By exploiting the analyticity and boundary value properties of the thermal Green functions that result from the KMS condition in both time and energy complex variables, we treat the general (non-perturbative) problem of recovering the thermal functions at real times from the corresponding functions at imaginary times, introduced as primary objects in the Matsubara formalism. The key property on which we rely is the fact that the Fourier transforms of the retarded and advanced functions in the energy variable have to be the "unique Carlsonian analytic interpolations" of the Fourier coefficients of the imaginary-time correlator, the latter being taken at the discrete Matsubara imaginary energies, respectively in the upper and lower half-planes. Starting from the Fourier coefficients regarded as "data set", we then develop a method based on the Pollaczek polynomials for constructing explicitly their analytic interpolations.

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SummaryBackground : The reason why less than one‐half of patients with gastro‐oesophageal reflux disease develop complicated reflux disease (ulcerative oesophagitis, oesophageal strictures and Barrett's oesophagus) and erosive reflux oesophagitis is not fully understood. Supine nocturnal oesophageal acid reflux is considered to be critically involved in this phenomenon, but reliable data are lacking.Aim : To clarify whether high levels of supine nocturnal oesophageal acid exposure are associated with complicated reflux disease.Methods : Ambulatory 24‐h oesophageal pH monitoring was performed in 220 patients with gastro‐oesophageal reflux disease (56 with complicated reflux disease, 76 with erosive reflux oesophagitis and 88 with non‐erosive reflux disease). The total, supine nocturnal and upright diurnal percentage acid reflux times were calculated.Results : The total percentage acid reflux time was significantly greater in complicated reflux disease than in either erosive reflux oesophagitis (P = 0.024) or non‐erosive reflux disease (P = 0.000). These differences were entirely due to a greater supine nocturnal percentage acid reflux time (P = 0.038 and P = 0.000, respectively), whereas no difference was observed in the upright diurnal percentage acid reflux time.Conclusions : Complicated reflux disease is characterized by high levels of supine nocturnal percentage acid reflux time. Prospective studies would be appropriate to clarify whether the normalization of this parameter is relevant to the effective management of this subset of patients with gastro‐oesophageal reflux disease.

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The concentrations of endogenous amino acids and choline in the extracellular fluid of human cerebral gliomas have been measured, for the first time, by in vivo microdialysis. Glioblastoma growth was associated with increased concentrations of choline, GABA, isoleucine, leucine, lysine, phenylalanine, taurine, tyrosine, and valine. There was no difference between grade III and grade IV tumors in the concentrations of phenylalanine, isoleucine, tyrosine, valine, and lysine, whereas the concentrations of choline, aspartate, taurine, GABA, leucine, and glutamate were significantly different in the two tumor-grade subgroups. In contrast to the other compounds, the concentration of glutamate was decreased in glioma. The parenchyma adjacent to the tumor showed significant changes only in the extracellular concentration of glutamate, isoleucine, and valine. The concentrations of choline and the amino acids, glutamate, leucine, taurine, and tyrosine showed significant positive correlations with the degree of cell proliferation. Epilepsy, which is relatively common in subjects with gliomas, was shown to be a significant confounding variable when the extracellular concentrations of aspartate, glutamate and GABA were considered.