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Biomedical subjects

S Sisti

Publications and source records attributed to S Sisti.

28 records · Page 2Linked to original sources
PubMed1989

Reproducibility of DNA measurements in imprints of thyroid adenoma. Variation sources.

DNA measurement represents a type of quantitative analysis which allows us to gain prognostic information on malignant tumors and to study the natural history of the epithelial neoplasia. However, there are sources of variation in evaluating the DNA content. These include variation due to field selection, variation between observers (interobserver variation), and variation between laboratories (interlaboratory variation). The influence of various variation sources was studied in 4 experiments. When DNA measurements were made from the same microscopic fields, the results did not differ remarkably. However, observer training proved to be important. Intra- and interobserver variation was lower among experienced morphometrists than among inexpert observers. Different laboratories and image analyzers may give different results when the same case is measured. To overcome at least part of the potential variation sources, undergraduates and postgraduates at the Departments of Pathology of Ancona and Kuopio Universities are specially trained in the use and application of morphometry. Special sampling rules should be applied and observers encouraged to follow the rules as uniformly as possible.

Adenoma↗
PubMed1988

Reproducibility of mitotic counts and identification of mitotic figures in malignant glial tumors.

Quantitative pathology is a rapidly growing field of pathology. This field is developing methods allowing greater objectivity and better reproducibility in diagnostic decisions. The introduction of quantitative pathology as a teaching subject in medical education will help this field to become more widely and more correctly applied. Courses on quantitative pathology are organized yearly by the Department of Pathology at the University of Ancona. The 1986 course emphasized training of students in understanding basic problems such as variation caused by tissue processing, instrumentation, data handling and interpretation, and variation between observers. In this paper we describe experiments performed during the course on identification and quantitation of mitoses in malignant glial tumors. The participants, i.e. students of the postgraduate Pathology School, could identify mitoses with a 'substantial' reproducibility. However, when the observers were allowed freely to choose the fields to count, the reproducibility was 'slight'. The study suggests that sampling rules should be applied which secure reproducible application of morphometric method also on condition of free selection of fields. Because the application of such rules needs expertise in histopathology, it seems that morphometric method can best be applied by histopathologists themselves.

Glioma↗
PubMed1988

Prednisone-induced bone loss in sarcoidosis: a risk especially frequent in postmenopausal women.

The incidence of glucocorticoid-induced osteoporosis is reported in about 40 to 50% of treated patients, but it has never been extensively studied in sarcoidosis. We have studied Vertebral Cancellous Mineral Content (VCMC) of the lumbar spine by Quantitative Computed Tomography (QCT) in 190 normal subjects, 7 patients with sarcoid on no treatment and 64 patients with sarcoid on treatment with prednisone. As compared to the 190 normal subjects and the 7 untreated patients, VCMC was reduced in 46 of 64 patients with sarcoid on treatment with prednisone. Loss of VCMC in the patients varied directly with dose and duration of prednisone treatment. It is concluded that - in sarcoid patients and especially in postmenopausal females - long-term prednisone therapy results in bone mineral loss more frequently than elsewhere reported for other groups of patients. It is not clear if this difference is due to the sarcoidosis itself or to the better sensitivity of Computed Tomography compared to former techniques.

Adult↗
PubMed1988

Bone protection with salmon calcitonin (sCT) in the long-term steroid therapy of chronic sarcoidosis.

Prednisone-induced osteoporosis is very frequent in the long-term treatment of sarcoidosis (sarcoidosis 4:45-48, 1987). The aim of this work is to evaluate if salmon Calcitonin (sCT) is able to prevent osteopenia in the long-term. We have studied 53 patients with chronic histologically-proven sarcoidosis, all needing steroids, in a follow-up of 15 months; 20 of them were protected with sCT (100 I.U. i.m. daily for one month, then every two days for all the time of the study), 33 were unprotected. The two groups were matched for age, sex and total dose of prednisone. In order to overcome the differences of Vertebral Cancellous Mineral Content (VCMC) due to age and sex, we express VCMC in terms of Z score, i.e. the number of standard deviations above or below our normal means: initial Z score was -1.77 +/- 0.16 in the sCT group and -0.99 +/- 0.17 in the other group (P less than .05). For each subject we calculated the Mineral Loss (ML) in % of the initial value. At the end of the study ML% averaged -2.15(+/- 2.27) in the sCT protected group, and -14.11(+/- 2.08) in the unprotected group (P less than .001). We have also analysed the results limited to pts with initial Z score under -1 (19 sCT protected pts vs 18 unprotected). In these subgroups the ML% after 15 months averaged -13.62(+/- 2.9) in the unprotected group and -2.80(+/- 2.29) in the protected one (P less than .01). Finally we have studied another subgroup, i.e. 21 postmenopausal females: 9 were sCT protected, 12 were unprotected.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Prognostic value of computerized DNA analysis in noninvasive papillary carcinomas of the urinary bladder.

DNA parameters and a DNA status index were calculated in cases of noninvasive urothelial papillary carcinomas and apparently normal urothelium. DNA feature analysis included the measurement of basic parameters as well as those related to DNA deviation. Normal urothelium had a diploid content with a few values between 2c and 4c. The papillary lesions in the three grades showed a progressive decrease in diploid nuclei and steadily increasing percentages of tetraploid ones. One case of grade 1 papillary carcinoma and some of grade 2 showed a small proportion of aneuploid cells; the proportion quintupled in grade 3. The values of parameters related to DNA deviation increased progressively in the three grades, numerically expressing the shift from diploidy. The DNA status index is a multiparameter classification in which a single number, ranging from 0.5 to 3.7, expresses the degree of DNA deviation from a non-proliferating diploid population. The cases of normal urothelium and of grade 1 had the lowest values, from 0.5 to 1.9, whereas grade 3 cases had the highest, from 2.2 to 3.7. The index values of grade 2 cases were partly intermediate and partly in the range of the neighboring grades. The DNA status index has a prognostic significance. In fact, associated lesions and recurrences were only observed in cases with index values over 2.0.

Carcinoma, Papillary↗
PubMed1987

Researching osteoporosis in prednisone treated sarcoid patients.

Eighty-four normal subjects, 5 untreated sarcoid patients and 32 sarcoid patients under chronic prednisone therapy were submitted to Quantitative Computed Tomography (QCT) for Vertebral Cancellous Mineral Content (VCMC) evaluation. In the five untreated and in the 84 normal subjects, VCMC (given in mg/cm3) fell in the normal range found elsewhere. 22 of the 32 treated patients had lower than normal values. Osteoporosis (expressed through cancellous mineral loss) increased significantly (P less than .01) with increasing dose x time of prednisone therapy. We conclude that the bone loss is far more frequent than suspected in prednisone treated patients with sarcoidosis; yearly QCT could be a good tool for monitoring patients under chronic therapy.

Bone and Bones↗
PubMedDate not supplied

Interactive image analysis in the rectal mucosa of rheumatoid arthritis.

Interactive measurements of 22 quantitative parameters concerning the status and inflammation of the mucosa were taken in the rectal biopsies of patients suffering from Rheumatoid Arthritis, or with mild nonspecific morphological abnormalities (M.N.M.A.) and inflammation of the lamina propria or with Infective Colitis. The results showed that mean and standard deviation values of the rheumatoid patients are generally intermediate between those of control cases and those of M.N.M.A. and Infective Colitis. The variance analysis revealed that significant differences in some of the features exist between the four groups. Stepwise discriminant analysis helped in identifying three parameters that contributed significantly to discriminating 96.30% of the cases: Mucin area/Mucosal area; Number of inflammatory cells in the lower half/Number of inflammatory cells in the upper half of the mucosal thickness; Number of Granulocytes/mm2 of the lamina propria. Of the 27 cases included in the study, only one belonging to the control group was allocated incorrectly by the computer to the Rheumatoid Arthritis category. High correlation coefficients were observed between some of the morphometric, serological and clinical data in the rheumatoid patients. The highest values were between Number of Mononuclear cells/mm2 of lamina propria and C-Reactive Protein (+0.920) as well as between Mucin area/Mucosal area and serum IgM level (-0.950).

Adult↗
PubMedDate not supplied

Multivariate quantitative histopathological assessment of prognostic factors in ductal infiltrating breast carcinoma.

The aim of this study was to evaluate the power of quantitative pathology in improving the accuracy of prognosis in ductal infiltrating breast carcinoma. Ninety tumours were studied, with a diameter < or = 2.5 cm; positive (metastatic) axillary lymph nodes were found in 48 of the 90 cases; no patient had systemic metastases. Surviving patients had a mean follow-up of 106 months (minimum 69 months). At the end of the study, 45 patients were alive, 45 deceased. The histopathologic study of tumour nuclei and nucleoli included: a) geometric features, i.e., the mean and standard deviation of nuclear area, perimeter, diameter and form factor, nucleolar area and nucleolar/nuclear ratio, measured with a Kontron-IBAS automatic image analyser; b) immunohistochemical features, i.e., the percentage of PCNA (Proliferating Cell Nuclear Antigen)-positive nuclei, the expression (positive or negative) of vimentin (as a marker of tumour dedifferentiation), and the nuclear protein p53. Statistically significant differences were found between surviving and decreased patients for most features; multivariate analysis gave 92.2% accuracy in predicting outcome. Among the classes defined with multivariate analysis, it was possible to distinguish subsets of patients with bad prognosis by studying the expression of vimentin and p53, although these markers were positive in a small number of cases: 5 out of 6 patients with vimentin positivity and 4 out of 8 with p53 positivity died within 24 months of the diagnosis.

Antigens, Neoplasm↗
PubMedDate not supplied

Direct demonstration of cytokeratin filaments by electron microscopy in K562 cell lines in liquid culture.

Our previous study suggested the presence of cytokeratins in the supernatant of human K562 erythroleukemic cell line. In this study we confirm, by using an electron microscopy technique, that K562 cells contain typical intermediate tonofilaments with the characteristics of cytokeratins. After variable intervals of liquid culture, K562 cells have been examined for their clonogenic ability by immunostaining and ultrastructural study. K562 cells showed variable amounts of medium-sized filaments (intermediate filaments) of 10 nm mean size, having the submicroscopic pattern consistent with tonofilaments, arranged as electron-dense curve-shaped bundles, in perinuclear position independently from the different growth phases. A pool of monoclonal antibodies against cytokeratins confirmed the presence of cytokeratins in immunostaining, while the cytofluorimetric analysis showed an unexpected positivity of the CD34 antigen, associated with the typical adhesion molecule VLA5. In conclusion, the immunostaining with monoclonal antibodies and the ultrastructural findings suggest the expression of epithelial features in human K562 leukemic cells.

Cell Culture Techniques↗