Averaging models: parameters estimation with the R-Average procedure

The Functional Measurement approach, proposed within the theoretical framework of Information Integration Theory (Anderson, 1981, 1982), can be a useful multi-attribute analysis tool. Compared to the majority of statistical models, the averaging model can account for interaction effects without adding complexity. The R-Average method (Vidotto & Vicentini, 2007) can be used to estimate the parameters of these models. By the use of multiple information criteria in the model selection procedure, R-Average allows for the identification of the best subset of parameters that account for the data. After a review of the general method, we present an implementation of the procedure in the framework of R-project, followed by some experiments using a Monte Carlo method(AU)

Initial conditions in the averaging cognitive model

The initial state parameters s0 and w0 are intricate issues of the averaging cognitive models in Information Integration Theory. Usually they are defined as a measure of prior information (Anderson, 1981; 1982) but there are no general rules to deal with them. In fact, there is no agreement as to their treatment except in specific situations such as linear models where they can be merged with the arbitrary zero inter-response scale C0. We present some considerations on their meaning and usefulness in the Functional Measurement approach, starting from different points of view. Furthermore, we suggest a method to deal with their complexity both within each single trial of a factorial design, and between the overall trials of an experiment(AU)

Very low toxicity and good quality of life in 48 elderly patients autotransplanted for hematological malignancies: a single center experience.

Between May 1994 and May 2000, we autotransplanted 48 consecutive patients, 21 females and 27 males aged over 60 years (range: 60-78, median: 63). Sixteen patients had multiple myeloma (MM), 14 high-grade non-Hodgkin's lymphoma (HGNHL), six low-grade non-Hodgkin's lymphoma (LGNHL), nine acute myeloid leukemia (AML), one chronic lymphocytic leukemia (CLL), one Hodgkin's disease (HD) and one breast cancer; the performance status (WHO) was 0-1. Seventeen patients were in 1st CR (35.4%) and one in 2nd CR (2.1%), 25 in PR (52.1%), while five patients had been transplanted with progressive disease (10.4%); seven patients with MM received a double transplant. Patients received high-dose therapy including melphalan alone (13) or associated with other drugs (26), busulfan-cyclophosphamide (three), BEAM (11) and TBI (two). All patients took a median of 11 (range: 8-25) days to reach neutrophils >500/microl, 13 (range: 9-83) days to reach platelets > 20,000/microl and 17 (range: 11-83) days to reach platelets > 50,000/microl. Hematological toxicity, hospital stay and supportive care did not differ from those of a cohort of younger patients. At present, 31 patients are alive (14 in CR, five in PR, five in PD and seven in relapse) and 16 died from PD at a median follow-up of 37 months (1-67). Only one patient died from transplant-related toxicity. Quality of life, evaluated using a QLQ-C30 questionnaire in 25 patients at day +90, was good. In our experience PBPC mobilization and transplantation is feasible in patients aged > or = 60 years and the toxicity of this procedure is acceptable, with an early transplant-related mortality of 1.8%; therefore patients with hematological malignancies potentially curable with high-dose therapy (HDT) should also be candidates for HDT.

Amifostine can reduce mucosal damage after high-dose melphalan conditioning for peripheral blood progenitor cellautotransplant: a retrospective study.

Amifostine (WR-2721; Ethyol) is a well-known cytoprotector, but a possible role in preventing extrahaematological toxicity after high-dose therapy (HDT) has never been investigated. We compared two historical groups of patients who either received (group A, n = 35) or did not receive (group B, n = 33) amifostine (740 mg/m2) before high-dose (HD) melphalan, followed by autologous infusion of peripheral blood progenitor cells (PBPCs). Amifostine was well tolerated at this dose level. Emesis grade 1-2 was the most important side-effect, but the interruption of infusion was never required. The incidence and median duration of severe mucositis (grade 3-4) was 21% and 0 d (range 0-11 d) in group A and 53% and 7 d (range 0-11 d) in group B. The duration of analgesic therapy was also significantly lower in group A (0 d; range 0-12) than in group B (6 d, range 0-20) (P = 0.0001). Severe diarrhoea (3% vs. 25%; P = 0.01) and emesis (9% vs. 34%; P = 0.01) were also reduced in group A in comparison with group B. No differences were observed between the two groups for haematological recovery. This retrospective study strongly suggests that amifostine can reduce severe mucositis and the use of analgesic drugs in this setting. A randomized study is warranted to confirm these preliminary results.

[Cholecystosis: anatomo-clinical profile and therapeutic considerations]. / Le colecistosi. Profilo anatomo-clinico e considerazioni terapeutiche.

In the last 5 years 16 patients with cholecystosis were observed. In this period the most recent diagnostic and therapeutic techniques were used including ultrasound which allowed to diagnose 60% of adenomyomatosis, 33.3% of cholecystosis and 6.7% of gallbladder polyposis. In 6 cases a traditional open surgery cholecystectomy was performed, while the videolaparascopic approach was used in other 6 cases. Histologic examination always confirmed the preoperative diagnosis, however in one case a gallbladder cancer was histologically found; this case had been clinically diagnosed 9 years previously as adenomyomatosis. Therefore, our experience suggest, in agreement with others, that cholecystosis should be considered as a precancerous lesion.

[Current trends in therapeutic indications in gallstones]. / Attuali orientamenti nelle indicazioni terapeutiche per la calcolosi della colecisti.

In the last 3 years, 300 consecutive patients (110 men, 190 women) were treated for gallstone disease using either traditional open surgery or the video laparoscopic approach. The relative clinical data and results were compared and analysed. The Authors conclude that video laparoscopy presents a number of advantages such as minor costs, reduced pain, quick return to work, compared to traditional surgery, especially when correctly indicated.