The \gamma function in quantum theory II. Mathematical challenges and paradoxa

While the square root of Dirac’s [Formula: see text] is not defined in any standard mathematical formalism, postulating its existence with some further assumptions defines a generalized function called [Formula: see text] which permits a quasi-classical treatment of simple systems like the H atom or the 1D harmonic oscillator for which accurate quantum mechanical energies were previously reported. The so-defined [Formula: see text] is neither a traditional function nor a distribution, and it remains to be seen that any consistent mathematical approaches can be set up to deal with it rigorously. A straightforward use of [Formula: see text] generates several paradoxical situations which are collected here. The help of the scientific community is sought to resolve these paradoxa

Synergistic effects of TNF-alpha and melphalan in an isolated limb perfusion model of rat sarcoma: a histopathological, immunohistochemical and electron microscopical study.

Isolated limb perfusion (ILP) with tumour necrosis factor alpha (TNF-alpha) and melphalan has shown impressive results in patients with irresectable soft tissue sarcomas and stage III melanoma of the extremities. The mechanisms of the reported in vivo synergistic anti-tumour effects of TNF-alpha and melphalan are not precisely understood. We have developed an ILP model in the rat using a non-immunogenic sarcoma in which similar in vivo synergy is observed. The aim of this present study was to analyse the morphological substrate for this synergistic response of TNF-alpha in combination with melphalan to shed more light on the pathomechanisms involved. Histology of the tumours from saline- (n = 14) and melphalan-treated (n = 11) rats revealed apparently vital tumour cells in over 80% of the cross-sections. Interstitial oedema and coagulation necrosis were observed in the remaining part of the tumour. Haemorrhage was virtually absent. TNF-alpha (n = 22) induced marked oedema, hyperaemia, vascular congestion, extravasation of erythrocytes and haemorrhagic necrosis (20-60% of the cross-sections). Oedema and haemorrhage suggested drastic alterations of permeability and integrity of the microvasculature. Using light and electron-microscopy, we observed that haemorrhage preceded generalised platelet aggregation. Therefore, we suggest that the observed platelet aggregation was the result of the microvascular damage rather than its initiator. Remarkably, these events hardly influenced tumour growth. However, perfusion with the combination of TNF-alpha and melphalan (n = 24) showed more extensive haemorrhagic necrosis (80-90% of the cross-sections) and revealed a prolonged remission (mean 11 days) in comparison with the other groups of rats. Electron microscopical analysis revealed similar findings as described after TNF-alpha alone, although the effects were more prominent at all time points after perfusion. In conclusion, our findings suggest that the enhanced anti-tumour effect after the combination of TNF-alpha with melphalan results from potentiation of the TNF-alpha-induced vascular changes accompanied by increased vascular permeability and platelet aggregation. This may result in additive cytotoxicity or inhibition of growth of residual tumour cells

A behavioural intervention increases physical activity in people with subacute spinal cord injury: a randomised trial

AbstractQuestions: For people with subacute spinal cord injury, does rehabilitation that is reinforced with the addition of a behavioural intervention to promote physical activity lead to a more active lifestyle than rehabilitation alone? Design: Randomised, controlled trial with concealed allocation, intention-to-treat analysis, and blinded assessors. Participants: Forty-five adults with subacute spinal cord injury who were undergoing inpatient rehabilitation and were dependent on a manual wheelchair. The spinal cord injuries were characterised as: tetraplegia 33%; motor complete 62%; mean time since injury 150 days (SD 74). Intervention: All participants received regular rehabilitation, including handcycle training. Only the experimental group received a behavioural intervention promoting an active lifestyle after discharge. This intervention involved 13 individual sessions delivered by a coach who was trained in motivational interviewing; it began 2 months before and ended 6 months after discharge from inpatient rehabilitation. Outcome measures: The primary outcome was physical activity, which was objectively measured with an accelerometer-based activity monitor 2 months before discharge, at discharge, and 6 and 12 months after discharge from inpatient rehabilitation. The accelerometry data were analysed as total wheeled physical activity, sedentary time and motility. Self-reported physical activity was a secondary outcome. Results: The behavioural intervention significantly increased wheeled physical activity (overall between-group difference from generalised estimating equation 21minutes per day, 95% CI 8 to 35). This difference was evident 6 months after discharge (28minutes per day, 95% CI 8 to 48) and maintained at 12 months after discharge (25minutes per day, 95% CI 1 to 50). No significant intervention effect was found for sedentary time or motility. Self-reported physical activity also significantly improved. Conclusion: The behavioural intervention was effective in eliciting a behavioural change toward a more active lifestyle among people with subacute spinal cord injury. Trial registration: NTR2424. [Nooijen CFJ, Stam H, Bergen MP, Bongers-Janssen HMH, Valent L, van Langeveld S, Twisk J, Act-Active Research Group, van den Berg-Emons RJG (2016) A behavioural intervention increases physical activity in people with subacute spinal cord injury: a randomised trial. Journal of Physiotherapy 62: 35–41

The effectiveness and satisfaction of web-based physiotherapy in people with spinal cord injury: a pilot randomised controlled trial

Study Design: Pilot randomised controlled trial. Objectives: The aims of this study were to evaluate the effectiveness and participant satisfaction of web-based physiotherapy for people with Spinal Cord Injury (SCI). Setting: Community patients of a national spinal injury unit in a university teaching hospital, Scotland, UK. Methods: Twenty-four participants were recruited and randomised to receive eight weeks of web-based physiotherapy (intervention), twice per week, or usual care (control). Individual exercise programmes were prescribed based upon participant’s abilities. The intervention was delivered via a website (www.webbasedphysio.com) and monitored and progressed remotely by the physiotherapist. Results: Participants logged on to the website an average of 1.4±0.8 times per week. Between-group differences, although not significant were more pronounced for the 6 minute walk test. Participants were positive about using web-based physiotherapy and stated they would be happy to use it again and would recommend it to others. Overall it was rated as either good or excellent. Conclusions: Web-based physiotherapy was feasible and acceptable for people with SCI. Participants achieved good compliance with the intervention, rated the programme highly and beneficial for health and well-being at various states post injury. The results of this study warrant further work with a more homogenous sample

The Influence of Hepatic Steatosis and Fibrosis on Postoperative Outcomes After Major Liver Resection of Perihilar Cholangiocarcinoma

Background: Surgical resection for perihilar cholangiocarcinoma (pCCA) is associated with high operative risks. Impaired liver regeneration in patients with pre-existing liver disease may contribute to posthepatectomy liver failure (PHLF) and postoperative mortality. This study aimed to determine the incidence of hepatic steatosis and fibrosis and their association with PHLF and 90-day postoperative mortality in pCCA patients. Methods: Patients who underwent a major liver resection for pCCA were included in the study between 2000 and 2021 from three tertiary referral hospitals. Histopathologic assessment of hepatic steatosis and fibrosis was performed. The primary outcomes were PHLF and 90-day mortality. Results: Of the 401 included patients, steatosis was absent in 334 patients (83.3%), mild in 58 patients (14.5%) and moderate to severe in 9 patients (2.2%). There was no fibrosis in 92 patients (23.1%), periportal fibrosis in 150 patients (37.6%), septal fibrosis in 123 patients (30.8%), and biliary cirrhosis in 34 patients (8.5%). Steatosis (≥ 5%) was not associated with PHLF (odds ratio [OR] 1.36; 95% confidence interval [CI] 0.69–2.68) or 90-day mortality (OR 1.22; 95% CI 0.62–2.39). Neither was fibrosis (i.e., periportal, septal, or biliary cirrhosis) associated with PHLF (OR 0.76; 95% CI 0.41–1.41) or 90-day mortality (OR 0.60; 95% CI 0.33–1.06). The independent risk factors for PHLF were preoperative cholangitis (OR 2.38; 95% CI 1. 36–4.17) and future liver remnant smaller than 40% (OR 2.40; 95% CI 1.31–4.38). The independent risk factors for 90-day mortality were age of 65 years or older (OR 2.40; 95% CI 1.36–4.23) and preoperative cholangitis (OR 2.25; 95% CI 1.30–3.87). Conclusion: In this study, no association could be demonstrated between hepatic steatosis or fibrosis and postoperative outcomes after resection of pCCA.</p

Preoperative endoscopic biliary drainage by metal versus plastic stents for resectable perihilar cholangiocarcinoma

Background and Aims: Adequate preoperative biliary drainage (PBD) is recommended in most patients with resectable perihilar cholangiocarcinoma (pCCA). Most expert centers use endoscopic plastic stents rather than self-expandable metal stents (SEMSs). In the palliative setting, however, use of SEMSs has shown longer patency and superior survival. The aim of this retrospective study was to compare stent dysfunction of SEMSs versus plastic stents for PBD in resectable pCCA patients. Methods:In this multicenter international retrospective cohort study, patients with potentially resectable pCCAs who underwent initial endoscopic PBD from 2010 to 2020 were included. Stent failure was a composite end point of cholangitis or reintervention due to adverse events or insufficient PBD. Other adverse events, surgical outcomes, and survival were recorded. Propensity score matching (PSM) was performed on several baseline characteristics. Results: A total of 474 patients had successful stent placement, of whom 61 received SEMSs and 413 plastic stents. PSM (1:1) resulted in 2 groups of 59 patients each. Stent failure occurred significantly less in the SEMSs group (31% vs 64%; P &lt; .001). Besides less cholangitis after SEMSs placement (15% vs 31%; P = .012), other PBD-related adverse events did not differ. The number of patients undergoing surgical resection was not significantly different (46% vs 49%; P = .71). Complete intraoperative SEMSs removal was successful and without adverse events in all patients. Conclusions: Stent failure was lower in patients with SEMSs as PBD compared with plastic stents in patients with resectable pCCA. Removal during surgery was quite feasible. Surgical outcomes were similar.</p

In vivo isolated kidney perfusion with tumour necrosis factor α (TNF-α) in tumour-bearing rats

Isolated perfusion of the extremities with high-dose tumour necrosis factor α (TNF-α) plus melphalan leads to dramatic tumour response in patients with irresectable soft tissue sarcoma or multiple melanoma in transit metastases. We developed in vivo isolated organ perfusion models to determine whether similar tumour responses in solid organ tumours can be obtained with this regimen. Here, we describe the technique of isolated kidney perfusion. We studied the feasibility of a perfusion with TNF-α and assessed its anti-tumour effects in tumour models differing in tumour vasculature. The maximal tolerated dose (MTD) proved to be only 1 μg TNF-α. Higher doses appeared to induce renal failure and a secondary cytokine release with fatal respiratory and septic shock-like symptoms. In vitro, the combination of TNF-α and melphalan did not result in a synergistic growth-inhibiting effect on CC 531 colon adenocarcinoma cells, whereas an additive effect was observed on osteosarcoma ROS-1 cells. In vivo isolated kidney perfusion, with TNF-α alone or in combination with melphalan, did not result in a significant anti-tumour response in either tumour model in a subrenal capsule assay. We conclude that, because of the susceptibility of the kidney to perfusion with TNF-α, the minimal threshold concentration of TNF-α to exert its anti-tumour effects was not reached. The applicability of TNF-α in isolated kidney perfusion for human tumours seems, therefore, questionable. © 1999 Cancer Research Campaig