Polyvinyl Chloride Modified Carbon Paste Electrodes for Sensitive Determination of Levofloxacin Drug in Serum, Urine, and Pharmaceutical Formulations.

Levofloxacin (LF) is a medically important antibiotic drug that is used to treat a variety of bacterial infections. In this study, three highly sensitive and selective carbon paste electrodes (CPEs) were fabricated for potentiometric determination of the LF drug: (i) CPEs filled with carbon paste (referred to as CPE); (ii) CPE coated (drop-casted) with ion-selective PVC membrane (referred to as C-CPE); (iii) CPE filled with carbon paste modified with a plasticizer (PVC/cyclohexanone) (referenced as P-CPE). The CPE was formulated from graphite (Gr, 44.0%) and reduced graphene oxide (rGO, 3.0%) as the carbon source, tricresyl phosphate (TCP, 47.0%) as the plasticizer; sodium tetrakis[3,5-bis(trifluoromethyl)phenyl] borate (St-TFPMB, 1.0%) as the ion exchanger; and levofloxacinium-tetraphenylborate (LF-TPB, 5.0%) as the lipophilic ion pair. It showed a sub-Nernstian slope of 49.3 mV decade-1 within the LF concentration range 1.0 × 10-2 M to 1.0 × 10-5 M, with a detection limit of 1.0 × 10-5 M. The PVC coated electrode (C-CPE) showed improved sensitivity (in terms of slope, equal to 50.2 mV decade-1) compared to CPEs. After the incorporation of PVC paste on the modified CPE (P-CPE), the sensitivity increased at 53.5 mV decade-1, indicating such improvement. The selectivity coefficient (log KLF2+,Fe+3pot.) against different interfering species (Na+, K+, NH4+, Ca2+, Al3+, Fe3+, Glycine, Glucose, Maltose, Lactose) were significantly improved by one to three orders of magnitudes in the case of C-CPE and P-CPE, compared to CPEs. The modification with the PVC membrane coating significantly improved the response time and solubility of the LF-TPB within the electrode matrix and increased the lifetime. The constructed sensors were successfully applied for LF determination in pharmaceutical preparation (Levoxin® 500 mg), spiked urine, and serum samples with high accuracy and precision.

Outcome of Childhood Acute Myeloid Leukemia With FLT3-ITD Mutation: The Experience of Children's Cancer Hospital Egypt, 2007-17.

INTRODUCTION: The presence of FMS-like tyrosine kinase 3 (FLT3) internal tandem duplication (ITD) mutation in pediatric acute myeloid leukemia (AML) is associated with high rates of induction failure and worse survival. Its presence places the patient into a high-risk group. We aimed to describe the outcome of pediatric AML with FLT3-ITD mutation. PATIENTS AND METHODS: We performed a retrospective analysis of cases of AML from July 2007 till July 2017 at Children's Cancer Hospital Egypt. RESULTS: Seventy-one patients had FLT3 gene mutation out of 687 patients with AML. Sixty-five patients had FLT3 gene mutation with allelic ratio > 0.4; 43 (66.1%) of 65 patients experienced complete remission (CR). Of the 43 patients, 16 patients maintained CR, 18 patients relapsed after first CR, 8 patients died, and 1 patient was lost to follow-up. Patients with relapsing disease died after salvage chemotherapy, except for one patient, who was alive after second CR. Allogeneic bone marrow transplantation (allo-BMT) was performed for 9 (13.8%) of 65 patients in first CR, of whom 8 were alive and in CR, and 1 patient experienced disease relapse and died. Seven patients (10.7%) were alive without allo-BMT. Three years' overall and event-free survival for patients with FLT3-ITD mutation with high allelic ratio was 26.9% and 22.8%, respectively. Three years' overall and event-free survival for patients treated with allo-BMT was 77.8% and 78.8%, respectively, versus patients treated without allo-BMT, 16.3% and 12.8%, respectively. CONCLUSION: FLT3-ITD mutation in pediatric AML was associated with poor treatment outcomes, and the survival of relapsing patients was extremely poor. Allo-BMT in first remission was the best treatment option. Alternative donor transplants and FLT3 inhibitors are needed to improve outcome in developing countries.

Outcome of Childhood Acute Megakaryoblastic Leukemia: Children's Cancer Hospital Egypt 57357 Experience.

INTRODUCTION: Acute megakaryoblastic leukemia is a rare subtype of pediatric acute myeloid leukemia (AML) with poor outcomes in patients with non-Down syndrome. The reported outcomes have been poor, and the prognostic factors have not been clearly determined. PATIENTS AND METHODS: To evaluate the prognostic significance of various cytogenetic abnormalities and minimal residual disease status determined by flow cytometry after induction I, we retrospectively analyzed the data of 80 patients with non-Down syndrome with a diagnosis of M7 AML treated at Children's Cancer Hospital Egypt (CCHE-57357) from July 2007 through December 2016. RESULTS: Of the 80 patients, 15 died during induction I and were excluded from the survival analysis. The overall survival, event-free survival, and cumulative incidence of relapse at 2 years was 52.6% ± 12.7%, 45.2% ± 12.3%, and 31.8% ± 11.5% respectively. Of the 90 patients, 61 had cytogenetic abnormalities, including trisomy 19,13q, trisomy 8, complex karyotype, t(1;22), KMT2A rearrangements, and trisomy 21. None of these had an effect on the outcomes. In addition, 34 patients had minimal residual disease < 0.1% after induction I, but the difference did not reach statistical significance. Patients with a delayed time to recovery (possibly due to myelofibrosis) had worse outcomes compared with those with early recovery (47% ± 19.2% vs. 63.2% ± 21.9%, respectively). CONCLUSION: Acute megakaryoblastic leukemia in patients with non-Down syndrome has a poor outcome with no clearly defined prognostic factors. However, future directions to risk stratify and tailor therapy should include assessment of the tumor biology according to the molecular pathways and study of the pathogenesis of myelofibrosis in this disease, which could affect the prognosis.