Endovascular treatment of spontaneous isolated abdominal aortic dissection

Isolated abdominal aortic dissection is a rare clinical disease representing only 1.3% of all dissections. There are a few case series reported in the literature. The causes of this pathology can be spontaneous, iatrogenic, or traumatic. Most patients are asymptomatic and symptoms are usually abdominal or back pain, while claudication and lower limb ischemia are rare. Surgical and endovascular treatment are two valid options with acceptable results. We herein describe nine cases of symptomatic spontaneous isolated abdominal aortic dissection, out of which four successfully were treated with an endovascular approach between July 2003 and July 2013. All patients were men, smokers, symptomatic (either abdominal or back pain or lower limb ischemia), with a history of high blood pressure, with a medical history negative for concomitant aneurysmatic dilatation or previous endovascular intervention. Diagnosis of isolated abdominal aortic dissection were established by contrast-enhanced computed tomography angiography (CTA) of the thoracic and abdominal aorta. All nine patients initially underwent medical treatment. In four symptomatic cases, non-responsive to medical therapy, bare-metal stents or stent grafts were successfully positioned. All patients completed a CTA follow-up of at least 12 months, during which they remained symptom-free. Endovascular management of this condition is associated with a high rate of technical success and a low mortality; therefore, it can be considered the treatment of choice when it is feasible

Successful endovascular treatment of a 13 cm abdominal aortic aneurysm. Case report

There is increasing evidence in the literature that endovascular aneurysm repair is the first-line approach for most of abdominal aortic aneurysms (AAAs). Furthermore aortouniiliac stent graft placement is, in high risk patients or during emergency setting, a safe procedure over the mid- and long-term period and compares well with the results of bifurcated stent grafts. We present a case of a 66 -year-old gentleman, with pneumothorax after therapeutic thoracentesis and a giant AAA, successfully treated with an aortomonoiliac stent grafting and femoro-femoral crossover bypass

Pre and postoperative evaluation of transcranial Doppler pulsatility index of the middle cerebral artery in patients with severe carotid artery stenosis

In the management of severe carotid artery stenosis particular importance must be given to the evaluation of the risk of perioperative cerebral ischemic events. Our study analysed the possible relationship between the pre-operative middle cerebral artery Gosling Index, calculated after transcranial Doppler (TCD), and intra-operative stump pressure (SP), in order to identify patients with higher risk of ischemic accidents. Moreover, we studied pre- and post- operative Gosling Index values in association with possible events during follow-up. In a one-year time lapse 47 patients underwent either carotid endoarterectomy (CEA) or carotid artery stenting (CAS) with proximal embolic protection system. All patients were subject to pre- and post-operative TCD with calculation of the Gosling Index and intra-operative SP. We observed that higher pre-operative Gosling Index values are associated with lower intra-operative SP values, elements that represent a higher risk for cerebro-vascular ischemic accidents; this result is particularly evident when observing the diabetic sub-population. An increase in ischemic events did not present statistically significant differences when observing the populations treated with CEA or CAS. TCD and SP are valid and simple exams that can help identify precociously patients with a higher risk of cerebro-vascular accidents related to surgical or endovascular treatment

Arterial stiffness, endothelial and cognitive function in subjects with type 2 diabetes in accordance with absence or presence of diabetic foot syndrome.

BACKGROUND: Endothelial dysfunction is an early marker of cardiovascular disease so endothelial and arterial stiffness indexes are good indicators of vascular health. We aimed to assess whether the presence of diabetic foot is associated with arterial stiffness and endothelial function impairment. METHODS: We studied 50 subjects with type 2 diabetes mellitus and diabetic foot syndrome (DFS) compared to 50 diabetic subjects without diabetic foot, and 53 patients without diabetes mellitus, by means of the mini mental state examination (MMSE) administered to evaluate cognitive performance. Carotid-femoral pulse wave velocity (PWV) and augmentation index (Aix) were also evaluated by Applanation tonometry (SphygmoCor version 7.1), and the RH-PAT data were digitally analyzed online by Endo-PAT2000 using reactive hyperemia index (RHI) values. RESULTS: In comparison to diabetic subjects without diabetic foot the subjects with diabetic foot had higher mean values of PWV, lower mean values of RHI, and lower mean MMSE. At multinomial logistic regression PWV and RHI were significantly associated with diabetic foot presence, whereas ROC curve analysis had good sensitivity and specificity in arterial PWV and RHI for diabetic foot presence. CONCLUSIONS: Pulse wave velocity and augmentation index, mean RHI values, and mean MMSE were effective indicators of diabetic foot. Future research could address these issues by means of longitudinal studies to evaluate cardiovascular event incidence in relation to arterial stiffness, endothelial and cognitive markers

Assessment of heart rate variability (HRV) in subjects with type 2 diabetes mellitus with and without diabetic foot: correlations with endothelial dysfunction indices and markers of adipo-inflammatory dysfunction

Background: Some studies have suggested that patients with diabetes and foot complications have worse cardiovascular and cerebrovascular risk profiles, higher degrees of endothelial dysfunction and arterial stiffness and a higher inflammatory background than patients with diabetes without diabetic foot complications. Patients with diabetes mellitus have an alteration in the sympathovagal balance as assessed by means of heart rate variability (HRV) analysis, which is also related to the presence of endothelial dysfunction. Other studies suggest a possible role of inflammation coexisting with the alteration in the sympathovagal balance in favor of the atherosclerotic process in a mixed population of healthy subjects of middle and advanced age. Aims: The aim of this study was to evaluate the degree of alteration of sympathovagal balance, assessed by HRV analysis, in a cohort of patients with diabetes mellitus with diabetic foot and in control subjects without diabetic foot compared with a population of healthy subjects and the possible correlation of HRV parameters with inflammatory markers and endothelial dysfunction indices. Methods: We enrolled all patients with diabetic ulcerative lesions of the lower limb in the Internal Medicine with Stroke Care ward and of the diabetic foot outpatient clinic of P. Giaccone University Hospital of Palermo between September 2019 and July 2020. 4-h ECG Holter was performed. The following time domain HRV measures were analyzed: average heart rate, square root of the mean of successive differences of NN (RMSSD), standard deviation or square root of the variance (SD), and standard deviation of the means of the NN intervals calculated over a five-minute period (SDANN/5 min). The LF/HF ratio was calculated, reactive hyperemia was evaluated by endo-PAT, and serum levels of vaspine and omentin-1 were assessed by blood sample collection. Results: 63 patients with diabetic foot, 30 patients with diabetes and without ulcerative complications and 30 patients without diabetes were enrolled. Patients with diabetic ulcers showed lower mean diastolic blood pressure values than healthy controls, lower MMSE scores corrected for age, lower serum levels of omentin-1, lower RHI values, higher body weight values and comparable body height values, HF% and LF/HF ratio values. We also reported a negative correlation between the RHI value and HRV indices and the expression of increased parasympathetic activity (RMSDD and HF%) in subjects with diabetic foot and a statistically significant positive correlation with the LF/HF ratio and the expression of the sympathovagal balance. Discussion: Patients with diabetic foot show a higher degree of activation of the parasympathetic system, expressed by the increase in HF values, and a lower LF/HF ratio. Our findings may corroborate the issue that a parasympathetic dysfunction may have a possible additive role in the pathogenesis of other vascular complications in subjects with diabetic foot

Cracking behaviour of high-strength AA2024 aluminium alloy produced by Laser Powder Bed Fusion

Most wrought aluminium alloys of the 2000 series are difficult to manufacture by laser powder bed fusion (L-PBF) due to the formation of cracks during building. To date, the effects of processing regimes on crack formation are still not well understood. In this study we performed a detailed microstructural characterisation of crack development in the AlCuMg alloy AA2024 to quantify the extent of cracking and porosity arising from a range of different process parameters. Two samples, produced with different build parameters, were selected for in-depth study by scanning and transmission electron microscopy; these had similar low levels of porosity but high (H - 2.6 ± 0.4 mm/mm2) and low (L - 1.5 ± 0.3 mm/mm2) crack densities respectively. Based on distinct morphological features and characteristic length, we differentiate hot cracks from solid state cracks. Hot tears form at high angle grain boundaries and are associated with micron-sized gas pores as well as intermetallic phases in both samples. The solidification and cracking behaviour are modelled with the aid of a Scheil-Gulliver model that includes solute trapping. This approach predicts differences in hot-crack-susceptibilities, due to different solidification velocities, in line with experimental observations. The sample H, of high crack density, also experiences the higher cooling rate, and hence strain rate, which contributes to the greater propagation of cold cracks in the low fracture toughness AA2024. The observation of cracking associated with microporosity and the use of a Scheil-based solidification model, including solute trapping, provide new insights into the complex problem of hot tearing during L-PBF

Choice of costimulatory domains and of cytokines determines CAR T-cell activity in neuroblastoma

Chimeric antigen receptor (CAR) T-cell therapy has been shown to be dramatically effective in the treatment of B-cell malignancies. However, there are still substantial obstacles to overcome, before similar responses can be achieved in patients with solid tumors. We evaluated both in vitro and in a preclinical murine model the efficacy of different 2nd and 3rd generation CAR constructs targeting GD2, a disial-ganglioside expressed on the surface of neuroblastoma (NB) tumor cells. In order to address potential safety concerns regarding clinical application, an inducible safety switch, namely inducible Caspase-9 (iC9), was also included in the vector constructs. Our data indicate that a 3rd generation CAR incorporating CD28.4-1BB costimulatory domains is associated with improved anti-tumor efficacy as compared with a CAR incorporating the combination of CD28.OX40 domains. We demonstrate that the choice of 4-1BB signaling results into significant amelioration of several CAR T-cell characteristics, including: 1) T-cell exhaustion, 2) basal T-cell activation, 3) in vivo tumor control and 4) T-cell persistence. The fine-tuning of T-cell culture conditions obtained using IL7 and IL15 was found to be synergic with the CAR.GD2 design in increasing the anti-tumor activity of CAR T cells. We also demonstrate that activation of the suicide gene iC9, included in our construct without significantly impairing neither CAR expression nor anti-tumor activity, leads to a prompt induction of apoptosis of GD2.CAR T cells. Altogether, these findings are instrumental in optimizing the function of CAR T-cell products to be employed in the treatment of children with NB

State pension funds and corporate social responsibility: do beneficiaries’ political values influence funds’ investment decisions?

This study explores the underlying drivers of US public pension funds’ tendency to tilt their portfolios towards companies with stronger corporate social responsibility (CSR). Studying the equity holdings of large, internally-managed US state pension funds, we find evidence that the political leaning of their beneficiaries and political pressures by state politicians affect funds’ investment decisions. State pension funds from states with Democratic-leaning beneficiaries tilt their portfolios more strongly towards companies that perform well on CSR issues, and this tendency is intensified when the state government is dominated by Democratic state politicians. Moreover, we find that funds which tilt their portfolios towards companies with superior CSR scores generate a slightly higher return compared with their counterparts. Overall, our findings indicate that funds align their investment choices with the financial and non-financial interests of their beneficiaries when deciding whether to incorporate CSR into their equity allocations

Female Institutional Directors on Boards and Firm Value

The aim of this research is to examine what impact female institutional directors on boards have on corporate performance. Previous research shows that institutional female directors cannot be considered as a homogeneous group since they represent investors who may or may not maintain business relations with the companies on whose corporate boards they sit. Thus, it is not only the effect of female institutional directors as a whole on firm value that has been analysed, but also the impact of pressure-resistant female directors, who represent institutional investors (investment, pension and mutual funds) that only invest in the company, and do not maintain a business relation with the firm. We hypothesize that there is a non-linear association, specifically quadratic, between institutional and pressure-resistant female directors on boards and corporate performance. Our results report that female institutional directors on boards enhance corporate performance, but when they reach a certain threshold on boards (11.72 %), firm value decreases. In line with female institutional directors, pressure-resistant female directors on boards also increase firm value, but only up to a certain figure (12.71 % on boards), above which they have a negative impact on firm performance. These findings are consistent with an inverted U-shaped relationship between female institutional directors and pressure-resistant female directors and firm performance

Institutional investors and corporate governance

We provide a comprehensive overview of the role of institutional investors in corporate governance with three main components. First, we establish new stylized facts documenting the evolution and importance of institutional ownership. Second, we provide a detailed characterization of key aspects of the legal and regulatory setting within which institutional investors govern portfolio firms. Third, we synthesize the evolving response of the recent theoretical and empirical academic literature in finance to the emergence of institutional investors in corporate governance. We highlight how the defining aspect of institutional investors – the fact that they are financial intermediaries – differentiates them in their governance role from standard principal blockholders. Further, not all institutional investors are identical, and we pay close attention to heterogeneity amongst institutional investors as blockholders