Citations

Abstract Pomalidomide at doses of 2 or 4 mg/d has demonstrated excellent activity in patients with multiple myeloma (MM). We opened 2 sequential phase 2 trials using the pomalidomide with weekly dexamethasone (Pom/dex) regimen at differing doses to study the efficacy of this regimen in patients who have failed both lenalidomide and bortezomib. Pomalidomide was given orally 2 or 4 mg daily with dexamethasone 40 mg weekly. Thirty-five patients were enrolled in each cohort. Confirmed responses in the 2-mg cohort consisted of very good partial response (VGPR) in 5 (14%), partial response (PR) in 4 (11%), minor response (MR) in 8 (23%) for an overall response rate of 49%. In the 4-mg cohort, confirmed responses consisted of complete response (CR) in 1 (3%), VGPR in 3 (9%), PR in 6 (17%), MR in 5 (14%) for an overall response rate of 43%. Overall survival at 6 months is 78% and 67% in the 2- and 4-mg cohort, respectively. Myelosuppression was the most common toxicity. This nonrandomized data suggests no advantage for 4 mg over the 2 mg daily. Pomalidomide overcomes resistance in myeloma refractory to both lenalidomide and bortezomib. This trial is registered at http://ClinicalTrials.gov, number NCT00558896.

Abstract Mind body therapies appear to reduce morbidity and mortality in patients with cardiovascular diseases, but there is limited understanding of the mechanisms that mediate this effect. Vascular endothelial dysfunction is a central feature of atherogenesis that is adversely impacted by mental stress. We conducted a systematic review and meta-analysis of the effect of mind body therapies on peripheral endothelial function in patients with and without established cardiovascular disease. The search included Medline, Cochrane Library, Scopus and Embase to identify studies up to November 2009. Eligible studies were randomized controlled trials that compared the effects of mind body therapies and placebo on endothelial function. Two reviewers extracted data on study characteristics, methods, and outcomes. Disagreement was resolved by consensus. Three eligible trials enrolled a total of 258 patients. Sixty one (24 percent) were women and 53 percent had established cardiovascular disease. The trials had good methodological quality. Meta-analysis using random-effects model showed a non significant improvement of endothelial function by mind body therapies (standardized mean difference 0.15; 95% CI, -0.36 to 0.67, P=0.56). The analysis was underpowered due to small sample size. Circumstantial evidence indicates that mind body therapies may have a therapeutic benefit on endothelial dysfunction, however, the aggregate data from the three small randomized trials to date do not support this hypothesis. This biologically plausible effect requires additional investigation in adequately powered studies.

Recent studies demonstrate that endothelin, a potent endogenous vasoconstrictor peptide, circulates in plasma of normal animals and humans. However, the role of this peptide in pathophysiological states remains unclear. The present study was designed to test the hypothesis that circulating endothelin concentrations are increased in experimental congestive heart failure (CHF), a pathophysiological state characterized by activation of vasoconstrictor mechanisms. In anesthetized dogs with CHF produced by 8 days of rapid ventricular pacing (n = 28), circulating plasma endothelin was increased compared with values for normal controls (n = 28; 20.4 +/- 1.4 versus 9.7 +/- 0.9 pg/ml, respectively; p less than 0.0001). A plasma endothelin level of more than 14.0 was a sensitive and specific indicator of significant CHF. Moreover, within the group with experimental CHF, right atrial pressure and pulmonary capillary wedge pressure correlated independently with circulating endothelin levels. Based on recent studies demonstrating the physiological actions of twofold increases in circulating endothelin, as observed in the present study, a possible role for endothelin in the pathophysiology of CHF is advanced.

A model of proliferative human restenosis was developed in domestic pigs by using deep injury to the coronary arterial media. Metal wire coils were delivered percutaneously to the coronary arteries of 11 pigs with an oversized, high-pressure (14 atm) balloon and were left in place for times ranging from 28 to 70 days. During placement, the balloon expanded the coils and delivered them securely within the arterial lumen. Light microscopic examination of the vessels confirmed fracture of the internal elastic lamina by the coil. An extensive proliferative response occurred in 10 of the 11 pigs and was associated with a luminal area narrowing of at least 50% in all but one pig. The histopathologic features of the proliferative response were identical to those observed in human cases of restenosis after angioplasty. Immunohistochemical studies confirmed the prominence of smooth muscle cells in the proliferative tissue. A similar response was obtained in two of five porcine coronary arteries in which balloon inflation only was performed, without coil implant. This model is practical and inexpensive and closely mimics the proliferative portion of human restenosis both grossly and microscopically. Thus, it may be useful for understanding human restenosis and for testing therapies aimed at preventing restenosis after balloon angioplasty or other coronary interventional procedures.

Three dosages (0.3, 0.7, and 1.0 mg/kg) of recombinant hirudin, a specific inhibitor of thrombin, were compared with heparin (50 units/kg) and placebo for reducing thrombus formation in the carotid arteries of 50 pigs after deep injury by balloon dilatation. Each drug was administered as a bolus followed immediately by a continuous infusion of the same dose per hour. Major end points were quantitative indium-111-labeled platelet and iodine-125-labeled fibrinogen deposition and the incidence of mural thrombosis. This study showed that heparin, at a dose that prolonged the activated partial thromboplastin time (APTT) to twice the control time, did not prevent mural thrombosis or significantly reduce platelet deposition compared with placebo but did reduce fibrinogen deposition. Recombinant hirudin markedly reduced platelet and fibrinogen deposition in a dose-related manner and totally eliminated mural thrombosis at an APTT of two to three times that of control. Platelet deposition (x 10(6)/cm2, mean +/- SEM) in areas of deep arterial injury for the placebo, heparin, and 0.3, 0.7, and 1.0 mg/kg hirudin groups was 54 +/- 21, 33 +/- 9, 22 +/- 6, 8 +/- 1, and 7 +/- 1, respectively; electron microscopy showed a single layer (or less) of platelets at the two highest hirudin dosages. The incidence of macroscopic mural thrombosis was 76% with placebo, 57% with heparin, 46% with 0.3 mg/kg hirudin; there were no thrombi with 0.7 or 1.0 mg/kg hirudin (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

The present studies were designed to determine the action of neutral endopeptidase inhibition (NEP-I), an inhibitor of the degradation of atrial natriuretic factor (ANF), in congestive heart failure (CHF). Studies were conducted in two groups of anesthetized dogs with CHF induced by 8 days of rapid right ventricular pacing. Group 1 (n = 5) received a specific NEP-I (SQ 28,603) at two doses administered sequentially -30 mg/kg followed by a 60 mg/kg i.v. bolus. Group 2 (n = 5) received intravenous infusion of exogenous ANF (100 ng/kg/min) to achieve increases in plasma ANF concentration as observed in group 1. NEP-I resulted in a diuresis and natriuresis (p less than 0.05) with increases in the fractional excretion of sodium and fractional excretion of lithium, the latter a marker for proximal tubule sodium delivery. Such tubular actions occurred in the absence of increases in glomerular filtration rate or renal blood flow but were associated with significant increases in urinary ANF and urinary cyclic GMP. Plasma ANF increased after the 30 mg/kg NEP-I dose. In contrast, in group 2 with exogenous ANF and despite a marked increase in plasma ANF, no natriuresis was observed. Arterial pressure did not change in either group. These studies demonstrate for the first time in CHF that NEP-I may potentiate the natriuretic action of endogenous ANF by a mechanism that is independent of systemic or renal hemodynamics and does not parallel increases in plasma ANF. These studies support an important therapeutic role for NEP-I in CHF.

Experiments were designed and performed to determine whether endothelial function remained chronically impaired after coronary artery reperfusion. Canine left anterior descending coronary arteries were exposed to ischemia (60 minutes) followed by reperfusion (12 weeks). Rings (3-4 mm wide) of the reperfused artery and of normal left circumflex (control) coronary artery segments were suspended in organ chambers containing physiological saline solution (37 degrees C, gassed with 95% O2-5% CO2) for isometric force measurement. Endothelium-independent contractions to KCl or prostaglandin F2 alpha and endothelium-independent relaxations to nitric oxide or isoproterenol were comparable in control and chronically reperfused arteries. However, chronically reperfused coronary arteries exhibited impaired endothelium-dependent relaxations to aggregating platelets. In addition, the reperfused coronary arteries exhibited impaired endothelium-dependent relaxations to the platelet-derived compounds adenosine diphosphate, serotonin, and thrombin. However, the endothelium-dependent relaxations to acetylcholine were comparable between control and reperfused arteries. Thus, after 12 weeks of reperfusion, previously occluded coronary arteries exhibited a selective impairment of endothelium-dependent relaxation evoked by aggregating platelets. In vivo, this phenomenon could favor platelet adhesion, aggregation, and platelet-induced contraction of coronary smooth muscle and thus facilitate ischemic events such as vasospasm and coronary thrombosis.