Buparlisib,an oral pan-PI3K inhibitor for the treatment of breast cancer

Introduction: Deregulation of the phosphatidylinositol-3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) intracellular signaling pathway is common in breast cancer (BC) and has been found to be potentially implicated in resistance to endocrine and anti-HER2 therapies. Targeting the PI3K/Akt/mTOR pathway may remove this inhibition and restore sensitivity to these compounds. Buparlisib (BKM120) is a potent oral pan-class I PI3K inhibitor that is being extensively evaluated in multiple tumor types.

Areas covered: This review briefly summarizes the pharmacodynamics and pharmacokinetics of buparlisib, focusing on preclinical and clinical data in BC and on ongoing randomized trials.

Expert opinion: Overall, buparlisib is a safe and tolerable drug and, despite its peculiar toxicity profile, it is suitable for studies in combination with other anticancer agents in BC. Early-phase clinical trials in BC have provided evidence of antitumor activity. Several trials are being conducted in all the biological subsets of BC, including combinations with endocrine therapy, anti-HER2 agents, PARP-inhibitors and chemotherapy. While clinical results are eagerly awaited, biological material suitable for both genomic and non-genomic analyses is being collected. The authors expect an intense investigation of the potential biomarkers that explain response or resistance to buparlisib and inspire strategies to rationally explore the therapeutic potential of this drug.     

p.Arg1809Cys substitution in neurofibromin is associated with a distinctive NF1 phenotype without neurofibromas

Analysis of 786 NF1 mutation-positive subjects with clinical diagnosis of neurofibromatosis type 1 (NF1) allowed to identify the heterozygous c.5425C>T missense variant (p.Arg1809Cys) in six (0.7%) unrelated probands (three familial and three sporadic cases), all exhibiting a mild form of disease. Detailed clinical characterization of these subjects and other eight affected relatives showed that all individuals had multiple cafè-au-lait spots, frequently associated with skinfold freckling, but absence of discrete cutaneous or plexiform neurofibromas, Lisch nodules, typical NF1 osseous lesions or symptomatic optic gliomas. Facial features in half of the individuals were suggestive of Noonan syndrome. Our finding and revision of the literature consistently indicate that the c.5425C>T change is associated with a distinctive, mild form of NF1, providing new data with direct impact on genetic counseling and patient management.     

The changing epidemiology of malaria in Ifakara Town, southern Tanzania

Between 1995 and 2000 there were marked changes in the epidemiology of malaria in Ifakara, southern Tanzania. We documented these changes using parasitological and clinical data from a series of community- and hospital-based studies involving children up to the age of 5 years. There was a right shift and lowering in the age-specific parasite prevalence in the community-based cohort studies. The incidence of clinical malaria in placebo-receiving infants in additional study cohorts dropped from 0.8 in 1995 to 0.43 episodes per infant per year in 2000, an incidence rate ratio of 0.53 (95% confidence interval: 0.404, 0.70, P<0.0001). At the same time, there was an increase in the total number of malaria admissions and a marked right shift in the age pattern of these admissions (median age in 1995 1.55 years vs. 2.33 in 2000, P<0.0001). However, the burden of malaria deaths remained in infants. We discuss how these dramatic changes in the epidemiology of malaria may have arisen from the use of currently available malaria control tools. Caution is required in the interpretation of hospital-based data as it is likely to underestimate the impact of anaemia on mortality in the community, where most paediatric deaths occur. Even in low/moderate malaria transmission settings, where older children suffer most malaria episodes, targeting effective malaria control at infants may produce important reductions in infant mortality caused by malaria.     

Ultrasound evaluation of cortical brain development in fetuses with intrauterine growth restriction

Objective: We evaluated the ultrasound appearance of brain volume and cortical development in fetuses with early growth restriction and placental insufficiency.

Methods: We examined a cohort of 20 fetuses with severe intrauterine growth restriction (IUGR) and evidence of placental insufficiency by three-dimensional (3D) ultrasound between 24 and 34 weeks. We graded cortical development and measured the supratentorial intracranial volume. The cortical grading and volume were compared to data obtained from a reference population of 28 adequate for gestational age (AGA) fetuses.

Results: Ultrasound examinations were performed in 20 fetuses with IUGR. The biometry and brain volume were significantly reduced in IUGR fetuses. There was evidence of accelerated cortical development in IUGR fetuses.

Conclusion: This study confirms that the smaller brain volume in IUGR fetuses, with normal or accelerated cortical maturation as previously depicted with postnatal MRI examination, can be demonstrated by prenatal 3D ultrasound.     

Inhibition of platelet function by injectable isosorbide dinitrate

The possibility that isosorbide dinitrate (ISDN) inhibits platelet function in humans has been explored in vitro and in vivo. Incubation of citrated plateletrich plasma from healthy subjects with scalar concentrations (1.25, 12.5 and 125 μg/ml) of ISDN for 5 and 10 minutes resulted in a decrease in platelet aggregation after ADP, adrenaline, and arachidonic acid at the highest drug concentration (mean decrease: 72% [p < 0.01], 56% [p < 0.05] and 62% [p < 0.05], respectively, with the 10-minute incubation). Also, a significant reduction (30%) in generated thromboxane (TX)B₂ levels was observed after arachidonic acid (p < 0.01). ISDN was then infused at rate of 4 mg/hour for 30 minutes in 11 patients with angina and at a rate of 30 mg/hour for 20 minutes in 8. The smaller dose, which caused minor changes in arterial pressure and heart rate, was accompanied by a marked, significant decrease in ADP- and adrenaline-induced aggregation, with a nadir at 60 minutes from the infusion stop (decreases of 40% and 51% respectively). Circulating platelet aggregates also decreased, with a minimum (? 41%, p < 0.05) at the end of the infusion. The higher infusion rate, causing marked hemodynamic effects, was not accompanied by the occurrence of clear antiplatelet effects. Thus, ISDN can affect platelet function both in vitro and in vivo. The in vivo effect occurs at lower concentrations than in vitro but is blunted when a marked hemodynamic response occurs.     

Intramyocardial dissecting hematoma in anterior wall ST elevation myocardial infarction: impact on left ventricular remodeling and prognosis

Intramyocardial dissecting hematoma is an uncommon complication of myocardial infarction potentially leading to cardiac rupture. The aim of the present study was to investigate coronary reperfusion results, left ventricular (LV) function recovery and remodeling and clinical outcomes in patients with anterior STEMI complicated by intramyocardial hematoma. We prospectively studied 87 patients (mean age 59?±?10 years; 88% male) with anterior STEMI (42 with intramyocardial hematoma) in order to evaluate coronary reperfusion results, LV remodeling (≥15% increase in end-systolic volume) and clinical outcomes (cardiac death, non-fatal reinfarction, and hospitalization for congestive heart failure) at 24 months. Thrombolysis in myocardial infarction (TIMI) flow score and myocardial blush grade (MBG) were assessed both pre- and post-percutaneous coronary intervention (PCI) and speckle-tracking echocardiography was performed post PCI and at 6-month follow-up. Patients with hematoma had lower post-PCI TIMI score and MBG, higher heart rate, worse LV ejection fraction and longitudinal or rotational function than their counterparts. LV remodeling occurred in 33 (78.6%) patients with hematoma and 11 (24.4%) patients without (p?<?0.001). Independent predictors of LV remodeling were heart rate (p?=?0.018), MBG (p?=?0.036) and presence of hematoma (p?<?0.001). Hematoma (log-rank test, χ²?=?9.849; p?=?0.002) and LV remodeling (log-rank test, χ²?=?13.770; p?<?0.001) were associated to a higher rate of adverse events. Cox analysis identified LV remodeling as the only independent predictor of adverse events (hazard ratio?=?3.912; 95% confidence interval, 1.429–10.714; p?=?0.008). Intramyocardial dissecting hematoma complicating anterior STEMI is an independent determinant of LV remodeling and is associated to poor prognosis.     

Assessment of Remote Myocardium Heterogeneity in Patients with Ventricular Tachycardia Using Texture Analysis of Late Iodine Enhancement (LIE) Cardiac Computed Tomography (cCT) Images

Purpose

Diffuse remodeling of myocardial extra-cellular matrix is largely responsible for left ventricle (LV) dysfunction and arrhythmias. Our hypothesis is that the texture analysis of late iodine enhancement (LIE) cardiac computed tomography (cCT) images may improve characterization of the diffuse extra-cellular matrix changes. Our aim was to extract volumetric extracellular volume (ECV) and LIE texture features of non-scarred (remote) myocardium from cCT of patients with recurrent ventricular tachycardia (rVT), and to compare these radiomic features with LV-function, LV-remodeling, and underlying cardiac disease.

Procedures

Forty-eight patients suffering from rVT were prospectively enrolled: 5/48 with idiopathic VT (IVT), 23/48 with post-ischemic dilated cardiomyopathy (ICM), 9/48 with idiopathic dilated cardiomyopathy (IDCM), and 11/48 with scars from a previous healed myocarditis (MYO). All patients underwent echocardiography to assess LV systolic and diastolic function and cCT with pre-contrast, angiographic, and LIE scan to obtain end-diastolic volume (EDV), ECV, and first-order texture parameters of Hounsfield Unit (HU) of remote myocardium in LIE [energy, entropy, HU-mean, HU-median, standard deviation (SD), and mean absolute deviation (MAD)].

Results

Energy, HU mean, and HU median by cCT texture analysis correlated with ECV (rho?=?0.5650, rho?=?0.5741, rho?=?0.5068; p?<?0.0005). cCT-derived ECV, HU-mean, HU-median, SD, and MAD correlated directly to EDV by cCT and inversely to ejection fraction by echocardiography (p?<?0.05). SD and MAD correlated with diastolic function by echocardiography (rho?=?0.3837, p?=?0.0071; rho?=?0.3330, p?=?0.0208). MYO and IVT patients were characterized by significantly lower values of SD and MAD when compared with ICM and IDCM patients, independently of LV-volume systolic and diastolic function.

Conclusions

Texture analysis of LIE may expand cCT capability of myocardial characterization. Myocardial heterogeneity (SD and MAD) was associated with LV dilatation, systolic and diastolic function, and is able to potentially identify the different patterns of structural remodeling characterizing patients with rVT of different etiology.