The upper GI safety and tolerability of oral alendronate at a dose of 70 milligrams once weekly: a placebo-controlled endoscopy study

OBJECTIVE: Alendronate (10 mg daily) has been shown in long term clinical trials to be an effective treatment for postmenopausal osteoporosis. A weekly dosing regimen of alendronate is preferred by both patients and physicians, as it has the potential to provide greater convenience and enhance compliance. In a 1-yr clinical trial, alendronate (70 mg once weekly) was equally efficacious and at least as well tolerated as the 10-mg daily dose in the treatment of postmenopausal osteoporosis, despite the higher unit dosage required. We conducted a randomized, double blind, placebo- and active-controlled endoscopy study to confirm the results of this clinical trial. We hypothesized that mean endoscopic gastric erosion scores would be similar in subjects receiving alendronate (70 mg once weekly) and those receiving a placebo. METHODS: Two hundred seventy-seven subjects (90 men and 187 women) were randomized to one of three treatment groups: 1) alendronate (70 mg once weekly) for 10 wk (N = 126), 2) placebo (once weekly) for 10 wk (N = 126), or 3) placebo (once weekly) for 10 wk followed by aspirin (650 mg q.i.d.) for the last week as the positive control (N = 25). Esophagogastroduodenoscopy was performed 5 to 7 days after the last dose of alendronate or matching placebo. RESULTS: The mean gastric erosion scores (Lanza scale) were similar in subjects given alendronate (70 mg once weekly) and those given a placebo (0.32 vs 0.35, respectively; 95% CI for difference = -0.22-0.16, p = 0.75), whereas scores in both groups were significantly lower than in those given aspirin (3.09; p < 0.001). Endoscopic gastroduodenal ulcers occurred in no alendronate (0%), two placebo (1.7%), and five aspirin (23.8%) subjects. The mean erosion scores in the esophagus and duodenum of alendronate and placebo subjects were also similar. The incidences of upper GI symptoms were similar in the alendronate and placebo subjects and did not suggest a relationship with endoscopic lesions. CONCLUSIONS: Alendronate (70 mg once weekly) was not associated with any increase in endoscopic lesions in the upper GI tract relative to a placebo.     

Expression and functional role of urokinase-type plasminogen activator receptor in normal and acute leukaemic cells

Urokinase-type plasminogen activator receptor (UPA-R-CD87) is a GPI-anchored membrane protein which promotes the generation of plasmin on the surface of many cell types, probably facilitating cellular extravasation and tissue invasion. A flow cytometric quantitative analysis of expression levels for UPA-R was performed on fresh blast cells from patients with acute myeloid leukaemia (AML, n = 74), acute lymphoblastic leukaemia (ALL, n = 24), and biphenotypic leukaemia (BAL, n = 3) using two CD87 monoclonal antibodies (McAbs) (3B10 and VIM5). Peripheral blood and bone marrow (BM) cells from 15 healthy adults served as controls. Using 3B10 McAb, UPA-R was expressed (>99%) by blood monocytes, neutrophils, and BM myelomonocytic precursors in controls, whereas resting T and B lymphocytes, and CD34⁺ cells were UPA-R negative. We also attempted to clarify whether UPA-R has a role in mediating neutrophil functions. Oriented locomotion induced by different chemotaxins and lysozyme release by granules stimulated with fMLP or PMA were significantly decreased when UPA-R was neutralized by CD87 McAb. In contrast, the anti-UPA-R McAb had no effect on superoxide anion generation of normal neutrophils. Blasts from AML showed a heterogenous pattern of expression for the UPA-R McAbs, with reactivity strictly dependent on FAB subtype. The highest UPA-R expression was seen in the M5 group: all patients tested (n = 20) showed strong positivity for the UPA-R McAb whereas only 12% (3/24) of ALL patients were CD87 positive, and 2/3 of BAL patients showed a dim expression for CD87. The number of receptors expressed by blast cells in 6/74 (8.1%) AML patients was higher than those of normal samples; in addition, since co-expression of UPA-R and CD34 was not found in normal haemopoietic cells, it may be postulated that CD87 can be used alone (when overexpressed) or in combination with CD34 for the detection of minimal residual disease. Results also indicated that patients with UPA-receptors >12 × 10³ ABC/cell, irrespective of FAB subtype, had a greater tendency for cutaneous and tissue infiltration and a higher frequency of chromosome abnormalities, thus suggesting the concept that cellular UPA-R content positively correlates with the invasive potential of AML cells. The combination of higher UPA-R positivity, abnormalities of chromosome 11, and M5 FAB morphology may identify a peculiar subset of AML, characterized by a more aggressive clinical course.     

The sorafenib plus nutlin-3 combination promotes synergistic cytotoxicity in acute myeloid leukemic cells irrespectively of FLT3 and p53 status

Background

Both the multi-kinase inhibitor sorafenib and the small molecule inhibitor of the MDM2/p53 interaction, nutlin-3, used alone, have shown promising anti-leukemic activity in acute myeloid leukemia cells. Thus, in this study we investigated the effect of the combination of sorafenib plus nutlin-3 in acute myeloid leukemia.

Design and Methods

Primary acute myeloid leukemia blasts (n=13) and FLT3^wild-type/p53^wild-type (OCI-AML3), FLT3^mutated/p53^wild-type (MOLM), FLT3^mutated/p53^mutated (MV4-11), FLT3^wild-type/p53^deleted (HL60) or FLT3^wild-type/p53^mutated (NB4) acute myeloid cell lines were exposed to sorafenib, used alone or in association with nutlin-3 at a 1:1 ratio, in a range of clinically achievable concentrations (1-10 μM). Induction of apoptosis and autophagy was evaluated by transmission electron microscopy and by specific flow cytometry analyses. The levels of Mcl-1, p53 and Bak proteins were analyzed by western blotting. Knock-down of Bax and Bak gene expression was performed in transfection experiments with specific short interfering RNA.

Results

The sorafenib+nutlin-3 drug combination exhibits synergistic cytotoxicity in primary acute myeloid leukemia blasts and in acute myeloid leukemia cell lines with maximal cytotoxicity in FLT3^mutated MV4-11 and MOLM, followed by the FLT3^wild-type OCI-AML3, HL60 and NB4 cell lines. The cytotoxic activity of sorafenib+nutlin-3 was characterized by an increase of both apoptosis and autophagy. Moreover, Bax and Bak showed prominent roles in mediating the decrease of cell viability in response to the drug combination in p53^wild-type OCI-AML3 and p53^deleted HL-60 cells, respectively, as demonstrated in transfection experiments performed with specific short interfering RNA.

Conclusions

Our data demonstrate that acute myeloid leukemia cells show a variable but overall good susceptibility to the innovative therapeutic combination of sorafenib+nutlin-3, which differentially involves the pro-apoptotic Bcl-2 family members Bax and Bak in p53^wild-type and p53^deleted cells.Key words: sorafenib, nutlin-3, acute myeloid leukemia, p53, apoptosis, autophagy     

Effect of bariatric surgery on peripheral flow-mediated dilation and coronary microvascular function

Background and aimsTo assess the effects of bariatric surgery (BS) on peripheral endothelial function and on coronary microvascular dilator function.Methods and resultsWe studied 50 morbidly obese patients (age 38 ± 9, 13 M) who underwent BS and 20 comparable obese controls (age 41 ± 11, 6 M) without any evidence of cardiovascular disease. Peripheral vascular dilator function was assessed by brachial artery diameter changes in response to post-ischemic forearm hyperaemia (flow-mediated dilation, FMD). Coronary microvascular function was assessed by measuring coronary blood flow (CBF) velocity response to i.v. adenosine and to cold pressor test (CPT) in the left anterior descending coronary artery by transthoracic Doppler echocardiography. The tests were performed at baseline and at 3-month follow-up. At baseline, FMD and CBF response to adenosine and CPT were similar in the 2 groups. Compared to baseline, FMD at follow-up improved significantly in BS patients (5.9 ± 2.7% to 8.8 ± 2.4%, p < 0.01), but not in controls (6.3 ± 3.2% vs. 6.4 ± 3.1%, p = 0.41). Similarly, a significant improvement of CBF response to adenosine (1.63 ± 0.47 to 2.45 ± 0.57, p < 0.01) and to CPT (1.43 ± 0.26 to 2.13 ± 0.55, p < 0.01) was observed in BS patients but not in controls (1.55 ± 0.38 vs. 1.53 ± 0.37, p = 0.85; and 1.37 ± 0.26 vs. 1.34 ± 0.21, p = 0.48, respectively). The favourable vascular effects of BS were similar independently of the presence and changes of other known cardiovascular risk factors and of basal values and changes of serum C-reactive protein levels.ConclusionsOur data show that, in morbidly obese patients, together with peripheral endothelial function, BS also improves coronary microvascular function. These effects suggest global improvement of vascular function which can contribute significantly to the reduction of cardiovascular risk by BS reported in previous studies.     

Association of heart rate variability with arrhythmic events in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia

BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is associated with an increased risk of sudden cardiac death (SCD). Risk stratification of ARVC/D patients, however, remains an unresolved issue. In this study we investigated whether heart rate variability (HRV) can be helpful in identifying ARVC/D patients with increased risk of arrhythmic events. METHODS AND RESULts: We studied 30 consecutive patients (17 males; 45.4 ± 18 years) with ARVC/D, diagnosed according to guideline criteria; 15 patients (50%) had received an implantable cardioverter defibrillator (ICD) for primary SCD prevention. HRV was assessed on 24-h ECG Holter monitoring. The primary endpoint was the occurrence of major arrhythmic events (SCD, sustained ventricular tachycardia (VT), ICD therapy for sustained VT or ventricular fibrillation (VF)). During the follow-up period (19 ± 7 months), no deaths occurred, but 5 patients (17%) experienced arrhythmic events (4 VTs and 1 VF, all in the ICD group). All HRV parameters were significantly lower in patients with, compared with those without, arrhythmic events. Low-frequency amplitude was the most significant HRV variable associated with arrhythmic events in univariate Cox regression analysis (P=0.017), and was the only significant predictor of arrhythmic events in multivariable regression analysis (hazard ratio 0.88, P=0.047), together with unexplained syncope (hazard ratio 16.1, P=0.039). CONCLUSIONS: Our data show that among ARVC/D patients HRV analysis might be helpful in identifying those with increased risk of major arrhythmic events.