Predictors of survival in patients with systemic light-chain amyloidosis and cardiac involvement initially ineligible for stem cell transplantation and treated with oral melphalan and dexamethasone.

The treatment of systemic light-chain (AL) amyloidosis with symptomatic cardiac involvement at diagnosis remains a challenge. We report the results of 40 consecutive newly diagnosed AL cardiac patients who were not candidates for stem cell transplant and therefore received monthly oral melphalan and dexamethasone. Median survival was 10.5 months and baseline predictors of survival included gender, troponin I and interventricular septal thickness. The most significant predictor of survival was response to therapy. The haematological response rate was 58% (23/40) with 13% (5/40) complete responses; most responses were noted in <3 cycles. Achievement of a rapid response to therapy extends survival.

Horizontal Line-of-Sight Turbulence Over Near-Ground Paths and Implications for Adaptive Optics Corrections in Laser Communications.

Atmospheric turbulence over long horizontal paths perturbs phase and can also cause severe intensity scintillation in the pupil of an optical communications receiver, which limits the data rate over which intensity-based modulation schemes can operate. The feasibility of using low-order adaptive optics by applying phase-only corrections over horizontal propagation paths is investigated. A Shack-Hartmann wave-front sensor was built and data were gathered on paths 1 m above ground and between a 1- and 2.5-km range. Both intensity fluctuations and optical path fluctuation statistics were gathered within a single frame, and the wave-front reconstructor was modified to allow for scintillated data. The temporal power spectral density for various Zernike polynomial modes was used to determine the effects of the expected corrections by adaptive optics. The slopes of the inertial subrange of turbulence were found to be less than predicted by Kolmogorov theory with an infinite outer scale, and the distribution of variance explained by increasing order was also found to be different. Statistical analysis of these data in the 1-km range indicates that at communications wavelengths of 1.3 mum, a significant improvement in transmitted beam quality could be expected most of the time, to a performance of 10% Strehl ratio or better.

Measurements of the wavelength dependence and other properties of stellar scintillation at Mauna Kea, Hawaii.

The variance of intensity of stellar scintillation has been measured as a function of wavelength using photon counting and on-line digital analysis techniques. The experimental data are consistent with that predicted by the theory of Tatarski. Measurements of the temporal correlation function of intensity and the higher moments of the probability density function of scintillation are also described. Time scales in the 1.7-10-msec range were observed, and the observed higher moments were consistently lower than those predicted by a log normal distribution. All the measurements were made at Mauna Kea Observatory, Hawaii.