Magnetic Resonance Imaging of Bone Marrow and its Results as a Criterion for Administration of Maintenance Therapy After Auto-HSCT in Multiple Myeloma Patients

Aim. To evaluate the efficacy of maintenance therapy in multiple myeloma (MM) patients after autologous hematopoietic stem cell transplantation (auto-HSCT) based on the results of MRI of bone marrow. Materials & Methods. The study included 32 MM patients aged 36 to 66 years (median 57 years) with complete remission after a single auto-HSCT. MRI of spine and pelvic bones was performed to identify the nature of bone marrow lesions and to determine the volume of tumor tissue on the day 100 after auto-HSCT. As maintenance therapy after auto-HSCT 14 patients received daily 15 mg lenalidomide in the period from day 1 to day 21 of the 28-day treatment course within 1 year. Monitoring of 18 patients was conducted without maintenance therapy. Statistical analysis included the assessment of progression-free survival (PFS) and relapse risk relationship to clinical and laboratory parameters. Results. Twenty patients had a positive MRI (tumor volume > 1 cm3). Zero variation of MR signal in bone marrow and detection of a < 1 cm3 tumor were regarded as a negative MRI, which was the case in 12 patients. After reaching the negative MRI the best rates of 2-year PFS were registered: 100 % with maintenance therapy and 84 % without maintenance therapy. In patients with tumor load on MR scans the 2-year PFS significantly (p = 0.03) varied and accounted for 80 % in patients who received maintenance therapy vs. 33 % in patients without maintenance therapy. Administration of maintenance therapy after detecting residual tumor on MR scans on day 100 after auto-HSCT has a positive effect on PFS rates. Multivariate analysis confirmed the residual tumor on MR scans of bone marrow to be the most important parameter PFS depends on. Conclusion. A negative MRI after auto-HSCT is a favourable prognostic factor determining a long-lasting (> 2 years) MM free period, despite the lack of maintenance therapy

Applying physicochemical approaches to control phosphogypsum heavy metal releases in aquatic environment

One of the most important sources of solid waste in the Mediterranean Basin ecosystem originated from the phosphate fertilizer industries, which discharge phosphogypsum (PG) directly into aquatic environments or are stacked on stockpiles. The present study investigates metal release from PG under the influence of variable pH, increasing PG mass content, and complexing organic matter ligands. Major ions from PG leachates, grain size and charge, main functional groups along with metal leachability (Pb, Cd, Cr, Cu, and Zn) were determined using ion chromatography, laser diffraction, zetameter, Fourier transform infrared spectroscopy, and atomic absorption spectroscopy, respectively. The complete dissolution of PG recorded is at 2 g/L. Saturation and supersaturation with respect to PG may occur at concentrations of 3 and 4 g/L, respectively, revealing a clustering phenomenon leading to heavy metal encapsulation within the aggregates. Organic ligands such as citrate may trigger the cationic exchange within the PG suspension leading to ion release. As these factors are considered as specific process involving the release of contaminants from PG during storage under natural conditions, this study could set the foundations for PG remediation in aquatic environment. Organic ligands under controlled pH conditions could be utilized in treating fertilizer industrial wastes by taking into consideration the particularity of the receiving area, thus decreasing metal hazardous impact on natural media. © 2013 Springer-Verlag Berlin Heidelberg.SCOPUS: ar.jSCOPUS: ar.jinfo:eu-repo/semantics/publishe