Peirce on the justification of abduction.

What sort of justification can be claimed for abduction? In this paper we reconstruct Peirce's answer to this question. We show that in his early works on the logic of science Peirce provided an abductive justification of abduction, and that in his mature writings the early solution is enriched by a reference to the place abduction has in a typical scientific inquiry. Since abduction is the first stage of inquiry by which a hypothesis is suggested and which then has to be subjected to inductive testing, the fundamental abduction (ur-abduction) that justifies abduction has also to be subjected to a verification by means of a fundamental induction (ur-induction), namely that the abduction that abduction is valid is verified by an appeal to the history of science.

Multiple Lymph Node Basin Drainage in Trunk Melanoma Is Not Associated with Survival of Sentinel Lymph Node-Positive Patients.

OBJECTIVES: This study was aimed at investigating the prognostic role of multiple lymph node basin drainage (MLBD) in patients with positive sentinel lymph node (SLN) biopsy. BACKGROUND: MLBD is frequently observed in patients with trunk melanoma undergoing SLN. The prognostic value of MLBD in SLN-positive patients is still debated. METHODS: Retrospective data from 312 trunk melanoma patients with positive SLN biopsy (1991-2012) at 6 Italian referral centres were gathered in a multicentre database. MLBD was defined at preoperative lymphoscintigraphy. Clinical and pathological data were analysed for their association with disease-free interval (DFI) and disease-specific (DSS) survival. RESULTS: MLBD was identified in 34.6% of patients (108/312) and was significantly associated with >1 positive SLN (37 vs. 15.2%; p < 0.001) and with >1 positive lymph node (LN) after complete lymph node dissection (CLND) (50.9 vs. 34.8%; p = 0.033). No differences were observed according to drainage pattern in patients who had negative and positive non-SLN at CLND. MLBD was not associated with either DFI or DSS. Multivariate analyses showed that tumour thickness, ulceration, and number of metastatic LNs were associated with worse DFI and DSS, while regression confirmed its protective role in survival. CONCLUSION: In positive SLN patients, MLBD has no association with survival, which is mainly related to American Joint Committee on Cancer (AJCC) prognostic factors. Since the overall number of positive LNs drives the prognosis, the importance of a CLND in all the positive basins is confirmed.

Prognostic Role of Multiple Lymphatic Basin Drainage in Sentinel Lymph Node-Negative Trunk Melanoma Patients: A Multicenter Study from the Italian Melanoma Intergroup.

BACKGROUND: Multiple lymphatic basin drainage (MLBD) is frequently observed in patients with trunk melanoma undergoing sentinel lymph node (SLN) biopsy. Conflicting data regarding the prognostic association of MLBD in SLN-negative patients have been reported. This study aimed to investigate the prognostic role of MLBD in patients with negative SLN biopsy. METHODS: Retrospective data from 656 melanoma patients who underwent a SLN biopsy (1991-2012) at six Italian centers were gathered in a multicenter database. MLBD was defined as lymphoscintigraphic and intraoperative identification of an SLN in more than one nodal basin. Clinical and pathologic variables were recorded and analyzed for their impact on survival. RESULTS: SLN-negative patients with MLBD were at lower risk of melanoma recurrence [hazard ratio (HR) 0.73, P = 0.05) and melanoma-related death (HR 0.68, P = 0.001) independent of common staging features. Multivariable Cox analyses of disease-free interval (DFI) and disease-specific survival (DSS) showed that MLBD maintained a favorable role and ulceration an unfavorable role. Histologic regression was independently associated only with DFI. When survival was stratified according to presence of MLBD, histologic regression and Breslow thickness <2 mm were associated with improved DFI (5-year DFI: 96.9 vs. 66,1 %, respectively; HR 0.48, P < 0.001) and DSS (5-year DSS: 96.7 vs. 71.8 %, respectively; HR 0.52, P = 0.005) compared to patients without these three favorable parameters. CONCLUSIONS: Patients with negative SLN biopsy results have better prognosis when two or more lymphatic basins are identified and analyzed. Further research is required to investigate the mechanisms behind this evidence.

Clinical outcomes and phenotypes of respiratory failure in older subjects admitted to an acute care geriatric hospital ward.

Respiratory failure (RF) is frequent in hospitalized older patients, but was never systematically investigated in large populations of older hospitalized patients. We conducted a retrospective administrative study based on hospitalizations of a Geriatrics Unit regarding 2014, 2015, and 2016. Patients underwent daily screening for hypoxia. Hospital discharge records were coded through a standardized methodology. RF, defined as documented hypoxia on room air, was always coded, whenever present. We investigated how RF affected clinical outcomes, whether RF grouped into specific comorbidity phenotypes, and how phenotypes associated with the outcomes. RF was coded in 48.6% of the 1,810 hospitalizations. RF patients were older and more frequently had congestive heart failure (CHF: 49 vs 23%), chronic obstructive pulmonary disease (COPD: 27 vs 6%), pneumonia (14 vs 4%), sepsis (12 vs 7%), and pleural effusion (6 vs 3%), than non-RF patients. RF predicted longer length of stay (a-Beta 2.05, 95% CI 1.4-2.69; p < 0.001) and higher in-hospital death/intensive care units (ICU) need (aRR 7.12, 5-10.15; p < 0.001) after adjustment for confounders (linear and Poisson regression with robust error variance). Among RF patients, cerebrovascular disease, cancer, electrolyte disturbances, sepsis, and non-invasive ventilation predicted increased, while CHF and COPD predicted decreased in-hospital death/ICU need. The ONCO (cancer) and Mixed (cerebrovascular disease, dementia, pneumonia, sepsis, electrolyte disturbances, bedsores) phenotypes displayed higher in-hospital death/ICU need than CARDIO (CHF) and COPD phenotypes. In this study, RF predicted increased hospital death/ICU need and longer hospital stay, but also reflected diverse underlying conditions and clinical phenotypes that accounted for different clinical courses.

Surface-mediated formation of Pu(IV) nanoparticles at the muscovite-electrolyte interface.

The formation of Pu(IV)-oxo-nanoparticles from Pu(III) solutions by a surface-enhanced redox/polymerization reaction at the muscovite (001) basal plane is reported, with a continuous increase in plutonium coverage observed in situ over several hours. The sorbed Pu extends >70 Å from the surface with a maximum concentration at 10.5 Å and a total coverage of >9 Pu atoms per unit cell area of muscovite (0.77 µg Pu/cm(2)) (determined independently by in situ resonant anomalous X-ray reflectivity and by ex-situ alpha-spectrometry). The presence of discrete nanoparticles is confirmed by high resolution atomic force microscopy. We propose that the formation of these Pu(IV) nanoparticles from an otherwise stable Pu(III) solution can be explained by the combination of a highly concentrated interfacial Pu-ion species, the Pu(III)-Pu(IV) redox equilibrium, and the strong proclivity of tetravalent Pu to hydrolyze and form polymeric species. These results are the first direct observation of such behavior of plutonium on a naturally occurring mineral, providing insights into understanding the environmental transport of plutonium and other contaminants capable of similar redox/polymerization reactions.

A Novel Ex Vivo Approach Based on Proteomics and Biomarkers to Evaluate the Effects of Chrysene, MEHP, and PBDE-47 on Loggerhead Sea Turtles (Caretta caretta).

The principal aim of the present study was to develop and apply novel ex vivo tests as an alternative to cell cultures able to evaluate the possible effects of emerging and legacy contaminants in Caretta caretta. To this end, we performed ex vivo experiments on non-invasively collected whole-blood and skin-biopsy slices treated with chrysene, MEHP, or PBDE-47. Blood samples were tested by oxidative stress (TAS), immune system (respiratory burst, lysozyme, and complement system), and genotoxicity (ENA assay) biomarkers, and genotoxic and immune system effects were observed. Skin slices were analyzed by applying a 2D-PAGE/MS proteomic approach, and specific contaminant signatures were delineated on the skin proteomic profile. These reflect biochemical effects induced by each treatment and allowed to identify glutathione S-transferase P, peptidyl-prolyl cis-trans isomerase A, mimecan, and protein S100-A6 as potential biomarkers of the health-threatening impact the texted toxicants have on C. caretta. Obtained results confirm the suitability of the ex vivo system and indicate the potential risk the loggerhead sea turtle is undergoing in the natural environment. In conclusion, this work proved the relevance that the applied ex vivo models may have in testing the toxicity of other compounds and mixtures and in biomarker discovery.

Efficacy of Electrochemotherapy in the Treatment of Cutaneous Melanoma Metastases and Rare Non-melanoma Skin Cancer.

BACKGROUND: We aimed to verify the clinical efficacy and safety of the electrochemotherapy in melanoma metastases and in cases of rare non-melanoma tumors that were difficult to treat for the specific anatomical site or for patient comorbidities. PATIENTS AND METHODS: We treated 68 patients (699 cutaneous nodules), 44 patients with metastatic melanomas and 24 patients with non-melanoma tumors, at the Melanoma & Skin Cancer Unit, Florence, Italy. RESULTS: We obtained an objective response of 89.7% (88.6% in melanomas and 91.7% in non-melanoma tumors), complete response 54.4% and partial response 35.3%. CONCLUSION: This study showed that electrochemotherapy is effective in the treatment of melanoma metastases and in rare types of non-melanoma tumors. In particular, we successfully treated rare tumors as angiosarcoma, pleomorphic sarcoma, myxofibrosarcoma, sarcoma di Kaposi, porocarcinoma, sebaceous carcinoma, Merkel cell carcinoma, malignant blue nevus, undifferentiated epitheliomorphic cell neoplasia and metastases from thyroid carcinoma. No serious adverse events were observed.

Enhancing the prognostic role of melanoma sentinel lymph nodes through microscopic tumour burden characterization: clinical usefulness in patients who do not undergo complete lymph node dissection.

This study aimed to investigate the sentinel lymph node (SLN) tumour burden to predict the non-SLN positivity rate and the survival of melanoma patients to evaluate whether SLN microstaging could predict the prognosis, similar to what is currently performed by examining the lymph nodes excised by complete lymph node dissection. Of 1130 consecutive melanoma patients who underwent SLN biopsy, 226 were tumour-positive and 204 were included in this study. SLN metastases were classified on the basis of dimensional (Rotterdam) and topographic (Dewar) criteria either separately or combined. SLN metastases more than 1 mm in diameter had the highest non-SLN positivity rate (31%) compared with metastases 0.1-1 mm (10%) and less than 0.1 mm (4%). The non-SLN positivity rate was 45% for extensive metastases, 5% for subcapsular metastases and 23-29% for parenchymal, combined and multifocal classes, therefore suggesting a simplification of the parenchymal SLN metastases into only two classes: extensive and 'not extensive'. The dimension of the metastasis was correlated with a different non-SLN positivity rate only when the metastasis was in the parenchyma (20-36%) and not when it was in the subcapsular location (4-7%). Interestingly, the 5-year melanoma-specific survival (MSS) was 89% for patients with subcapsular less than 0.1 mm metastases and 45% for patients with nonsubcapsular more than 1 mm metastases (P=0.017). In the parenchyma, larger metastases (>1 mm) were related to a lower 5-year MSS (46%) than smaller (<1 mm) metastases (MSS 77%). SLN tumour burden characterization can be simplified and it can provide prognostic information on non-SLN positivity and survival, which is especially useful in patients who do not undergo complete lymph node dissection.

Median Arcuate Ligament Syndrome in a patient with Crohn's disease.

INTRODUCTION: The Median Arcuate Ligament Syndrome is a rare condition characterized by postprandial abdominal pain, bowel function disorder and weight loss. We report the first case to our knowledge of Crohn's disease and Median Arcuate Ligament Syndrome. PRESENTATION OF CASE: The patient was a 33 year-old female with a previous diagnosis of Crohn's disease. Acute postprandial abdominal pain affected the patient every day; she was, therefore, referred to US-Doppler and magnetic resonance angiography of the abdominal vessels and received a diagnosis of Median Arcuate Ligament Syndrome. Consequently, the patient was surgically treated, releasing the vascular compression. After the operation, she reported a complete relief from postprandial pain which was one of her major concerns. Subocclusive symptoms occurred after six months due to the inflammatory reactivation of the terminal ileitis. DISCUSSION: The diagnosis of Median Arcuate Ligament Syndrome is mainly based on the exclusion of other intestinal disorders but it should be always confirmed using noninvasive tests such as US-Doppler, angio-CT or magnetic resonance angiography. CONCLUSION: This case demonstrates that the Median Arcuate Ligament Syndrome could be the major cause of symptoms, even in presence of other abdominal disorders.

Symptomatic duodenal Crohn's disease: is strictureplasty the right choice?

Primary duodenal localization of Crohn's disease (CD) is rare. Medical therapy can control symptoms, but surgery is required when progressive obstructive symptoms occur. Surgical options include bypass, resection, or strictureplasty, but it is still not clear which should be the treatment of choice. Reviewing the medical records of 1253 patients undergoing surgery for CD between January 1986 and December 2011 at the Digestive Surgery Unit of the Department of Clinical Physiopathology of the University of Florence, 10 patients (6 males and 4 females) underwent operations for duodenal CD. Four patients had only a duodenal localization, 6 patients had synchronous involvement of other intestinal tracts. Strictures were distributed in all the duodenal portions: in 7 patients there were single lesions, in 3 patients there were multiple lesions. Eight patients were treated with strictureplasty: 5 with the Heineke-Mikulicz technique, 2 with Jaboulay, and 1 with a pedunculated jejunal patch. Two patients were treated with resection: one with a B2 gastro-duodenal resection, and 1 with a duodenal-jejunal resection and an end to side duodeno-jejunal anastomosis. Follow up of the patients was from 2 to 18 years. No recurrence of duodenal CD was observed in the 2 patients treated with resection, while 2 of the 8 patients treated with strictureplasty had a recurrence. In our experience, strictureplasty is indicated when less than 2 strictures are present in the 2nd or 3rd duodenal portion. In cases with multiple strictures localized in the 1st or the distal duodenal portion, resection is preferable.

A multidisciplinary approach to desmoid tumors. When intra-abdominal fibromatosis degenerates into an abscess, which is the right treatment?

INTRODUCTION: Desmoid tumors are rare benign tumors that originates in the fibrous sheath or musculo-aponeurotic structure. Histologically benign, they tends to invade locally and to be recurrent. PRESENTATION OF CASE: We report a rare case of an intra-abdominal desmoid tumor in a patient affected by familial adenomatous polyposis, which degenerated into abscess. Male, 38 years, was hospitalized for abdominal pain, bowel obstruction and fever. The computed tomography showed a big dishomogeneous mass occupying the whole mesentery with internal massive liquefaction. The mass extended from the epigastrium for 13cm up to L3. On the right mesogastric side a solid, thick mass of about 2cm, with a length of 4.5cm, was identified; it was not cleavable from the wall and from some of the loops. We decided to perform a computed tomography-guided percutaneous drainage. Two hundred ml of purulent necrotic material was aspirated, and washing with antibiotic solution was carried out. Cytological examination of fluid drainage showed histiocytes and neutrophils. At follow-up, the patient's clinical condition had improved. An abdominal ultrasound showed a substantial reduction in the diameter of the mass. DISCUSSION: Diagnosis and treatment of desmoids tumor in patients with familial adenomatous polyposis may be difficult, especially when desmoids are located intra-abdominally and in the mesentery. Seldom will desmoid tumors be complicated by abscess formation. CONCLUSION: The management of desmoids tumors is not easy and the choice of the best treatment may be difficult due to the different possible anatomical presentations.