Deductive Evaluation: Implicit Code Verification With Low User Burden

We describe a framework for symbolically evaluating C code using a deductive approach that discovers and proves program properties. The framework applies Floyd-Hoare verification principles in its treatment of loops, with a library of iteration schemes serving to derive loop invariants. During evaluation, theorem proving is performed on-the-fly, obviating the generation of verification conditions normally needed to establish loop properties. A PVS-based prototype is presented along with results for sample C functions

Deductive Evaluation: Formal Code Analysis With Low User Burden

We describe a framework for symbolically evaluating iterative C code using a deductive approach that automatically discovers and proves program properties. Although verification is not performed, the method can infer detailed program behavior. Software engineering work flows could be enhanced by this type of analysis. Floyd-Hoare verification principles are applied to synthesize loop invariants, using a library of iteration-specific deductive knowledge. When needed, theorem proving is interleaved with evaluation and performed on the fly. Evaluation results take the form of inferred expressions and type constraints for values of program variables. An implementation using PVS (Prototype Verification System) is presented along with results for sample C functions

Recanalization of the Native Artery in Patients with Bypass Failure

Our objective was to evaluate the possible role of endovascular recanalization of occluded native artery after a failed bypass graft in the case of either acute or chronic limb-threatening ischemia otherwise leading to amputation. In a single-center retrospective clinical analysis, from January 2004 to March 2007 we collected 31 consecutive high-surgical-risk patients (32 limbs) with critical limb ischemia following late ([30 days after surgery) failure of open surgery bypass graft reconstruction. All patients deemed unfit for surgery underwent tentative endovascular recanalization of the native occluded arterial tract. The mean follow-up period was 24 (range, 6–42) months. Technical success was achieved in 30 (93.7%) of 32 limbs. The cumulative primary assisted patency calculated by Kaplan–Meyer analysis was 92% and 88%, respectively, at 12 and 24 months. The limb salvage rate approached 90% at 30 months. In conclusion, our experience shows the feasibility of occluded native artery endovascular recanalization after a failed bypass graft, with optimal results in terms of midterm arterial patency and limb salvage. Our opinion is that successful recanalization of the arterial tract previously considered unsuitable for endovascular approach is allowed by improved competency and experience of vascular specialists, as well as the advances made in catheter and guidewire technology. This group of patients would previously have been relegated to repeat bypass grafts, with their inherently inferior patency and recognized added technical demands. We recognize previous surgical native artery disconnection and lack of pedal runoff to be the main cause of technical failure. Keywords Native artery Bypass failure Endovascular recanalizatio

Role of fetal MRI in the evaluation of isolated and non-isolated corpus callosum dysgenesis: results of a cross-sectional study

PURPOSE: The aims of this study were to characterize isolated and non-isolated forms of corpus callosum dysgenesis (CCD) at fetal magnetic resonance imaging (MRI) and to identify early predictors of associated anomalies. METHODS: We retrospectively analyzed 104 fetuses with CCD undergoing MRI between 2006 and 2016. Corpus callosum, cavum septi pellucidi, biometry, presence of ventriculomegaly, gyration anomalies, cranio-encephalic abnormalities and body malformations were evaluated. Results of genetic tests were also recorded. RESULTS: At MRI, isolated CCD was 26.9%, the rest being associated to other abnormalities. In the isolated group, median gestational age at MRI was lower in complete agenesis than in hypoplasia (22 vs 28 weeks). In the group with additional findings, cortical dysplasia was the most frequently associated feature (P = 0.008), with a more frequent occurrence in complete agenesis (70%) versus other forms; mesial frontal lobes were more often involved than other cortical regions (P = 0.006), with polymicrogyria as the most frequent cortical malformation (40%). Multivariate analysis confirmed the association between complete agenesis and cortical dysplasia (odds ratio = 7.29, 95% confidence interval 1.51-35.21). CONCLUSIONS: CCD is often complicated by other intra-cranial and extra-cranial findings (cortical dysplasias as the most prevalent) that significantly affect the postnatal prognosis. The present study showed CCD with associated anomalies as more frequent than isolated (73.1%). In isolated forms, severe ventriculomegaly was a reliable herald of future appearance of associated features

Successful Coronary Stent Retrieval From a Pedal Artery

The purpose of this article is to report complications from a coronary drug-eluting stent lost in the peripheral circulation. We report the case of successful retrieval of a sirolimus coronary stent from a pedal artery in a young patient who underwent coronary angiography for previous anterior myocardial infarction. Recognition of stent embolization requires adequate removal of the device to avoid unwelcome clinical sequelae. Keywords Coronary stent Microsnare technique Peripheral embolization Stent retrieva

B-type natriuretic peptide as a biochemical marker of left ventricular diastolic function: Assessment in asymptomatic patients 1 year after valve replacement for aortic stenosis.

Objectives: Left ventricular (LV) diastolic dysfunction after aortic valve replacement (AVR) carries a substantial risk of development of heart failure and reduced survival. In addition to echocardiography, B-type natriuretic peptide (BNP) provides a powerful incremental assessment of diastolic function. This study evaluates BNP as a marker of LV diastolic dysfunction in a cohort of patients with preserved LV ejection fraction who underwent AVR for pure aortic stenosis and the relationship between BNP values and the grade of LV diastolic dysfunction. Methods A total of 113 patients were included in the study. Echocardiographic evaluation was performed preoperatively, 5 days postoperatively and at 12-month follow-up, to assess LV dimensional and functional parameters. Diastolic function was labelled as normal, mild, moderate or severe dysfunction. Concomitantly, BNP levels were evaluated. Results Mild to severe diastolic dysfunction occurred preoperatively in all patients. At 12-month follow-up, 65 (62.5%) patients had mild and 25 (24.1%) moderate to severe diastolic dysfunction. BNP values, categorized for quartile distribution, correlated with diastolic dysfunction grade (P < 0.001 for each comparison). At receiver operating characteristic analysis, the BNP level of 120 pg/ml was 91% sensitive and 85% specific for diastolic disease, while 300 pg/ml was 80% sensitive and 91% specific for moderate or severe diastolic dysfunction. Twelve months after AVR, BNP values were strongly correlated with the significant echocardiographic parameters suggestive of diastolic dysfunction (P ≤ 0.006 in all cases). Conclusions The BNP level following AVR is related to diastolic disease severity and may complement echocardiographic evaluation when symptoms are unclear and LV function is difficult to interpret

The combination of liver stiffness measurement and NAFLD fibrosis score improves the noninvasive diagnostic accuracy for severe liver fibrosis in patients with nonalcoholic fatty liver disease.

BACKGROUND &amp; AIMS: The accuracy of noninvasive tools for the diagnosis of severe fibrosis in patients with nonalcoholic fatty liver disease(NAFLD) in clinical practice is still limited. We aimed at assessing the diagnostic performance of combined noninvasive tools in two independent cohorts of Italian NAFLD patients. METHODS: We analysed data from 321 Italian patients(179 Sicilian-training cohort, and 142 northern Italy-validation cohort) with an histological diagnosis of NAFLD. Severe fibrosis was defined as fibrosis ≥ F3 according to Kleiner classification. The APRI, AST/ALT, BARD, FIB-4, and NFS scores were calculated according to published algorithms. Liver stiffness measurement(LSM) was performed by FibroScan. Cut-off points of LSM, NFS and FIB-4 for rule-in or rule-out F3-F4 fibrosis were calculated by the reported formulas. RESULTS: In the Sicilian cohort AUCs of LSM, NFS, FIB-4, LSM plus NFS, LSM plus FIB-4, and NFS plus FIB-4 were 0.857, 0.803, 0.790, 0.878, 0.888 and 0.807, respectively, while in the northern Italy cohort the corresponding AUCs were 0.848, 0.730, 0.703, 0.844, 0.850, and 0.733 respectively. In the training cohort, the combination of LSM plus NFS was the best performing strategy, providing false positive, false negative and uncertainty area rates of 0%,1.1% and 48% respectively. Similar results were obtained in the validation cohort with false positive, false negative and uncertainty area rates of 0%,7.3% and 40.8%. CONCLUSIONS: The combination of LSM with NFS, two complementary, easy-to-perform, and widely available tools, is able to accurately diagnose or exclude the presence of severe liver fibrosis, also reducing of about 50-60% the number of needed diagnostic liver biopsies

Comparison between intermediate and severe coronary stenoses and clinical outcomes of an OCT-guided PCI strategy

We compared optical coherence tomography (OCT) features of intermediate and severe coronary stenoses in patients with stable angina and acute coronary syndrome (ACS), and tested the clinical impact of an OCT-based strategy for treating intermediate stenoses