The Seiberg-Witten Map for Noncommutative Gauge Theories

The Seiberg-Witten map for noncommutative Yang-Mills theories is studied and methods for its explicit construction are discussed which are valid for any gauge group. In particular the use of the evolution equation is described in some detail and its relation to the cohomological approach is elucidated. Cohomological methods which are applicable to gauge theories requiring the Batalin-Vilkoviskii antifield formalism are briefly mentioned. Also, the analogy of the Weyl-Moyal star product with the star product of open bosonic string field theory and possible ramifications of this analogy are briefly mentioned.Comment: 12 pages, talk presented at "Continuous Advances in QCD 2002/Arkadyfest", University of Minnesota, Minneapolis, May 17-23, 2002. A few misprints correcte

Model-informed repurposing of medicines for SARS-CoV-2: extrapolation of antiviral activity and dose rationale for paediatric patients

Repurposing of remdesivir and other drugs with potential antiviral activity has been the basis of numerous clinical trials aimed at SARS-CoV-2 infection in adults. However, expeditiously designed trials without careful consideration of dose rationale have often resulted in treatment failure and toxicity in the target patient population, which includes not only adults but also children. Here we show how paediatric regimens can be identified using pharmacokinetic-pharmacodynamic (PKPD) principles to establish the target exposure and evaluate the implications of dose selection for early and late intervention. Using in vitro data describing the antiviral activity and published pharmacokinetic data for the agents of interest, we apply a model-based approach to assess the exposure range required for adequate viral clearance and eradication. Pharmacokinetic parameter estimates were subsequently used with clinical trial simulations to characterise the probability target attainment (PTA) associated with enhanced antiviral activity in the lungs. Our analysis shows that neither remdesivir, nor anti-malarial drugs can achieve the desirable target exposure range based on a mg/kg dosing regimen, due to a limited safety margin and high concentrations needed to ensure the required PTA. To date, there has been limited focus on suitable interventions for children affected by COVID-19. Most clinical trials have defined doses selection criteria empirically, without thorough evaluation of the PTA. The current results illustrate how model-based approaches can be used for the integration of clinical and nonclinical data, providing a robust framework for assessing the probability of pharmacological success and consequently the dose rationale for antiviral drugs for the treatment of SARS-CoV-2 infection in children

Dose rationale for amoxicillin in neonatal sepsis when referral is not possible

Background: Despite the widespread use of amoxicillin in young children, efforts to establish the feasibility of simplified dosing regimens in resource-limited settings have relied upon empirical evidence of efficacy. Given the antibacterial profile of beta-lactams, understanding of the determinants of pharmacokinetic variability may provide a more robust guidance for the selection of a suitable regimen. Here we propose a simplified dosing regimen based on pharmacokinetic-pharmacodynamic principles, taking into account the impact of growth, renal maturation and disease processes on the systemic exposure to amoxicillin. Materials and Methods: A meta-analytical modeling approach was applied to allow the adaptation of an existing pharmacokinetic model for amoxicillin in critically ill adults. Model parameterization was based on allometric concepts, including a maturation function. Clinical trial simulations were then performed to characterize exposure, as defined by secondary pharmacokinetic parameters (AUC, Cmax, Cmin) and T>MIC. The maximization of the T>MIC was used as criterion for the purpose of this analysis and results compared to current WHO guidelines. Results: A two-compartment model with first order absorption and elimination was found to best describe the pharmacokinetics of amoxicillin in the target population. In addition to the changes in clearance and volume distribution associated with demographic covariates, our results show that sepsis alters drug distribution, leading to lower amoxicillin levels and longer half-life as compared to non-systemic disease conditions. In contrast to the current WHO guidelines, our analysis reveals that amoxicillin can be used as a fixed dose regimen including two weight bands: 125 mg b.i.d. for patients with body weight < 4.0 kg and 250 mg b.i.d. for patients with body weight ≥ 4.0 kg. Conclusions: In addition to the effect of developmental growth and renal maturation, sepsis also alters drug disposition. The use of a model-based approach enabled the integration of these factors when defining the dose rationale for amoxicillin. A simplified weight-banded dosing regimen should be considered for neonates and young infants with sepsis when referral is not possible

Combining triple therapy and pulmonary rehabilitation in patients with advanced COPD: a pilot study.

BACKGROUND: The synergistic interactions between pharmacotherapy and pulmonary rehabilitation has been provided, but it remains to be established whether this may also apply to more severe patients. OBJECTIVES: We have examined whether tiotropium enhances the effects of exercise training in patients with advanced COPD (FEV(1)</=60% predicted, hypoxemia at rest corrected with oxygen supplementation, and limitations of physical activity). METHODS: We enrolled 22 patients that were randomised to tiotropium 18mug or placebo inhalation capsules taken once daily. Both groups (11 patients in each group) underwent an in patient pulmonary rehabilitation program and were under regular treatment with salmeterol/fluticasone twice daily. Each rehabilitation session was held 5 days per week (3h/day) for a total of 4 weeks. RESULTS: Compared to placebo, tiotropium had larger impact on pulmonary function (FEV(1)+0.164L, FVC +0.112L, RV -0.544L after tiotropium, FEV(1)+0.084L, FVC -0.039L, RV -0.036L after placebo). The addition of tiotropium allowed a longer distance walked in 6min (82.3m vs. 67.7m after placebo) and reduced dyspnoea (Borg score) (-0.4 vs. +0.18 after placebo) when compared with baseline (pre pulmonary rehabilitation program). The changes in SGRQ from baseline to the end of treatment were: total score -28.3U, activity -27.8U, impact -14.5U, and symptoms -33.4U in the placebo group; and total score -19.1U, activity -18.9U, impact -16.4U, and symptoms -33.8U in the tiotropium group. CONCLUSIONS: Our study clearly indicates that there is an advantage in combining pulmonary rehabilitation with an aggressive drug therapy in more severe patient

Combining triple therapy and pulmonary rehabilitation in patients with advanced COPD: a pilot study.

BACKGROUND: The synergistic interactions between pharmacotherapy and pulmonary rehabilitation has been provided, but it remains to be established whether this may also apply to more severe patients. OBJECTIVES: We have examined whether tiotropium enhances the effects of exercise training in patients with advanced COPD (FEV(1)</=60% predicted, hypoxemia at rest corrected with oxygen supplementation, and limitations of physical activity). METHODS: We enrolled 22 patients that were randomised to tiotropium 18mug or placebo inhalation capsules taken once daily. Both groups (11 patients in each group) underwent an in patient pulmonary rehabilitation program and were under regular treatment with salmeterol/fluticasone twice daily. Each rehabilitation session was held 5 days per week (3h/day) for a total of 4 weeks. RESULTS: Compared to placebo, tiotropium had larger impact on pulmonary function (FEV(1)+0.164L, FVC +0.112L, RV -0.544L after tiotropium, FEV(1)+0.084L, FVC -0.039L, RV -0.036L after placebo). The addition of tiotropium allowed a longer distance walked in 6min (82.3m vs. 67.7m after placebo) and reduced dyspnoea (Borg score) (-0.4 vs. +0.18 after placebo) when compared with baseline (pre pulmonary rehabilitation program). The changes in SGRQ from baseline to the end of treatment were: total score -28.3U, activity -27.8U, impact -14.5U, and symptoms -33.4U in the placebo group; and total score -19.1U, activity -18.9U, impact -16.4U, and symptoms -33.8U in the tiotropium group. CONCLUSIONS: Our study clearly indicates that there is an advantage in combining pulmonary rehabilitation with an aggressive drug therapy in more severe patient

Rapid onset of bronchodilation with formoterol/beclomethasone Modulite and formoterol/budesonide Turbuhaler as compared to formoterol alone in patients with COPD

In the present study, we examined whether there is a difference in the onset of bronchodilatation between formoterol/beclomethasone 12/200 μg Modulite and formoterol/budesonide 9/320 μg Turbuhaler in patients with COPD. We enrolled 28 patients with stable COPD. Both formoterol/beclomethasone and formoterol/budesonide elicited a larger mean FEV1–AUC0−15min than formoterol alone, whereas there was no significant difference between their FEV1–AUC0−15min. Also the change in FEV1 15 min after inhalation of formoterol/beclomethasone combination or formoterol/budesonide combination was greater than that induced by formoterol alone. This study confirms the rapid effect of the inhaled corticosteroid component when combined with formoterol and indicates that the onset of bronchodilation of formoterol/beclomethasone Modulite and formoterol/budesonide Turbuhaler are similar and greater than formoterol alone in patients with COPD

Prediction of lung exposure to anti-tubercular drugs using plasma pharmacokinetic data: implications for dose selection

The development of novel candidate molecules for tuberculosis remains challenging, as drug distribution into the target tissue is not fully characterised in preclinical models of infection. Often antitubercular human dose selection is derived from pharmacokinetic data in plasma. Here, we explore whether whole-body physiologically-based pharmacokinetic (PBPK) modelling enables the prediction of lung exposure to anti-tubercular drugs in humans. Whole-body PBPK models were developed for rifampicin, isoniazid, pyrazinamide, and ethambutol using plasma data in mice as basis for the prediction of lung exposure. Model parameters were subsequently used to extrapolate disposition properties from mouse and determine lung:plasma ratio in humans. Model predictions were compared to biopsy data from patients. Predictions were deemed adequate if they fell within two-fold range of the observations. The concentration vs time profiles in lung were adequately predicted in mice. Isoniazid and pyrazinamide lung exposures were predicted to be comparable to plasma levels, whereas ethambutol lung exposure was predicted to be higher than in plasma. Lung:plasma ratio in humans could be reasonably predicted from preclinical data, but was highly dependent on the distribution model. This analysis showed that plasma pharmacokinetics may be used in conjunction with PBPK modelling to derive lung tissue exposure in mice and humans during early lead optimisation phase. However, the impact of uncertainty in predicted tissue exposure due to distribution should be always investigated through a sensitivity analysis when only plasma data is available. Despite these limitations, insight into lung tissue distribution represents a critical step for the dose rationale in tuberculosis patients

A Cohomological Approach to the Non-Abelian Seiberg-Witten Map

We present a cohomological method for obtaining the non-Abelian Seiberg-Witten map for any gauge group and to any order in theta. By introducing a ghost field, we are able to express the equations defining the Seiberg-Witten map through a coboundary operator, so that they can be solved by constructing a corresponding homotopy operator.Comment: 18 pages. References added and some misprints correcte

Two cases study of fouling colonization patterns in the Mediterranean Sea in the perspective of integrated aquaculture systems

Fouling assemblage colonizing fish-farms is considered mostly to produce negative impacts causing financial loss. By contrast, large evidences emerged on the bioremediation role by biofouling associated to aquaculture facilities, even if the fouling assemblages thriving in the water column was poorly investigated. The aim of the present work was to investigate the macrofouling assemblages over one year of immersion, in order to single out the fouling species, which play the most remarkable role for the bioremediation of the marine areas affected by aquaculture activities. With this in mind, we studied the fouling community dynamics in two Mediterranean maricultural facilities, respectively in the Mar Grande of Taranto (Ionian Sea) and in the Gulf of Gaeta (Tyrrhenian Sea), using the same experimental design and time frame. Two experiments were carried out using artificial panels anchored to two finfish cages. The one-year old fouling communities in the two sites were compared at four seasons of immersion, four submersion durations and three depths, both communities from structural and functional points of view. Notwithstanding the quite similar species composition of fouling of the two sites, the biofouling showed the highest biodiversity in the Mar Grande of Taranto. In the Gulf of Gaeta mussels, Mytilus galloprovincialis, dominated at all the times and depths, whilst in the Mar Grande of Taranto they were especially abundant at the surface with the deepest panels being largely colonized by polychaete sabellids. The co-occurrence of the filter-feeders Mytilus-sabellids recorded in the Gulf of Taranto also highlighted the highest filtration capability. Our results suggest two different fouling assemblages as candidates for bioremediation in integrated multitrophic aquaculture facilities: both a monospecific system dominated by mussels and a multi-specific system with sabellids and mussels as most abundant filter-feeders