Contributions of Portuguese cattle breeds to genetic diversity using marker-estimated kinships.

The quantitative assessment of genetic diversity within and between populations is important for decision-making in genetic conservation plans. In our study, we applied the livestock core set method to define the contribution of 15 cattle breeds, 11 of which are Portuguese indigenous cattle breeds, to genetic diversity. In livestock core set theory genetic diversity is defined as the maximum genetic variance that can be obtained in a random-mating population that is bred from the populations present in that core set. Two methods to estimate marker-estimated kinships to obtain the contributions to the core set were used in this study: the weighted log-linear model (WLM) and the weighted log-linear mixed model (WLMM). The breeds that contributed most to diversity in the core set were Holstein-Friesian followed by the Portuguese Mertolenga and Cachena for both WLM and WLMM methods. The ranking of relative contributions of cattle breeds was maintained when we considered only the Portuguese cattle breeds. Furthermore, we were able to identify the marginal contributions and respective losses of diversity for each of the 11 Portuguese cattle breeds when we considered a subset of populations that are not threatened of being lost (the Safe set composed of the four exotic breeds present in this study). When WLM was used losses in genetic diversity ranged from 2.68 to 0.65% while the loss in founder genome equivalents ranged from 37.37 to 8.43% for Mertolenga and Brava de Lide breeds respectively. When WLMM was used losses in genetic diversity and founder genome equivalents were less extreme than for the WLM method, ranging from 1.27 to 0.69 and 26.8 to 12.99 respectively.

Wavelet-based image estimation: an empirical Bayes approach using Jeffrey's noninformative prior.

The sparseness and decorrelation properties of the discrete wavelet transform have been exploited to develop powerful denoising methods. However, most of these methods have free parameters which have to be adjusted or estimated. In this paper, we propose a wavelet-based denoising technique without any free parameters; it is, in this sense, a "universal" method. Our approach uses empirical Bayes estimation based on a Jeffreys' noninformative prior; it is a step toward objective Bayesian wavelet-based denoising. The result is a remarkably simple fixed nonlinear shrinkage/thresholding rule which performs better than other more computationally demanding methods.

Unsupervised contour representation and estimation using B-splines and a minimum description length criterion.

This paper describes a new approach to adaptive estimation of parametric deformable contours based on B-spline representations. The problem is formulated in a statistical framework with the likelihood function being derived from a region-based image model. The parameters of the image model, the contour parameters, and the B-spline parameterization order (i.e., the number of control points) are all considered unknown. The parameterization order is estimated via a minimum description length (MDL) type criterion. A deterministic iterative algorithm is developed to implement the derived contour estimation criterion, the result is an unsupervised parametric deformable contour: it adapts its degree of smoothness/complexity (number of control points) and it also estimates the observation (image) model parameters. The experiments reported in the paper, performed on synthetic and real (medical) images, confirm the adequate and good performance of the approach.

Hormonal receptors in mammary carcinoma: comparison between quantitative and qualitative methods.

Alternatives to the traditional hormone receptor dosages for prognostic evaluation and clinical approach to breast cancer have been proposed for immunohistochemical determinations. For correlation purposes, such procedures were compared in 37 patients presenting 5 to 15 years of survival. Considering 30 fm/mg as the positivity index, the disagreement between both methods reached 35.1% with estrogen and 48.5% with progesterone receptors. When the positiveness level was changed to 20 fm/mg, the discrepancies were reduced to 32% with ER and increased to 57% with PgR. This study leads us to not recommend the immunohistochemical method applied to paraffin sections as an alternative procedure to the dextran-charcoal dosage for prognosis and therapeutic management of mammary carcinoma.

Unsupervised image restoration and edge location using compound Gauss-Markov random fields and the MDL principle.

Discontinuity-preserving Bayesian image restoration typically involves two Markov random fields: one representing the image intensities/gray levels to be recovered and another one signaling discontinuities/edges to be preserved. The usual strategy is to perform joint maximum a posterori (MAP) estimation of the image and its edges, which requires the specification of priors for both fields. Instead of taking an edge prior, we interpret discontinuities (in fact their locations) as deterministic unknown parameters of the compound Gauss-Markov random field (CGMRF), which is assumed to model the intensities. This strategy should allow inferring the discontinuity locations directly from the image with no further assumptions. However, an additional problem emerges: the number of parameters (edges) is unknown. To deal with it, we invoke the minimum description length (MDL) principle; according to MDL, the best edge configuration is the one that allows the shortest description of the image and its edges. Taking the other model parameters (noise and CGMRF variances) also as unknown, we propose a new unsupervised discontinuity-preserving image restoration criterion. Implementation is carried out by a continuation-type iterative algorithm which provides estimates of the number of discontinuities, their locations, the noise variance, the original image variance, and the original image itself (restored image). Experimental results with real and synthetic images are reported.

Sister chromatid exchange (SCE) in cattle: a comparison between normal and rob (1;29)-carrying karyotypes.

Fifty-one phenotypically normal Maronesa cattle (28 males and 23 females) from North-Portugal were studied to ascertain the frequency of SCEs in normal karyotypes and in karyotypes carrying rob (1;29). In the 1852 examined cells, the mean value of SCEs was 7.1 +/- 3.6. In the 841 cells from 23 normal karyotype animals the mean value of SCEs was 6.6 +/- 3.6; in the 611 cells from 17 heterozygous carriers of rob (1;29) the mean value of SCEs was 7.1 +/- 3.3; in 400 cells from 11 homozygous carriers the mean value of SCEs was 8.1 +/- 3.8. All these differences were highly significant (P < 0.001). No statistical differences were found between the mean values of SCEs in male (7.0 +/- 3.7) and female (7.1 +/- 3.5) cells in the total sampling. However, in 280 cells from two pairs of heterosexual twins, we found that the mean value of SCEs in female cells (7.9 +/- 3.0) was significantly higher than that in male cells (5.7 +/- 3.1).

A nonsmoothing approach to the estimation of vessel contours in angiograms.

Accurate and fully automatic assessment of vessel (stenoses) dimensions in angiographic images has been sought as a diagnostic tool, in particular for coronary heart disease. Here, the authors propose a new technique to estimate vessel borders in angiographic images, a necessary first step of any automatic analysis system. Unlike in previous approaches, the obtained edge estimates are not artificially smoothed; this is extremely important since quantitative analysis is the goal. Another important feature of the proposed technique is that no constant background is assumed, this making it well suited for nonsubtracted angiograms. The key aspect of the authors' approach is that continuity/smoothness constraints are not used to modify the estimates directly derived from the image (which would introduce distortion) but rather to elect (without modifying) candidate estimates. Robustness against unknown background is provided by the use a morphological edge operator, instead of some linear operator (such as a matched filter) which has to assume known background and known vessel shape.

Sequential and parallel image restoration: neural network implementations.

Sequential and parallel image restoration algorithms and their implementations on neural networks are proposed. For images degraded by linear blur and contaminated by additive white Gaussian noise, maximum a posteriori (MAP) estimation and regularization theory lead to the same high dimension convex optimization problem. The commonly adopted strategy (in using neural networks for image restoration) is to map the objective function of the optimization problem into the energy of a predefined network, taking advantage of its energy minimization properties. Departing from this approach, we propose neural implementations of iterative minimization algorithms which are first proved to converge. The developed schemes are based on modified Hopfield (1985) networks of graded elements, with both sequential and parallel updating schedules. An algorithm supported on a fully standard Hopfield network (binary elements and zero autoconnections) is also considered. Robustness with respect to finite numerical precision is studied, and examples with real images are presented.

IIB osteosarcoma. Current management, local control, and survival statistics--São Paulo, Brazil.

Ninety-two patients with IIB osteosarcoma of the extremities were treated with intraarterial (IA) cisplatinum (CDDP) followed by surgery [amputation (61.6%) or resection with endoprosthesis (38.4%)]. Postoperative chemotherapy alternating adriamycin and CDDP was used. The total three-year survival was 62.1%, and the disease-free survival was 41.1%. The pathologic evaluation of the degree of tumor necrosis in response to the IA CDDP showed that in 53.2%, the necrosis was over 90%. The multivariate analysis of prognostic factors has shown that the highest survival was among females with tumors smaller than 15 cm. Patients with lesions equal to or larger than 15 cm were three times as likely to die of the disease. A second, more aggressive study is now underway, in which high dose methotrexate (HDMTX) is preoperatively combined with adriamycin and CDDP. Following operation, ifosfamide is added to the cases with a smaller degree of tumor necrosis, while the other group of patients will continue with HDMTX, in addition to CDDP and adriamycin (these last two drugs are used in both arms). Until now, complete remission has been achieved in 82% and 86%, respectively, with a follow-up examination varying from four to 26 months (average, 14 months). This is of extreme importance, because the majority of the authors' patients have tumors at initial evaluation larger than 10 cm in diameter.

Increased survival, limb preservation, and prognostic factors for osteosarcoma.

Preoperative intraarterial (IA) cisplatin (CDP) was administered to 92 patients with nonmetastatic osteosarcoma. The ages of the patients ranged from 4 to 28 years. Sixty-four patients (70%) received 2 or 3 preoperative courses and 28 (30%) received 4 or more. Sixty-two specimens were available for pathologic examination to assess the degree of tumor necrosis. More than 90% tumor destruction was observed in 16 of 42 patients (38%) who received 1 to 3 preoperative courses as opposed to 17 of 20 (85%) who received 4 or more courses. Patients who received 4 or more courses had a 2-fold probability of achieving more than 90% tumor necrosis, and 68% underwent conservative surgery. Of those who received 3 or less courses, 23% underwent conservative surgery. Postoperatively, patients were treated with intravenous (IV) CDP alternating with doxorubicin (ADR) (Adriamycin, Adria Laboratories, Columbus, OH). Pulmonary metastases developed in 36 patients, bone metastases in 2, and local recurrence in 6. Two patients died of cardiac failure without evidence of disease. Thus, 46 patients (50%) were continuously free of disease 18 to 78 months after diagnosis. Univariate and multivariate analyses showed that male sex, low grade preoperative chemotherapy-induced necrosis, and nonosteoblastic histologic condition were prognostic factors predictive of recurrence, while male sex and large tumor size were prognostic factors predictive of death. These results are comparable with those reported by other centers and are superior to our previous experiences that yielded survival rates of 5% to 10%. A substantial number of patients also had the opportunity to achieve tumor removal with conservative surgery.

Soft-tissue sarcomas of the head and neck in adults and children: experience at a single institution with a review of literature.

Ninety-four soft-tissue sarcomas of head and neck occurring among 10,700 malignancies, seen during the period 1953-1980 in the head-and-neck surgical department, were studied with reference to age, sex, ethnic origin, site, histological type and survival. The objective was to review our own experience with sarcomas in these sites seen in the Department of Pathology, A.C. Camargo Hospital. The predominant site was the head. Fibrosarcoma was the most frequent type in adults and rhabdomyosarcoma, located exclusively in the head, was the most frequent in children.

Differential histologic diagnosis of osteoid. A study on human osteosarcoma collagen by the histochemical picrosirius-polarization method.

Using only one histologic preparation and under the light microscope, the simple method described here permits a distinction between osteoid and other tissue components that can be mistaken for osteoid. Osteoid from both normal osteogenesis and osteosarcomas is disclosed by the picrosirius-polarization method as a three-dimensional network of randomly arranged, thin, short, weakly birefringent collagenous structures which shine against a dark background. These morphologic features can be used as a precise diagnostic criterion for the differential diagnosis between osteoid and other materials which resemble osteoid by other staining techniques. This precise characterization of osteoid is of great importance since the presence of osteoid is used as a criterion for the differential diagnosis of osteosarcomas. Not only does this method permit the precise characterization of osteoid but it is also useful for studying collagen distribution in osteosarcomas. In this regard the foregoing results agree with the immunofluorescence observations recorded in the literature.