Given an abstract, generate a keyword (a noun phrase) that best describes the focus or contribution of the paper. Such keywords can be directly from the given abstract or outside it.

Abstract: The prognostic value of marrow chromosome findings was examined in 242 patients with preleukemic myelodysplastic syndromes (MDS) or myeloproliferative disorders (MPD), with emphasis on the significance of single versus multiple karyotypic changes. In both groups, the results showed that patients with multiple chromosome abnormalities in a marrow clone had a very high probability of early death, from progression to leukemia or from other complications of hematopoietic dysfunction. Conversely, in patients with a hemic clone having only one karyotypic alteration (involving a single chromosome or single translocation), survival over 2 years was only slightly reduced as compared to those without chromosome abnormality. The only single karyotypic alteration perhaps associated with a markedly shortened survival was monosomy 7. These findings suggest that the conclusions of previous studies concerning the grave consequences of chromosome alterations in preleukemia largely reflect the clinical significance of clones with multiple cytogenetic changes. Prior knowledge of the karyotypic status of preleukemic patients should be helpful in evaluating current attempts to find effective treatment for these difficult disorders.
Aged

Abstract: Four patients with recurrent severe angina and evidence of myocardial ischemia two to six months after surgical coronary revascularization have been submitted to percutaneous transluminal angioplasty of the distal insertion of internal mammary artery grafts or of the recipient vessel distal to it. These cases illustrate the feasibility and safety of transluminal angioplasty of right and left internal mammary artery grafts, using the mammary artery as a way of access.
Adult

Abstract: The authors have investigated the application of mode-locked and Q-switched Neodymium:YAG (Nd:YAG) lasers in ocular surgery by means of high-speed photography and hydrophone measurements. The incisive effect relies on the optical breakdown at the laser focus. Cavitation bubbles and acoustic transients are thereby generated. Their size and pressure amplitude have been measured at various laser-pulse energies. With a pulse energy of 5 mJ, the bubble is 1.5 to 2.3 mm in diameter and the pressure of the acoustic transient is 9 to 16 bar (130 to 230 psi) at a distance of 18 mm from the focal point. Bubble size and amplitude of the pressure pulse are always approximately 50% higher with a Q-switched laser than with a mode-locked laser. However, the size of the ruptures produced in a polyethylene membrane by the laser pulses is the same for both modes of operation. The energy balance shows that not only mechanical effects, but also thermal mechanisms are responsible for photodisruption.
Acoustics