C1orf194 deficiency leads to incomplete early embryonic lethality and dominant intermediate Charcot-Marie-Tooth disease in a knockout mouse model.

Charcot-Marie-Tooth (CMT) disease is the most common inherited peripheral neuropathy and shows clinical and genetic heterogeneity. Mutations in C1orf194 encoding a Ca2+ regulator in neurons and Schwann cells have been reported previously by us to cause CMT disease. In here, we further investigated the function and pathogenic mechanism of C1or194 by generating C1orf194 knockout (KO) mice. Homozygous mutants of C1orf194 mice exhibited incomplete embryonic lethality, characterized by differentiation abnormalities and stillbirth on embryonic days 7.5-15.5. Heterozygous and surviving homozygous C1orf194 KO mice developed motor and sensory defects at the age of 4 months. Electrophysiologic recordings showed decreased compound muscle action potential and motor nerve conduction velocity in the sciatic nerve of C1orf194-deficient mice as a pathologic feature of dominant intermediate-type CMT. Transmission electron microscopy analysis revealed demyelination and axonal atrophy in the sciatic nerve as well as swelling and loss of mitochondrial matrix and other abnormalities in axons and Schwann cells. A histopathologic examination showed a loss of motor neurons in the anterior horn of the spinal cord and muscle atrophy. Shorter internodal length between nodes of Ranvier and Schmidt-Lanterman incisures was detected in the sciatic nerve of affected animals. These results indicate that C1orf194 KO mice can serve as an animal model of CMT with a severe dominant intermediate CMT phenotype that can be used to investigate the molecular mechanisms of the disease and evaluate the efficacy of therapeutic strategies.

[Drug resistance of extended-spectrum-ß-lactamases-producing bacteria in children with hematological malignancy after chemotherapy].

OBJECTIVE: To study the prevalence and drug resistance of extended-spectrum-ß-lactamases (ESBLs)-producing bacteria in blood culture isolated from children with hematological malignancy after chemotherapy. METHODS: Blood samples taken from 3264 children with hematological malignancy and severe infection following chemotherapy between 2002 and 2008 were cultured using the Bact/ALTER 3D blood culture system. VITEK 60 automicroscan was used to identify viral species and to conduct drug resistance tests. The results were indentified according to National Committee for Clinical Laboratory Standard guidelines. RESULTS: Fifty-eight strains of Escherichia coli and fifty-one strains of Klebsiella pneumoniae were isolated. Thirty-eight strains of Escherichia coli and nineteen strains of Klebsiella pneumoniae were ESBLs-producing and these ESBLs-producing strains were less susceptible than those that were non-ESBLs-producing to most antibiotics. Both ESBL- and non-ESBL-producing strains were susceptible to imipenem, piperacillin/tazobactam and amikacin. CONCLUSIONS: The prevalence of ESBLs-producing bacteria is high in childrn with hematological malignancy and infection following chemotherapy. ESBLs-producing bacteria are resistant to common antibiotics, suggesting that antibiotic treatment based on the result of antimicrobial susceptibility test is necessary in these children.

[Autologous Peripheral Blood Hematopoietic Stem Cell Transplantation with IBu Precondition Regimen in Treatment for 11 Patients with Low to Intermediate Risk Acute Myeloid Leukemia].

OBJECTIVE: To evaluate safety and efficacy of autologous peripheral blood hematopoietic stem cell transplantation (auto-PBHSCT) with IBu precondition regimen consisting of high-dose idarubicin (IDA) and busulphan (Bu) for treatment of patients with low and intermediate risk acute myeloid leuekmia (AML). METHODS: A total of 11 patients with AML (5 low and 6 intermediate risk patients) treated with auto-PBHSCT with IBu precondition regimen (IDA 20 mg/m2, continuous i.v. from d-13 to d-11, Bu 0.8 mg/kg/q6h i.v. for 2h, from d-5 to d-2) from March 2011 to July 2014 were analyzed retrospectively. Adverse effects and transplantation-related mortality (TRM) were evaluated. Kaplan-Meier analysis was performed to calculate the overall survival (OS), disease-free survival (DFS) and cumulative relapse rate (RR). Cox regression was performed for univariate analysis for DFS. RESULTS: Among the 11 patients, 10 patients obtained hematopoietic reconstitution, 1 patient died during transplantation, thus the TRM was 9.1%. The adverse effects were well tolerated. With median follow-up of 31.6 (8.7-52.5) months, 7 patients (63.3%) were alive, including 6 patients (54.5%) in continuous complete remission (CR). Median OS and DFS were not reached. The 3-year OS, DFS and RR were (57.7±16.3)%, (52.5±17.6)% and 47.5%, respectively. Univartiate analysis indicated that the age, sex, interval between diagnosis and transplantation, white blood cell count at diagnosis, risk-grouping (low or intermediate risk), disease status before transplantation (CR1 or CR2), and count of mononuclear cells for infusion all can not influence DFS(P>0.05, respectively). CONCLUSION: The treatment of auto-PBHSCT with IBu precondition regimen for low to intermediate risk AML patients is safe and effective.