Copa Airlines: Study of Non-compliance Causes Based on Audit Findings

Non-compliance is a pressing issue all airlines face. Copa Airlines tasked us with producing findings that would result in a higher understanding of non-compliance causes in their company using audit, employee rotation, delay, and high and low seasonal data. Due to the time limitations of the project we focused on non-compliance in Tocumen International Airport and El Dorado International Airport. Based on our analytical results, recommendations were made to Copa Airlines on how to improve data collection methods for further analysis

Recovery of gastric function in patients affected by chronic atrophic gastritis using L-cysteine (Acetium®): one year survey in comparison with a control group

Background and aim: Chronic Atrophic Gastritis (CAG) is a precancerous condition for gastric cancer (GC) as single risk factor, being a consequence of a previous Helicobacter pylori (Hp) infection or based on autoimmune mechanisms. Achlorhydria plays an important role towards the formation of a class I carcinogen, acetaldehyde, after food intake. L-cysteine has been claimed to be able to bind in a covalent way acetaldehyde when administered at meals. Methods: In this study we enrolled two CAG groups of patients, one treated whit 300 mg/daily of L-cysteine for one year, the other one untreated. We assessed gastric function lasting the one-year follow-up by using noninvasive surrogates, i.e. Pepsinogen I (PGI) and gastrin 17 (G17). Results: In the group of 77 CAG on therapy we found a statistically significant increase in PGI values and a decrease in G17 levels, in comparison with unchanged values in control group. Conclusions: L-cysteine seems able to provide a recovery in gastric function when administered in CAG patients and could be proposed as a possible therapy in such patients. (www.actabiomedica.it)

Probabilistic Bisimulation: Naturally on Distributions

In contrast to the usual understanding of probabilistic systems as stochastic processes, recently these systems have also been regarded as transformers of probabilities. In this paper, we give a natural definition of strong bisimulation for probabilistic systems corresponding to this view that treats probability distributions as first-class citizens. Our definition applies in the same way to discrete systems as well as to systems with uncountable state and action spaces. Several examples demonstrate that our definition refines the understanding of behavioural equivalences of probabilistic systems. In particular, it solves a long-standing open problem concerning the representation of memoryless continuous time by memory-full continuous time. Finally, we give algorithms for computing this bisimulation not only for finite but also for classes of uncountably infinite systems

Barrett’s esophagus: results from an Italian cohort with tight endoscopic surveillance

Background and aim: Barrett’s Esophagus represent a condition that predisposes to the development of esophageal adenocarcinoma. The aim of the present study was to analyze the demographic and clinical characteristics of patients with BE, to establish the presence of risk factors for this condition, and to determine the frequency of dysplastic lesions as well as the evolution towards adenocarcinoma under tight endoscopic control. Methods: In this study, we retrospectively collected and analyzed data from a cohort of patients with Barrett’s Esophagus identified through endoscopic records of ULSS7 in Northern Italy, who underwent upper esophago-gastroduodenoscopy over a 10-year period from July 2008 to December 2020. Results: A total of 264 patients were identified as having BE and included in the study. Mean follow-up was 6.7 years (range: 3 months-13 years). Demographic characteristics of the study population included mean age of 62.7 years (range 33-90 years), with 62.5% of the study population being aged 60 or older, and a male predominance. Females were significantly older than males (65.7 years, range 37-90 vs 61.9 years, range 33-87, p=0.043, respectively). Conclusions: The present study confirms the importance of tight endoscopic control in the management of BE, favoring early detection of BE degeneration towards high grade dysplasia or adenocarcinoma. In a subset of patients with high-risk factors including male sex, cigarette smoking and heavy alcohol intake, it may be worthwhile to consider endoscopic control over time in order to detect the development of BE. (www.actabiomedica.it)

Event structures for the reversible early internal pi-calculus

The pi-calculus is a widely used process calculus, which models com-munications between processes and allows the passing of communication links.Various operational semantics of the pi-calculus have been proposed, which canbe classified according to whether transitions are unlabelled (so-called reductions)or labelled. With labelled transitions, we can distinguish early and late semantics.The early version allows a process to receive names it already knows from the en-vironment, while the late semantics and reduction semantics do not. All existingreversible versions of the pi-calculus use reduction or late semantics, despite theearly semantics of the (forward-only) pi-calculus being more widely used than thelate. We define piIH, the first reversible early pi-calculus, and give it a denotationalsemantics in terms of reversible bundle event structures. The new calculus is a re-versible form of the internal pi-calculus, which is a subset of the pi-calculus whereevery link sent by an output is private, yielding greater symmetry between inputsand outputs

Comparison of HER2 status in primary and paired metastatic sites of gastric carcinoma

Background: Trastuzumab has recently shown efficacy in the treatment of HER2-positive advanced gastric adenocarcinoma. Although antibody-based therapies target the metastatic disease, HER2 status is usually evaluated in the primary tumour because metastatic sites are rarely biopsied. The aim of this study was to compare HER2 status in primary and paired metastatic sites of gastric adenocarcinoma. Methods: The HER2 status was assessed by fluorescence in situ hybridisation (FISH) and immunohistochemistry (IHC) in 72 secondary lesions of gastric adenocarcinoma and in the corresponding primary tumours. Results: Concordance of FISH results, evaluable in 68 primary and matched metastatic sites, was 98.5%. Concordance of IHC results, available in 39 of the 72 paired cases, was 94.9%. Only one case showed discordance between primary tumour and metastasis, being negative by both IHC and FISH in the primary and showing HER2 overexpression and amplification in the corresponding pancreatic lymph node metastasis. Conclusion: The high concordance observed between HER2 results obtained by both IHC and FISH on primary tumours and corresponding metastases suggests that in gastric cancer HER2 status is maintained in most cases unchanged during the metastatic process. Keywords: HER2, gastric cancer, FISH, immunohistochemistr

High levels of Notch intracellular cleaved domain are associated with stemness and reduced bevacizumab efficacy in patients with advanced colon cancer

δ-like ligand 4 (DLL4)-Notch signaling is associated with tumor resistance to anti-vascular endothelial growth factor (VEGF) therapy. Furthermore, Notch signaling is critical for the maintenance of colon cancer stem cells (CSCs), which are relevant in drug resistance and tumor angiogenesis. CD44 is a transmembrane glycoprotein and is considered a putative marker of CSCs. To assess the association of Notch intracellular cleaved domain (NICD), DLL4 and CD44 expression with the efficacy of anti‑angiogenic drugs, a series of samples derived from patients with advanced colon cancer enrolled in prospective clinical trials were analyzed. Histological samples from 51 primary tumors that originated from patients treated with bevacizumab‑based first‑line chemotherapy were analyzed by immunohistochemistry for NICD, DLL4 and CD44 expression, and CD31 for microvessel count. The expression levels of genes relevant for angiogenesis [angiopoietin (ANGPT)1, ANGPT2, fibroblast growth factor (FGF)1, FGF2, epidermal growth factor, placental growth factor, VEGFA and DLL4] were detected by reverse transcription-quantitative PCR using RNA extracte

PTEN status in advanced colorectal cancer treated with cetuximab

BACKGROUND: Loss of phosphatase and tensin homologue deleted in chromosome 10 (PTEN) function in advanced colorectal cancer (CRC) may represent one of the resistance mechanisms to cetuximab by interfering with the epidermal growth factor receptor signal transduction pathway. METHODS: PTEN expression tested by indirect immunofluorescence was evaluated both on primary (n¼43) and on metastatic (n¼24) sites in CRC patients treated with cetuximab. RESULTS: The loss of PTEN expression tested on metastatic sites was negatively associated with response (100% progressive disease (PD) in PTEN-negative cases vs 30% PD in PTEN-positive cases; Po0.05), PFS (0.8 vs 8.2 months; Po0.001) and OS (2.9 vs 14.2 months; Po0.001). CONCLUSION: A potential role of PTEN in the anti-tumour activity of cetuximab could be hypothesised

Biological predictive factors in rectal cancer treated with preoperative radiotherapy or radiochemotherapy

We analysed the expression of microsatellite instability, p53, p21, vascular endothelial growth factor and thymidylate synthase (TS) in pretreatment biopsy specimens from 57 locally advanced rectal cancers. The aim of the study was to correlate the expression of these markers with pathological response. Nineteen patients were treated with preoperative concomitant radiotherapy (RT) and fluorouracil/oxaliplatin-based chemotherapy (RCT), while 38 had RT alone. Pathological complete remission (pCR) and microfoci residual tumour (micR) occurred more frequently in patients treated with RCT (P=0.002) and in N0 tumours (P=0.004). Among patients treated with RCT, high TS levels were associated with a higher response rate (pCR+micR; P=0.015). No such correlation was found in the RT group. The other molecular factors were of no predictive value. Multivariate analysis confirmed a significant interaction between nodal status and the probability of achieving a pathological response (P=0.023) and between TS expression and treatment, indicating that a high TS level is predictive of a higher pathological response in the RCT subset (P=0.007). This study shows that lymph node status is the most important predictive factor of tumour response to preoperative treatment. Thymidylate synthase expression assessed immunohistochemically from pretreatment tumour biopsies may be a useful predictive marker of rectal tumour response to preoperative RCT

Ostomy closure rate during COVID-19 pandemic. An Italian multicentre observational study

During the corona virus disease 2019 (COVID-19) pandemic, most of the surgical procedures were performed for emergencies or oncologic reasons to the detriment of the remaining elective procedures for benign conditions. Ileostomy or colostomy creation are sequelae of oncologic or emergency colorectal surgery, but their closure does not fall within the definition of oncologic or emergency surgery. The aim of this retrospective multicentre observational study is to report the impact of COVID-19 pandemic on the ostomy closure rate in Italy. Data regarding ileostomy and colostomy creation and closure from 24 Italian centres, during the study period (March 2020–February 2021) and during the control period (March 2019–February 2020) were collected. Three hospitals (12.5%) were COVID free. The number of colostomies and ileostomies created and closed in the same period was lower (-18.8% and-30%, respectively) in the study period in comparison to the control period (p = 0.1915 and p = 0.0001, respectively), such as the ostomies closed in the analysed periods but created before (colostomy-36.2% and ileostomy-7.4%, p = 0.2211 and p = 0.1319, respectively). Overall, a 19.5% reduction in ostomies closed occurred in the study period. Based on the present study, a reduction in ostomy closure rate occurred in Italy between March 2020 and February 2021. During the pandemic, the need to change the clinical practice probably prolonged deterioration of quality of life in patients with ostomies, increasing number of stomas that will never be closed, and related management costs, even if these issues have not been investigated in this study