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The incidence of acute myeloid leukemia (AML) increases with age. Elderly patients with AML are less tolerant to high-intensity consolidation therapy than younger patients, with significantly worse prognoses. Induction and consolidation therapy combined with allogeneic hematopoietic stem cell microtransplantation may improve the prognosis of elderly patients with AML. The present study reports the effect of maintenance therapy with low-dose chemotherapy treatment combined with microtransplantation in elderly patients with AML following consolidation. Between January 2011 and April 2014, three elderly patients (>55 years old), including one 58-year-old patient with acute mixed lineage leukemia (AMLL) and two patients with AML aged 59 years and 62 years, underwent microtransplantation maintenance therapy. Following a complete response to induction chemotherapy and consolidation chemotherapy with two to four cycles of medium dose Ara-c (auto transplantation was performed in the patient with AMLL), maintenance therapy was performed using low-dose Ara-c combined with human leukocyte antigen haploidentical allogeneic hematopoietic stem cell microtransplantation, which was repeated every 3 to 6 months. The patients were followed up for 27, 20 and 16 months, respectively, and all three patients achieved disease-free survival. The bone marrow Wilms' tumor suppression gene (WT1) level of the case with AMLL was dynamically monitored. The results showed that the WT1 level was abnormally high prior to microtransplantation and gradually declined to normal levels subsequent to the process. None of the patients suffered from graft versus host disease during the microtransplantation process. In conclusion, microtransplantation maintenance therapy following consolidation therapy is feasible in elderly patients with AML, and is expected to be able to further remove residual lesions and improve treatment efficacy. A large-scale clinical trial is required to confirm the effect of maintenance therapy in elderly patients with AML. [ABSTRACT FROM AUTHOR]

Background: Assessing the non-random associations of alleles at different loci, or gametic disequilibrium, can provide clues about aspects of population histories and mating behavior and can be useful in locating disease genes. For gametic data which are available from several strata with different allele probabilities, it is necessary to verify that the strata are homogeneous in terms of gametic disequilibrium. Results: Using the likelihood score theory generalized to nuisance parameters we derive a score test for homogeneity of gametic disequilibrium across several independent populations. Simulation results demonstrate that the empirical type I error rates of our score homogeneity test perform satisfactorily in the sense that they are close to the pre-chosen 0.05 nominal level. The associated power and sample size formulae are derived. We illustrate our test with a data set from a study of the cystic fibrosis transmembrane conductance regulator gene. Conclusion: We propose a large-sample homogeneity test on gametic disequilibrium across several independent populations based on the likelihood score theory generalized to nuisance parameters. Our simulation results show that our test is more reliable than the traditional test based on the Fisher's test of homogeneity among correlation coefficients. [ABSTRACT FROM AUTHOR]

Motivation: Inference of identical-by-descent (IBD) probabilities is the key in family-based linkage analysis. Using high-density single nucleotide polymorphism (SNP) markers, one can almost always infer haplotype configurations of each member in a family given all individuals being typed. Consequently, the IBD status can be obtained directly from haplotype configurations. However, in reality, many family members are not typed due to practical reasons. The problem of IBD/haplotype inference is much harder when treating untyped individuals as missing. [ABSTRACT FROM PUBLISHER]