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Biomedical subjects

G Vignati

Publications and source records attributed to G Vignati.

62 records · Page 4Linked to original sources

Dehydroepiandrosterone sulfate decreases the interleukin-2-mediated overactivity of the natural killer cell compartment in senile dementia of the Alzheimer type.

Since dehydroepiandrosterone sulfate (DHEAS) has been involved in the regulation of cellular immunity, the aim of the presence study was to evaluate whether the age-dependent reduction of DHEAS was associated with changes of natural killer (NK) immune function in healthy elderly subjects and in patients with senile dementia of the Alzheimer type (SDAT). Circulating DHEAS was determined throughout 24 h (circadian profile). NK cytotoxic activity was measured as spontaneous and induced cytotoxicity during exposure with DHEAS (10(-7) M), interleukin-2 (IL-2; 100 IU) and IL-2 (100 IU) coincubated with DHEAS (10(-7) M). DHEAS was significantly reduced in healthy elderly subjects (mesor M +/- SD = 2.3 +/- 0.5 micromol/l) and SDAT (1.6 +/- 0.4 micromol/l) patients compared to healthy young subjects (6.7 +/- 0.9 micromol/l; p < 0.001); significant differences were also found when healthy elderly subjects and SDAT patients were compared (p < 0.01). A significant inverse correlation between age and DHEAS levels was demonstrated in SDAT and healthy elderly subjects (p < 0.05). The decrease in 24-hour DHEAS secretion was associated with a higher NK cytotoxic response to DHEAS in the healthy elderly subject group than in healthy subjects of young age (p < 0.01). Increased NK cell activity during IL-2 incubation was found in patients with SDAT in comparison with the healthy elderly subject (p < 0.001). On the contrary, NK cell cytotoxic response of SDAT patients was less pronounced during DHEAS exposure and when DHEAS was coincubated with IL-2 (p < 0.001). These data suggest an immunomodulatory role of DHEAS on NK functional activity in physiological aging and SDAT. The antagonizing effect of DHEAS on NK overactivity during exposure with cytokines might counteract some neuroimmune components related to the pathogenesis and progression of the disease.

Adult↗

Evaluation of critical differences of CEA and CA 15.3 levels in serial samples from patients operated for breast cancer.

In the present investigation we evaluated the variability of tumor marker levels in the follow-up of patients without evidence of disease after resection of primary breast cancer. CEA and CA15.3 were measured using commercially available methods in serial blood samples collected from 170 patients. The coefficient of variation among all samples from each patient, which accounts for the total variability (analytical variability+biological variability), was widely scattered (from 4 to 99% for CEA; from 4 to 52% for CA15.3). The critical difference was calculated using the formula designed by Fraser [CD = 2.77. (CVa2 + CVb2)1/2]. It ranged from 11 to 276 for CEA and from 11 to 144 for CA15.3. From the present findings we conclude that: 1) it is possible to identify individually tailored decision criteria to evaluate tumor marker variations in the follow-up of breast cancer patients; 2) in a considerable number of cases the non-tumor-related variability is too high to allow the early identification of minor tumor marker variations that are of clinical relevance.

Analysis of Variance↗

[Surgical treatment of ulcerative rectocolitis: technical aspects of total restorative proctocolitis with S pouch].

Restorative proctocolectomy with an ileal-pouch-anal anastomosis seems to be the treatment of choice for ulcerative colitis. The aim of this study was to discuss a number of technical and functional aspects of the procedure that still appear to be controversial such as the shape of the pouch, the mucosectomy and the type of anastomosis. The authors report on their experience with the surgical treatment of ulcerative colitis with an "S" pouch. The technique reported, however, differs from the original method proposed by Parks and Nicholls in 1978 and the reasons for this surgical choice are discussed. A six-year experience (1993-1999) regarding 35 patients undergoing this approach is reported. No perioperative deaths were observed. The early and long-term complication rates were 8.5% and 11.4%, respectively. The average number of daily evacuations was 4. Mucosectomy affords complete resolution of the disease, while the particular shape of the pouch guarantees good functional results.

Adolescent↗

Tumor markers in breast cancer monitoring should be scheduled according to initial stage and follow-up time: a prospective study on 859 patients.

PURPOSE: The purpose of this study was to identify and standardize optimal decision criteria for maximizing the effectiveness of tumor markers in clinical use during the follow-up of patients operated on for breast cancer. MATERIALS AND METHODS: The study was prospectively performed on 859 patients enrolled in 10 institutions. A total of 13,337 determinations of CEA and 14,330 determinations of CA15.3 were available. The median number of samples per patient was 16 for CEA and 17 for CA15.3. The median follow-up was 7 years. Receiver-operating characteristic analysis was used to evaluate the ability of CEA and CA15.3 to discriminate relapses from patients who had no evidence of disease. The diagnostic performances of the two markers were evaluated using decision criteria based on both dichotomic cut-off points and dynamic variations among serial samples. RESULTS: We selected decision levels corresponding to preset levels of 90% and 99% specificity. Patients with CEA and/or CA15.3 levels above the cut-off values were considered positive only if a 1.5-fold increase occurred among the last sample and the mean of the first three samples. According to the different cut-offs used, specificity ranged from 94% to 99% and sensitivity from 48% to 63%. We calculated predictive values using the prevalence expected with reference to the stage of primary tumor and the length of follow-up. Positive predictive values ranged from 1.6% to 93.7%, and negative predictive values from 88.9% to 100%, according to the clinical scenarios and the decision criteria used. The choice of the decision criteria significantly affected positive predictive values within each patient subset. Differences related to time from surgery were still remarkable for every decision criteria (i.e., positive predictive values ranged from 36.6% to 2.8% in node-negative patients according to the year of observation, although the same cut-off point was used). DISCUSSION: The results of the present prospective study show that different decision criteria may provide different diagnostic performances for the same tumor marker and in the same patient. Therefore, we suggest that different decision criteria be settled and used according to the clinical goals.

Biomarkers, Tumor↗

[Immediate and late arrhythmia in patients operated on for tetralogy of Fallot].

UNLABELLED: Arrhythmias are a frequent complication after repair of tetralogy of Fallot (TOF). We present our experience with 97 patients with special consideration for early and late hyperkynetic arrhythmias. The most frequent, 4% of the patients, was in junctional tachycardia. Late arrhythmias can be atrial or ventricular. The incidence of ventricular arrhythmias in the literature range from 42 to 82%. In the Authors experience multiforme ventricular ectopy was present in 80% of the patients, 20 years after surgery. We suggest an exercise test and averaging ECG in all the patients. Thirty six percent of patients with supraventricular tachycardia were symptomatic. CONCLUSION: as the incidence of arrhythmias after correction of TOF is high, it is very important to periodically reassess these patients. Antiarrhythmic treatment is indicated in all symptomatic patients, especially in those with major arrhythmias (SVT, AF and VT).

Arrhythmias, Cardiac↗