Role of the A(2B) receptor-adenosine deaminase complex in colonic dysmotility associated with bowel inflammation in rats.

BACKGROUND AND PURPOSE: Adenosine A(2B) receptors regulate several physiological enteric functions. However, their role in the pathophysiology of intestinal dysmotility associated with inflammation has not been elucidated. Hence, we investigated the expression of A2B receptors in rat colon and their role in the control of cholinergic motility in the presence of bowel inflammation. EXPERIMENTAL APPROACH: Colitis was induced by 2,4-dinitrobenzenesulfonic acid (DNBS). Colonic A(2B) receptor expression and localization were examined by RT-PCR and immunofluorescence. The interaction between A(2B) receptors and adenosine deaminase was assayed by immunoprecipitation. The role of A(2B) receptors in the control of colonic motility was examined in functional experiments on longitudinal muscle preparations (LMPs). KEY RESULTS: A(2B) receptor mRNA was present in colon from both normal and DNBS-treated rats but levels were increased in the latter. A(2B) receptors were predominantly located in the neuromuscular layer, but, in the presence of colitis, were increased mainly in longitudinal muscle. Functionally, the A(2B) receptor antagonist MRS 1754 enhanced both electrically-evoked and carbachol-induced cholinergic contractions in normal LMPs, but was less effective in inflamed tissues. The A(2B) receptor agonist NECA decreased colonic cholinergic motility, with increased efficacy in inflamed LMP. Immunoprecipitation and functional tests revealed a link between A(2B) receptors and adenosine deaminase, which colocalize in the neuromuscular compartment. CONCLUSIONS AND IMPLICATIONS: Under normal conditions, endogenous adenosine modulates colonic motility via A2B receptors located in the neuromuscular compartment. In the presence of colitis, this inhibitory control is impaired due to a link between A2B receptors and adenosine deaminase, which catabolizes adenosine, thus preventing A(2B) receptor activation.

Cisplatin, gemcitabine and vinorelbine in locally advanced or metastatic non-small-cell lung cancer: a phase I study.

PURPOSE: The objective of this study was to determine the maximally tolerable doses (MTDs) of vinorelbine (VNR) and gemcitabine (GEM) when combined with a fixed dose of cisplatin (CDDP). PATIENTS AND METHODS: Chemotherapy-naive patients with stage IIIB-IV non-small-cell lung cancer (NSCLC) received a fixed dose of CDDP (50 mg/m2) and escalating doses of VNR (starting from 20 mg/m2) and GEM (starting from 800 mg/m2) on days 1 and 8, every three weeks. The single escalation of GEM alone, by 200 mg/m2 at each step, was initially planned up to a dose of 1,200 mg/m2, to be followed by increments of the VNR dose of 5 mg/m2 at each step. RESULTS: Thirty-one patients were enrolled at five different dose levels. The escalation was stopped at level 4 (GEM 1,200 mg/m2 and VNR 25 mg/m2) since two of six patients of this cohort showed dose-limiting neutropenia at treatment cycle 1. Two different dose levels, GEM 1,200 mg/m2 + VNR 20 mg/m2, and GEM 1,000 mg/m2 + VNR 25 mg/m2 were fairly well tolerated. No treatment-related deaths occurred. Neutropenia was the main toxic effect, occurring in 76% of the total of 116 cycles delivered, and in 24% of them was of grades 3 or 4. A total of eight patients (26%) experienced grade 4 neutropenia lasting more than seven days; in five of them it occurred in the first course. Neutropenic fever was observed in four cases. Grade 4 thrombocytopenia occurred in only two patients. Non-hematologic toxicity was a minor problem in all patients but was never dose-limiting. No complete responses were obtained, but sixteen out of 31 (52%) patients achieved partial responses. The median duration of response was 20 (range 6-56+) weeks, while at a nine-month median follow-up, the median survival time has not yet been reached. To date, 18 patients are still alive. The one-year projected survival for all patients was 51%. CONCLUSIONS: Our results show that CDDP, VNR and GEM can be safely given together without substantial reductions in their individual dose intensities. In our opinion, the dose level of GEM 1,000 mg/m2 + VNR 25 mg/m2 given in combination with CDDP 50 mg/m2 on days 1 and 8 of a three-week cycle can be recommended for phase II trials, since it provides a better balance in dose intensity of GEM and VNR. A phase II randomised study is underway to establish the activity of this new regimen (at the above-cited dose level) in chemo-naive NSCLC patients.

[Multifocal cancer of the breast. Considerations on the mammographic diagnosis]. / Il cancero plurifocale della mammella. Considerazioni di diagnostica mammografica.

A review is carried out of a series of mammographic investigations in 687 tumours observed at the Pascale Institute, Naples, between 1972 and 1977. Mammography shows in a high percentage of cases a multifocality of the disease which was unsuspected. This allows a better evaluation of the stage of the tumour and a correct therapeutic programme.