Biomedical subjects
Publications and source records attributed to T Lettini.
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A morphometrical analytical evaluator of asymmetries of biological structures bonded by a closed curve was suggested. A second degree equation couple was found in order to detect, respectively according X and Y axis, first main asymmetry whereas third degree equation revealed first and second asymmetry for both abscissa and ordinate values. Final evaluator, named S.A.E. (Shape Analytical Evaluator), was computed as arch/cord ratio between function curve and its cord, it was equal to 1 for circles and any ellipse and symmetrical shapes whereas it was of different value for asymmetrical shapes.
An analytical morphometrical investigation of fronto facial profile of Plesianthropus transvaalensis was carried out by means of Fourier spectral series. Amplitude of contributors was evaluated in comparison with harmonic sets of a modern skull and two "mosaics" obtained by a convenient merging of segments of modern and hominid skull profiles. Patterns are distinctly different in Plesianthropus and modern profile because amplitude of second harmonic is greater than first in the former and viceversa in the latter; moreover while in Plesianthropus first and second harmonic give the same phase, it does not occur for modern skull. Fourier series of "mosaic" obtained by frontal profile of Plesianthropus and facial profile of modern resembles the set of modern skull while "mosaic" of modern frontal profile and hominid facial one resembles closely pattern of Plesianthropus.
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Histological grading of oral squamous cell carcinoma (OSCC) is usually evaluated in a semiquantitative way and this causes a low grade of reproducibility of this prognostic evaluation. The aim in this preliminary phase is to investigate the relation between nuclear shape (studied by an analytical procedure) and histological grading to evaluate the weight of nuclear shape and dimension in grading formulation. Nine cases of OSCC were studied (3 cases of G1, G2 and G3 respectively) with 20 nuclei for each case. All the tumors were localized on the lip. Histologic grading according to the Bryne system was performed. Each nucleus was submitted to a morphometrical study by the SAM (Shape Analytical Morphometry) system which, apart from dimensions allows us to evaluate nuclear contour irregularities and nuclear shape asymmetry. Nuclei of squamous cell carcinoma show a progressive increase in dimensions (area, perimeter and diameter) from G1 to G3. Nuclei of G3 carcinoma are characterized by the most irregular shape. Size differences (mean value) are significant to differentiate G1 nuclei from G2 and G3 nuclei while shape parameters are useful in distinguishing G3 nuclei from G1 and G2. Multivariate discriminant analysis showed that by using only nuclear parameters it is possible to correctly classify about 80% of nuclei. This study, using quantitative methods, confirmed nuclear pleomorphism to be the most important feature in grading evaluation.
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Meningiomas are the most common neoplasms of the central nervous system and their biological behavior is not always predictable from the histologic appearance of the tumors. The nuclear pleomorphism seems to be one of the most important morphological features in the prediction of recurrence. By using analytical morphometric methods it is possible to quantify nuclear atypias and to obtain parameters describing nuclear contour irregularities and distortions of the figure. Moreover the amount of information obtained from analytical procedure allowed to discriminate, by multivariate discriminant analysis recurrent or no-recurrent meningiomas (5% of error).