Giuseppe Curcurù

A predictive maintenance policy with imperfect monitoring

For many systems, failure is a very dangerous or costly event. To reduce the occurrence of this event, it is necessary to implement a preventive maintenance policy to replace the critical elements before failure. Since elements do not often exhibit incipient faults, they are replaced before a complete exploiting of their useful life. To conjugate the objective of exploiting elements for almost all their useful life with the objective to avoid failure, condition based and, more recently, predictive maintenance policies have been proposed. This paper deals with this topic and proposes a procedure for the computation of the maintenance time that minimizes the global maintenance cost. By adopting a stochastic model for the degradation process and by hypothesizing the use of an imperfect monitoring system, the procedure updates by a Bayesian approach, the a-priori information, using the data coming from the monitoring system. The convenience in adopting the proposed policy, with respect to the classical preventive one, is explored by simulation, showing how it depends on some parameters characterizing the problem.

Heat Shock Protein 60 Levels in Tissue and Circulating Exosomes in Human Large Bowel Cancer Before and After Ablative Surgery

Heat shock protein 60 (Hsp60) is a chaperonin involved in tumorigenesis, but its participation in tumor development and progression is not well understood and its value as a tumor biomarker has not been fully elucidated. In the current study, the authors presented evidence supporting the theory that Hsp60 has potential as a biomarker as well as a therapeutic target in patients with large bowel cancer.

Modeling of Hepatocytes Proliferation Isolated from Proximal and Distal Zones from Human Hepatocellular Carcinoma Lesion

Isolation of hepatocytes from cirrhotic human livers and subsequent primary culture are important new tools for laboratory research and cell-based therapeutics in the study of hepatocellular carcinoma (HCC). Using such techniques, we have previously identified different subpopulations of human hepatocytes and among them one is showing a progressive transformation of hepatocytes in HCC-like cells. We have hypothesized that increasing the distance from the neoplastic lesion might affect hepatocyte function and transformation capacity. However, limited information is available in comparing the growth and proliferation of human hepatocytes obtained from different areas of the same cirrhotic liver in relation to their distance from the HCC lesion. In this study, hepatocytes from 10 patients with cirrhosis and HCC undergoing surgical resections from specimens obtained at a proximal (CP) and distal (CD) distance from the HCC lesion were isolated and placed in primary culture. CP hepatocytes (CP-Hep) were isolated between 1 to 3 cm (leaving at least 1cm margin to avoid cancer cells and/or satellite lesions), while CD hepatocytes (CD-Hep) were isolated from more than 5 cm or from the contralateral-lobe. A statistical model was built to analyze the proliferation rates of these cells and we evaluated expression of HCC markers (Glypican-3 (GPC3), αSmooth Muscle Actin (α-SMA) and PCNA). We observed a significant difference in proliferation and in-vitro growth showing that CP-Hep had a proliferation pattern and rate significantly different than CD-Hep. Based on these data, this model can provide information to predict growth of human hepatocytes in primary culture in relation to their pre-cancerous state with significant differences in the HCC markers expression. This model provides an important innovative tool for in-vitro analysis of HCC.

Hazardous air pollutants and primary liver cancer in Texas

The incidence of hepatocellular carcinoma (HCC), the most common primary liver cancer, is increasing in the US and tripled during the past two decades. The reasons for such phenomenon remain poorly understood. Texas is among continental states with the highest incidence of liver cancer with an annual increment of 5.7%. Established risk factors for HCC include Hepatitis B and C (HBV, HCV) viral infection, alcohol, tobacco and suspected risk factors include obesity and diabetes. While distribution of these risk factors in the state of Texas is similar to the national data and homogeneous, the incidence of HCC in this state is exceptionally higher than the national average and appears to be dishomogeneous in various areas of the state suggesting that other non-recognized risk factors might play a role. No population-based studies are currently available investigating the effect of exposure to Hazardous Air Pollutants (HAPs) as a contributing risk factor for liver cancer. Incidence rate of liver cancer in Texas by counties for the time period between 2002 and 2012 was obtained from the Texas Cancer Registry (TCR). Through Principal Component Analysis (PCA) a subgroup of pollutants, explaining almost all the dataset variability, were identified and used to cluster Texas counties. The analysis generated 4 clusters showing liver cancer rate either higher or lower than national average in association with either high or low levels of HAPs emission in the environment. The study shows that the selected relevant HAPs, 10 among 253 analyzed, produce a significant correlation (P = 0.01–0.05) and some of these have been previously identified as carcinogens. An association between the increased production and consequent exposure to these HAPs and a higher presence of liver cancer in certain counties is suggested. This study provides a new insight on this complex multifactorial disease suggesting that environmental substances might play a role in the etiology of this cancer.

Current Practices in the Management of Pulmonary Ground-Glass Opacities: A Survey of SICT Members

BACKGROUNDnSeveral gray areas and controversies exist concerning the management of pulmonary ground-glass opacities (GGOs), and there is a lack of consensus among clinicians on this topic. One of the main aims of the Italian Society of Thoracic Surgery is to promote education and research, so we decided to perform a survey on this topic to estimate current trends in practice in a large sample of thoracic surgeons.nnnMETHODSnA total of 160 thoracic surgeons responded, namely, completed our questionnaire (response rate, 53%; 160 of 302). The survey was composed of 36 questions divided into six subsections: (1) demographic characteristics of the respondents; (2) terminology andxa0taxonomy; (3) radiologic and radiometabolic evaluation; (4) diagnostic approach and indications for surgery; (5) surgical management; and (6) radiologic surveillance.nnnRESULTSnWe observed some divergence of opinion regarding the definition of mixed GGOs, the role of 18F fluorodeoxyglucose positron emission tomography and computed tomography scans, indications for nonsurgical biopsy, intraoperative techniques for localizing GGOs, indications for surgery, extension of lung resection and lymph node dissection according to the radiologic scenario, use of intraoperative frozen section analysis, and radiologic surveillance of pure GGOs.nnnCONCLUSIONSnThis topic warrants more investigation in the future. An upcoming consensus conference of Italian Society of Thoracic Surgery experts (also open to experts in other specialties) could provide updated indications for GGO management based on the literature, expert opinions, and the results of the present survey.