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Biomedical subjects

E Zannoni

Publications and source records attributed to E Zannoni.

8 recordsLinked to original sources
PubMed1997

Cytogenetic abnormalities and microsatellite instability in endometrial adenocarcinoma.

Recently various authors described a new mechanism involved in the genesis of some tumors, which is characterized by a tendency for replication mistakes and by genomic instability of microsatellite repeats. This instability can be revealed through the shift in the electrophoretic mobility of the analyzed fragments, which is due to a different number of repeat units. This phenomenon is widely documented in colorectal tumors of patients affected by hereditary nonpolyposis colorectal carcinoma (HNPCC). We performed a cytogenetic and molecular study of 23 endometrial adenocarcinomas to investigate the presence of genomic instability and to evaluate the possibility of a positive correlation with specific chromosomal changes. The study of genomic instability was performed using 23 microsatellites localized over 8 chromosomes. Genomic instability of microsatellites was observed in 3 cases over all 8 analyzed chromosomes. The tumoral stage of cases with microsatellite instability does not differ significantly from the remaining tumors. As a matter of fact several cases showing no evidence of instability were more advanced (II B, III A) than tumors with instability. In ten cases we observed trisomy of chromosome 10, in some as a sole anomaly. The 3 cases with genomic instability revealed a near-diploid karyotype and all showed the presence of a supernumerary marker derived from chromosome 1 rearrangements. A derivative chromosome 1 was revealed in 4 cases without evidence of microsatellite instability. It should be noted that the presence of many unidentified markers and the small number of tumors with instability do not allow us to give a definitive significance to this observation. Our results indicate that there is not an apparent correlation between microsatellite instability and specific chromosomal abnormalities. Moreover, we did not find any correlation between pathological characteristics of the tumor and genomic instability. Microsatellite instability appears to be a relatively rare event in endometrial carcinoma.

Adenocarcinoma↗
PubMed1997

Learning to control the program evolution process with cultural algorithms

Traditional software engineering dictates the use of modular and structured programming and top-down stepwise refinement techniques that reduce the amount of variability arising in the development process by establishing standard procedures to be followed while writing software. This focusing leads to reduced variability in the resulting products, due to the use of standardized constructs. Genetic programming (GP) performs heuristic search in the space of programs. Programs produced through the GP paradigm emerge as the result of simulated evolution and are built through a bottom-up process, incrementally augmenting their functionality until a satisfactory level of performance is reached. Can we automatically extract knowledge from the GP programming process that can be useful to focus the search and reduce product variability, thus leading to a more effective use of the available resources? An answer to this question is investigated with the aid of cultural algorithms. A new system, cultural algorithms with genetic programming (CAGP), is presented. The system has two levels. The first is the pool of genetic programs (population level), and the second is a knowledge repository (belief set) that is built during the GP run and is used to guide the search process. The microevolution within the population brings about potentially meaningful characteristics of the programs for the achievement of the given task, such as properties exhibited by the best performers in the population. CAGP extracts these features and represents them as the set of the current beliefs. Beliefs correspond to constraints that all the genetic operators and programs must follow. Interaction between the two levels occurs in one direction through the extraction process and, in the other, through the modulation of an individual's program parameters according to which, and how many, of the constraints it follows. CAGP is applied to solve an instance of the symbolic regression problem, in which a function of one variable needs to be discovered. The results of the experiments show an overall improvement on the average performance of CAGP over GP alone and a significant reduction of the complexity of the produced solution. Moreover, the execution time required by CAGP is comparable with the time required by GP alone.

Journal Article↗
PubMed1996

Sonographic endometrial thickness: a useful test to predict atrophy in patients with postmenopausal bleeding. An Italian multicenter study.

Eighteen centers took part in this prospective study into which 930 eligible patients were recruited. The selection criteria for admission were atypical bleeding after at least 6 months of postmenopausal amenorrhea, and absence of hormonal therapies for at least 6 months. The sonographic measurement of the maximum bi-endometrial thickness was made in a longitudinal plane. Sonographic measurements were always performed within 3 days prior to histological evaluation. In these patients the mean number of years from menopause (25-75th centile) was 6 (range 2-16). The prevalence of endometrial carcinoma was 11.5% and the prevalence of atrophy was 49.2%. The area under the receiver operator characteristic curves generated by sonographic thickness measurements reached the level of 85%, both for cancer and atrophy. The likelihood ratio for cancer, yielded by an endometrial thickness of < or = 4.0 mm, was 0.05, and for atrophy it was 7.1. This cut-off of > 4.0 mm yielded a sensitivity for the detection of cancer of 98% and a negative predictive value of 99%. The overall sensitivity and positive predictive value for atrophy achieved by this cut-off were 57.2% and 87.3%, respectively. A multivariate logistic model showed that age and body mass index were independent variables associated with a significantly higher risk of endometrial cancer. The post-test probabilities for cancer and atrophy were recalculated on the basis of the integration of age, body mass index and endometrial thickness. The estimated reduction of invasive procedures on the basis of this integration was 31%. Transvaginal sonographic measurement of endometrial thickness, integrated with individual risk factors, can help in the management of postmenopausal patients with atypical bleeding, with regard to either the need for histological evaluation in high risk cases, or the choice of possible expectant management. We have shown that an endometrial thickness of < or = 4.0 mm safely predicts endometrial atrophy and justifies expectant management when the patient understands the need for proper follow up. This could be achieved with a reduction in the use of invasive procedures without unwanted delay in cancer diagnosis.

Aged↗
PubMed1993

Endocervical detection of CIN. Cytobrush versus cotton.

Correct methods of sampling are essential for obtaining adequate smears for cytological diagnosis of cervicovaginal abnormalities. In this paper we report on 3 methods of sampling, Ayre spatula, cotton swab and cytobrush on 89 patients who underwent repeat smear and colposcopic examinations because of abnormal screening smears. The cytobrush device was better than Ayre spatula or cotton in collecting both endocervical and neoplastic cells. However, the combination of spatula and cotton was almost the same as spatula and cytobrush in recovering neoplastic cells. Therefore the rate of cervical intraepithelial neoplasia (CIN) diagnosis is more influenced by an adequate sampling of the endocervix than by the type of endocervical device.

Adult↗
PubMed1989

Comparison of repeat smear, colposcopy, and colposcopically directed biopsy in the evaluation of the mildly abnormal smear.

Repeat smear, colposcopy, and colposcopically directed biopsy were performed in 161 patients referred to our department because of a Pap smear showing mild dysplasia (CIN 1). Colposcopically directed biopsies revealed the presence of CIN of different grades in 61 cases (37.5%). In 33 (20.4%) the CIN grade found at biopsy was higher than 1. Repeat smear confirmed the presence of CIN 1 in 67 women (47.2%). In this group of patients colposcopically directed biopsies showed a CIN grade greater than 1 in 12 cases (17.9%). The repeat smear was negative in 59 patients (41.5%). In this group, biopsy showed varying grades of neoplasia in 12 cases. Colposcopic examination indicated no dysplasia but the presence of minor cervical abnormalities in 76 women (47.2%): at biopsy a CIN grade higher than 1 was found in 9 cases (11.5%). These data suggest that the mildly atypical smear identifies a group of patients at increased risk of CIN but gives little or no information on the disease severity. Repeat smear and colposcopic examination alone appear inadequate to demonstrate the severity of the cervical lesion. Due to the high proportion of CIN 2 and 3 in patients with a mildly abnormal smear, the systematic biopsy of any colposcopically abnormal area seems essential to proper management of the patient.

Adult↗
PubMedDate not supplied

[The diathermy loop and diathermic coagulation in the ambulatory treatment of intraepithelial cervical neoplasia].

Ninety-four patients suffering from CIN, of which 28 CIN1, 37 CIN2 and 29 CIN3 were treated with Cartier diathermal loop (57 cases 60.6%) or DTC (37 cases 29.4%). GSC proved visible in all cases except for a group of 16 patients in whom the combined use of ethinylestradiol and microendocervicoscopy showed GSC localisation within 5 mm of the OUE. The latter cases were all treated with Cartier diathermal loop. Results two months after the intervention showed correction of the colposcopic and cytological examination in 85 cases (94.4%) and bioptic cure in 91 cases (96.8%). In two cases, histological examination showed CIN1 and in one case CIN2.

Carcinoma in Situ↗