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Publications and source records attributed to S Ahn.
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Left ventricular function and neurohormonal status in patients with heart failure remaining symptomatic during therapy with angiotensin-converting enzyme inhibitors were assessed, and the effects of dopaminergic receptor stimulation in this setting were determined. Neurohormonal and left ventricular function (radionuclide angiography) data were obtained in 19 patients with symptomatic ischemic heart failure. Measurements were repeated after 4 to 6 weeks of therapy with the dopamine agonist ibopamine (100 mg, 3 times/day) or placebo administered in a double-blind, randomized, parallel group design. At baseline, despite therapy with enalapril, the angiotensin II levels (mean 39.4 pg/ml; p < 0.01 vs controls) were significantly increased, as were plasma norepinephrine (497 +/- 240 pg/ml; p < 0.01 vs controls), endothelin-1, atrial natriuretic peptide and arginine vasopressin. Moreover, in comparison with pretreatment values, left ventricular ejection fraction had decreased substantially (-9.1%) in patients with plasma norepinephrine > or = 600 pg/ml, but not in those with lower values of norepinephrine. With ibopamine, plasma norepinephrine decreased from 516 +/- 241 to 391 +/- 208 pg/ml (n = 8; p < 0.025 vs placebo), whereas it increased with placebo. In conclusion, the neurohormonal control provided by an angiotensin-converting enzyme inhibitor is reduced in a large subset of patients during prolonged therapy; ibopamine appears to be a potentially useful drug to improve neurohormonal control in this setting.
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OBJECTIVES: This study was performed to assess the quality of life of patients with left ventricular dysfunction for up to 2 years after randomization to enalapril or placebo. BACKGROUND: Previous reports have documented that survival of patients with congestive heart failure can be extended by the angiotensin-converting enzyme inhibitor enalapril. However, it is unknown whether enalapril has a long-term favorable impact on the quality of life in patients with heart failure. METHODS: A brief quality of life questionnaire assessing the quality of life was administered at baseline and at 6 weeks, 1 year and 2 years of follow-up to patients randomized to placebo or enalapril in the Studies of Left Ventricular Dysfunction (SOLVD). Participants had an ejection fraction < or = 0.35, no other serious illnesses and either symptomatic heart failure (treatment trial, n = 2,465) or asymptomatic left ventricular dysfunction (prevention trial, n = 2,560). RESULTS: Among the 14 scales of quality of life, better scores at one or more follow-up intervals were noted in 6 scales in the treatment trial and in 1 scale in the prevention trial among patients assigned to enalapril. Consistent superiority with enalapril at two consecutive follow-up intervals was noted in the treatment trial for social functioning and dyspnea but for no scale in the prevention trial. However, an average of 40% of quality of life responses were missing at 2 years of follow-up because of death or failure to complete the questionnaire. In the treatment trial, survivors with more severe heart failure were less likely to complete the questionnaire. CONCLUSIONS: Modest benefits in quality of life for > or = 1 year occurred when patients with left ventricular dysfunction and symptomatic heart failure were treated with enalapril. No apparent beneficial or adverse effect on quality of life was observed with enalapril in asymptomatic patients with left ventricular dysfunction.
The effects of nisoldipine on regional myocardial perfusion and neuro-hormonal status were assessed in a double-blind, placebo-controlled study of 32 patients. All patients had ischaemic left ventricular dysfunction, with a left ventricular ejection fraction between 25% and 35%; per protocol, they were stratified according to concomitant use of ACE inhibitors. After baseline measurements at rest, including single photon emission computed tomography (SPECT) with Tc-MIBI, plasma neuro-hormones (norepinephrine, renin, arginine vasopressin, atrial natriuretic peptide) and echocardiography, the patients were randomized to nisoldipine (core coat tablet, 20 mg once daily; n = 16) or placebo (n = 16). Measurements were repeated after 8 weeks. SPECT data were analysed qualitatively (visual comparison by blinded observer) and quantitatively to derive an index of hypoperfusion representing the percentage of the left ventricular mass with Tc-MIBI activity below normal. At baseline, all patients had left ventricular areas with reduced Tc-MIBI uptake and 29 patients also had increases in plasma neuro-hormones. With nisoldipine, the extent of hypoperfusion (quantitative analysis) was reduced in 8/14 patients vs only 2/14 patients with placebo (P = 0.046, 2-tailed test). The benefit of nisoldipine was similar in patients with or without ACE inhibitor therapy and was also confirmed by the visual analysis of the data. Further, none of the neuro-hormones examined was significantly modified by nisoldipine. Thus, chronically underperfused areas are present at rest in patients with ischaemic left ventricular dysfunction, and nisoldipine significantly improved Tc-MIBI uptake in these areas without evidence of detrimental changes in plasma neuro-hormones.(ABSTRACT TRUNCATED AT 250 WORDS)
Genetic linkage maps have been constructed for the rice and maize genomes on the basis of orthologous loci detected with a common set of cDNA clones. Conserved linkage groups could be identified, which together account for more than two-thirds of both genomes. In some instances, entire chromosomes or chromosome arms are nearly identical with respect to gene order and gene content. The results also reveal that most of the genes (> 72%) duplicated during ancient polyploidization are still present in the maize genome in duplicate copy. The comparative maps of rice and maize provide a basis for interpreting molecular, genetic, and breeding information between these two important species and establish a framework for ultimately connecting the genetics of all grass species.