygenase genes in the genomes of Sphingopyxis alaskensis RB2256 and Plesiocystis pacifica SIR-1. The four genes sala_1698, sala_1008, ppsir1_15490 and ppsir1_17230 were cloned and heterologously expressed in carotenoid-producing Escherichia coli JM109 strains. Two of the four encoded proteins exhibited carotenoid cleavage activity. S. alaskensis RB2256 carotenoid cleavage oxygenase (SaCCO), which is encoded by sala_1698, was shown to cleave acyclic and monocyclic substrates. Coexpression of sala_1698 in carotenoid-producing E. coli JM109 strains revealed cleavage activity for lycopene, hydroxylycopene, and dihydroxylycopene. The monocyclic substrate apo-8'-carotenal was cleaved in vitro by purified SaCCO at the 9'/10' and 11'/12' double bonds. The second enzyme, P. pacifica SIR-1 carotenoid cleavage oxygenase (PpCCO), is encoded by ppsir1_15490. PpCCO-mediated carotenoid cleavage requires the presence of either hydroxy or keto groups. PpCCO cleaved zeaxanthin, hydroxylycopene, and dihydroxylycopene, and also the C(50) carotenoids decaprenoxanthin, sarprenoxanthin and sarcinaxanthin, in carotenoid-producing E. coli JM109 strains. Whole cells of E. coli JM109 overexpressing ppsir1_15490mut, a mutant of ppsir1_15490 with enhanced gene expression, were applied for the conversion of carotenoids. Analysis of the carotenoid cleavage products revealed a single cleavage site at the 13'/14' double bond for astaxanthin, and two cleavage sites at the 11'/12' or 13'/14' double bond for zeaxanthin, nostoxanthin, and canthaxanthin.

Immunogenicity of autoantigens.

BACKGROUND: Autoantibodies against self-antigens have been associated not only with autoimmune diseases, but also with cancer and are even found in healthy individuals. The mechanism causing the autoantibody response remains elusive for the majority of the immunogenic antigens. To deepen the understanding of autoantibody responses, we ask whether natural-occurring, autoimmunity-associated and tumor-associated antigens have structural or biological features related to the immune response. To this end, we have carried out the most comprehensive in-silicio study of different groups of autoantigens including large antigen sets identified by our groups combined with publicly available antigen sets. RESULTS: We found evidence for an enrichment of genes with a larger exon length increasing the probability of the occurrence of potential immunogenic features such as mutations, SNPs, immunogenic sequence patterns and structural epitopes, or alternative splicing events. While SNPs seem to play a more central role in autoimmunity, somatic mutations seem to be stronger enriched in tumor-associated antigens. In addition, antigens of autoimmune diseases are different from other antigen sets in that they appear preferentially secreted, have frequently an extracellular location, and they are enriched in pathways associated with the immune system. Furthermore, for autoantibodies in general, we found enrichment of sequence-based properties including coiled-coils motifs, ELR motifs, and Zinc finger DNA-binding motifs. Moreover, we found enrichment of proteins binding to proteins or nucleic acids including RNA and enrichment of proteins that are part of ribosome or spliceosome. Both, homologies to proteins of other species and an enrichment of ancient protein domains indicate that immunogenic proteins are evolutionary conserved and that mimicry might play a central role. CONCLUSIONS: Our results provide evidence that proteins which i) are evolutionary conserved, ii) show specific sequence motifs, and iii) are part of cellular structures show an increased likelihood to become autoimmunogenic.

Biosynthesis of zeaxanthin in recombinant Pseudomonas putida.

Pseudomonas putida KT2440 strain was investigated for biosynthesis of the valuable xanthophyll zeaxanthin. A new plasmid was constructed harboring five carotenogenic genes from Pantoea ananatis and three genes from Escherichia coli under control of an L: -rhamnose-inducible promoter. Pseudomonas putida KT2440 wild type hardly tolerated the plasmids for carotenoid production. Mating experiments with E. coli S17-1 strains revealed that the carotenoid products are toxic to the Pseudomonas putida cells. Several carotenoid-tolerant transposon mutants could be isolated, and different gene targets for relief of carotenoid toxicity were identified. After optimization of cultivation conditions and product processing, 51 mg/l zeaxanthin could be produced, corresponding to a product yield of 7 mg zeaxanthin per gram cell dry weight. The effect of various additives on production of hydrophobic zeaxanthin was investigated as well. Particularly, the addition of lecithin during cell cultivation increased volumetric productivity of Pseudomonas putida by a factor of 4.7 (51 mg/l vs. 239 mg/l).

ABL single nucleotide polymorphisms may masquerade as BCR-ABL mutations associated with resistance to tyrosine kinase inhibitors in patients with chronic myeloid leukemia.

The BCR-ABL K247R change is based on a rare single nucleotide polymorphism occurring likewise in healthy controls and non-hematologic cell types. Despite its juxtaposition to the P-loop, functional analysis showed no alteration compared to non-mutated BCR-ABL. We sought to investigate if other changes in the BCR-ABL kinase domain should be considered as single nucleotide polymorphisms rather than acquired mutations. A total of 911 chronic myeloid leukemia patients after failure or suboptimal response to imatinib were screened for BCR-ABL kinase domain mutations. Single nucleotide polymorphism analysis was based on the search for nucleotide changes in corresponding normal, non-translocated ABL alleles by ABL allele-specific PCR following mutation analysis. In addition to the K247R polymorphism we uncovered five new single nucleotide polymorphisms within the BCR-ABL kinase domain; two of them led to amino acid changes. Single nucleotide polymorphisms could theoretically contribute to primary but not to secondary resistance to tyrosine kinase inhibitors and must therefore be distinguished from acquired mutations. Novel point mutations should be confirmed by analyzing the normal ABL alleles to exclude polymorphisms.

Suitability of the PAXgene system to stabilize bone marrow RNA in imatinib-resistant patients with chronic myeloid leukemia.

BACKGROUND: Optimum sample quality is a crucial requirement for molecular monitoring of patients with chronic myeloid leukemia (CML) on therapy. Bedside RNA stabilization systems (e.g., PAXgene) have been developed to inhibit RNA degradation during shipment of samples from the clinical site to the specialized laboratory. In CML, blood but not bone marrow samples have been examined using RNA stabilization in previous studies. Therefore, we sought to investigate the applicability of the PAXgene system for bone marrow samples in CML. METHODS: Simultaneously stabilized blood and bone marrow samples were obtained from 55 imatinib-resistant CML patients to compare RNA yield and purity, expression of two housekeeping genes (total ABL and beta-glucuronidase; GUS) by quantitative reverse-transcriptase polymerase chain reaction, BCR-ABL expression (ratios BCR-ABL/ABL and BCR-ABL/GUS), and BCR-ABL kinase domain mutations analyzed by denaturing high-performance liquid chromatography and direct sequencing. RESULTS: RNA extraction revealed high-quality RNA derived from both stabilized blood and bone marrow samples. RNA yield was significantly higher in bone marrow (median 9.9 microg RNA/mL bone marrow) than in blood (median 4.3 microg RNA/mL blood) (p=0.0005). The number of housekeeping gene transcripts was comparable in blood and bone marrow (median ABL copies/2 microL cDNA 13,260 vs. 25,590; median GUS copies/2 microL cDNA 35,490 vs. 60,200; n.s.). Further, ratios BCR-ABL/ABL (blood vs. bone marrow, median 47% vs. 57%) and ratios BCR-ABL/GUS (blood vs. bone marrow, median 26% vs. 21%) were not significantly different. Results of mutation analysis corresponded in 51 out of 55 patients (93%), whereas moderate differences were observed in four patients. CONCLUSIONS: We conclude that bone marrow can be effectively stabilized using the PAXgene system and shows concordance with blood in terms of BCR-ABL mRNA quantification and mutation analysis in imatinib-resistant CML patients.

Dynamics of BCR-ABL mutated clones prior to hematologic or cytogenetic resistance to imatinib.

UNLABELLED: background: Mutations of the BCR-ABL tyrosine kinase domain constitute a major cause of resistance to tyrosine kinase inhibitors in patients with chronic myeloid leukemia. We sought to improve the diagnostic armamentarium by screening and to analyze the dynamics of mutated clones in chronic myeloid leukemia patients who experienced hematologic or cytogenetic relapse. DESIGN AND METHODS: Ninety-five patients who relapsed during imatinib therapy were screened for BCR-ABL kinase domain mutations using sensitive denaturing high-performance liquid chromatography (D-HPLC) and direct sequencing. To investigate the dynamics of mutated clones D-HPLC was applied to 453 cDNA samples tracking back from relapse towards the start of imatinib therapy. RESULTS: Twenty-two different point mutations affecting 18 amino acids were detectable in 46/79 (58%) and in 7/16 patients (44%) with hematologic or cytogenetic relapse, respectively. A deletion of 81 nucleotides (del248-274) of ABL exon 4 was observed in two patients. Three patients had exclusively single nucleotide polymorphisms (K247R, T315T, E499E, n=1 each) within the BCR-ABL kinase domain. In patients harboring mutations, hematologic relapse occurred after a median of 12.9 months (range, 0.9-44.2), and BCR-ABL mutations first became detectable at a median of 5.8 months (range, 0-30.5) after starting imatinib therapy (p<0.0001). Nine patients showed evidence of BCR-ABL mutations prior to imatinib therapy (T315I, n=4; M351T, n=3; M244V and Y253H, n=1 each). CONCLUSIONS: We conclude that: (i) D-HPLC is a sensitive method for screening for BCR-ABL mutations before and during therapy with tyrosine kinase inhibitors; (ii) the occurrence of BCR-ABL mutations during imatinib therapy is predictive of relapse; (iii) mutations may be detectable several months before relapse, and (iv) the sensitive detection of small numbers of mutated clones could provide clinical benefit by triggering early therapeutic interventions.