Search

Hyperactivation of the Hedgehog (Hh) pathway, which controls refueling of multiple myeloma (MM) clones, might be critical to disease recurrence. Although several studies suggest the Hh pathway is activated in CD138- immature cells, differentiated CD138+ plasma cells might also be able to self-renew by producing themselves the Hh ligands. We studied the gene expression profiles of 126 newly diagnosed MM patients analyzed in both the CD138+ plasma cell fraction and CD138-CD19+ B-cell compartment. Results demonstrated that an Hh-gene signaturewas able to cluster patients in two subgroups characterized by the opposite Hh pathway expression in mature plasma cells and their precursors. Strikingly, patients characterized by Hh hyperactivation in plasma cells, but not in their B cells, displayed high genomic instability and an unfavorable outcome in terms of shorter progression-free survival (hazard ratio: 1.92; 95% confidence interval: 1.19–3.07) and overall survival (hazard ratio: 2.61; 95% confidence interval: 1.26–5.38). These results suggest that the mechanisms triggered by the Hh pathway ultimately led to identify a more indolent vs a more aggressive biological and clinical subtype of MM. Therefore, patient stratification according to their molecular background might help the fine-tuning of future clinical and therapeutic studies.

Identification of patient sub-groups with smoldering multiple myeloma (SMM) at high risk of progression to active disease (MM) is an important goal. 18F-FDG PET/CT (positron emission tomography (PET) integrated with computed tomography (PET/CT) using glucose labelled with the positron-emitting radionuclide 18F) allows for assessing early skeletal involvement. Identification of osteolytic lesions by this technique has recently been incorporated into the updated International Myeloma Working Group criteria for MM diagnosis. However, no data are available regarding the impact of focal lesions (FLs) without underlying osteolysis on time to progression (TTP) to MM. We hence prospectively studied a cohort of 120 SMM patients with PET/CT. PET/CT was positive in 16% of patients (1 FL: 8, 2 FLs: 3, >3 FLs: 6, diffuse bone marrow involvement: 2). With a median follow-up of 2.2 years, 38% of patients progressed to MM, in a median time of 4 years, including 21% with skeletal involvement. The risk of progression of those with positive PET/CT was 3.00 (95% confidence interval 1.58–5.69, P=0.001), with a median TTP of 1.1 versus 4.5 years for PET/CT-negative patients. The probability of progression within 2 years was 58% for positive versus 33% for negative patients. In conclusion, PET/CT positivity significantly increased the risk of progression of SMM to MM. PET/CT could become a new tool to define high-risk SMM.

After a general introduction the relations between photosynthesis and chlorophyll fluorescence are explained. Subsequently a brief review is presented of earlier work in the field of remote sensing of chlorophyll fluorescence. The objective of the LIFT project is to investigate the possible use of laser induced fluorescence (LIF) for observing and monitoring vegetation stress due to air pollution. The instrumentation and set-up is briefly described and measuring results are presented. Changes in LIF and air pollution are found to be strongly related. The results can be explained in terms of ozone stress, possibly enhanced by SO⊂2⊂. These effects appear at low concentrations of ozone, i.e., below the concentration limit of 30 ppb, recommended in the Netherlands. It is concluded that this new remote sensing technique has a strong potential in the field of environmental mapping and monitoring.

Lidar signatures from fogs can be affected by a substantial contribution from multiple scattering. This latter is strongly dependent on the aperture a of the receiver's field of view. Since lidar IROE IV allows the use of different values of α, an analysis is made of an approximate procedure to process the data in order to extract the single scattering contribution to the received power. Some experimental results are presented.

This paper describes the activity of the IROE Lidar Group in the field of visibility measurements. Lidar visibility measurements were started as early as 1973 in collaboration with the DFVLR of Oberpfaffenhofen (F.R. Germany) and are still progressing as a part of the Air Traffic Control Programme of the CNR. Lidar signatures were obtained in field experiments carried out in 1974, 1976 and 1978 and different processing methods were employed in order to test their reliability. The results of such measurements are discussed in this paper.

The ability of a two-wavelength lidar in the identification of natural and artificial targets is discussed. The analysis is carried out on the basis of target spectral reflectance and taking into account the atmospheric extinction at the two laser wavelengths. Preliminary results performed with a two-wavelength (0·532 and 1·064 μm) Nd-YAG lidar are reported.

Measurements of spectral reflectance of terrestrial surface materials at CO_2 laser wavelengths are reported. Implications on measurement accuracy of long-path airborne differential absorption lidar for atmospheric gas concentration monitoring are discussed. It is also shown that reflectance spectra of most of the terrestrial surface materials are distinguishable enough to enable material identification by remote reflectance measurements at several selected laser wavelengths. This possibility introduces new prospects for active geological (and possibly agricultural) remote sensing.