Singularités des surfaces paramétrées : courbures et isolignes uv serrées

Considering a CAD surface (resulting from a Computer-Aided Design system) defined by a planar domain parametrization, the first objective is to evaluate numerically the principal curvatures and directions at a given point of these surface and more particularly at the neighborhood of singular points (where partial derivatives are null or collinear). Secondly, the phenomenon of tight \textit{uv} isolines will be presented, which has for principal effect to transform a regular geometrical pattern in the parameters domain into a degenerated element in the Euclidian space, which is harmful for surface mesh generation.Etant donnée une surface CAO (issue de la Conception Assistée par Ordinateur) définie via une paramétrisation d'un domaine plan, le premier objectif est d'évaluer numériquement les courbures et les directions principales en un point quelconque de cette surface et plus particulièrement au voisinage des points singuliers (où les dérivées partielles sont nulles ou colinéaires). Dans un second temps, il s'agira de mettre en évidence le phénomène dit des isolignes uv serrées, qui a pour principal effet de transformer une forme géométrique régulière dans le domaine des paramètres en un élément dégénéré dans l'espace euclidien, ce qui est néfaste dans le cadre de la génération de maillages surfaciques

Singularités des surfaces paramétrées : courbures et isolignes uv serrées

Considering a CAD surface (resulting from a Computer-Aided Design system) defined by a planar domain parametrization, the first objective is to evaluate numerically the principal curvatures and directions at a given point of these surface and more particularly at the neighborhood of singular points (where partial derivatives are null or collinear). Secondly, the phenomenon of tight \textit{uv} isolines will be presented, which has for principal effect to transform a regular geometrical pattern in the parameters domain into a degenerated element in the Euclidian space, which is harmful for surface mesh generation.Etant donnée une surface CAO (issue de la Conception Assistée par Ordinateur) définie via une paramétrisation d'un domaine plan, le premier objectif est d'évaluer numériquement les courbures et les directions principales en un point quelconque de cette surface et plus particulièrement au voisinage des points singuliers (où les dérivées partielles sont nulles ou colinéaires). Dans un second temps, il s'agira de mettre en évidence le phénomène dit des isolignes uv serrées, qui a pour principal effet de transformer une forme géométrique régulière dans le domaine des paramètres en un élément dégénéré dans l'espace euclidien, ce qui est néfaste dans le cadre de la génération de maillages surfaciques

Prospective evaluation of prostate cancer detected on biopsies 1, 2, 3 and 4: When should we stop?

Purpose: We evaluated biochemical parameters and pathological features, as well as biopsy related morbidity of prostate cancer detected on biopsies 2, 3 and 4 in men with total serum prostate specific antigen (PSA) between 4 and 10 ng./ml. These features were compared to those detected on prostate biopsy 1. Materials and Methods: In this prospective European Prostate Cancer Detection study 1,051 men with total PSA between 4 and 10 ng./ml. underwent transrectal ultrasound guided sextant biopsy and 2 additional transition zone biopsies. All patients in whom biopsy samples were negative for prostate cancer underwent biopsy 2 after 6 weeks. If also negative, biopsies 3 and even 4 were performed at 8-week intervals. Those patients with clinically localized cancer underwent radical prostatectomy. Pathological and clinical features of patients diagnosed with cancer on either biopsy 1 or 2 and clinically organ confined disease who agreed to undergo radical prostatectomy were compared. Results: Cancer detection rates on biopsies 1, 2, 3 and 4 were 22% (231 of 1,051), 10% (83 of 820), 5% (36 of 737) and 4% (4 of 94), respectively. Overall, of the patients with clinically localized disease, which was 67% of cancers detected, 86% underwent radical prostatectomy and 14% opted for watchful waiting or radiation therapy. Overall, 58.0%, 60.9%, 86.3% and 100% of patients had organ confined disease on biopsies 1, 2, 3 and 4, respectively. Despite statistically significant differences in regard to multifocality (p=0.009) and cancer location (p=0.001), including cancer on biopsy 2 showing a lower rate of multifocality and a more apico-dorsal location, there were no differences in regard to stage (p=0.2), Gleason score (p=0.3), percent Gleason grade 4/5 (p=0.2), serum PSA and patient age between biopsies 1 and 2. However, cancer detected on biopsies 3 and 4 had a significantly lower Gleason score (p=0.001 and 0.001), lower rate of grade 4/5 (p=0.02), and lower volume (p=0.001 and 0.001) and stage (p=0.001), respectively. Conclusions: Despite differences in location and multifocality, pathological and biochemical features of cancer detected on biopsies 1 and 2 were similar, suggesting comparable biological behaviors. Cancer detected on biopsies 3 and 4 had a lower grade, stage and volume compared with that on biopsies i and 2. Morbidity on biopsies 1 and 2 was similar, whereas biopsies 3 and 4 had a slightly higher complication rate. Therefore, biopsy 2 in all cases of a negative finding on biopsy 1 appears justified. However, biopsies 3 and 4 should only be obtained in select patients with a high suspicion of cancer and/or poor prognostic factors on biopsy 1 or 2.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Pathological features of prostate cancer detected on initial and repeat prostate biopsy: Results of the prospective European prostate cancer detection study

PURPOSE. We evaluated pathological features of prostate cancer detected on repeat prostate biopsy in men with a serum total prostate-specific antigen (PSA) level between 4 and 10 ng/ml who were diagnosed with benign prostatic tissue after an initial biopsy and compared them to those cancers detected on initial prostate biopsy. MATERIAL AND METHODS. In this prospective European prostate cancer detection study, 1,051 men with a total PSA level between 4 and 10 ng/ml underwent transrectal ultrasound (TRUS)-guided sextant biopsy and two additional transition zone biopsies. All subjects whose biopsy samples were negative for prostate cancer (CAP) underwent a repeat biopsy after 6 weeks. Those with clinically localized cancers underwent radical prostatectomy. Pathological and clinical features of patients diagnosed with cancer on either initial or repeat biopsy and clinically organ confined disease who agreed to undergo radical prostatectomy were compared. RESULTS. Initial biopsy was positive (CAP) in 231 of 1,051 enrolled subjects and negative (benign histology) in 820 subjects. Of these 820 subjects, CaP was detected in 10% (83/820) upon repeat biopsy. Of cancers detected on initial and repeat biopsy, 148/231 (64%) and 56/83 (67.5%) had clinically localized disease, respectively, and were offered radical prostatectomy. 10/148 (6.7%) and 3/56 (5.3%), respectively, opted for radiation therapy and thus, 138/148 (93.3%) and 53/56 (94.7%), respectively, underwent radical retropubic prostatectomy. There were statistically significant differences with respect to multifocality (P = 0.009) and cancer location (P < 0.001) with cancers on repeat biopsy showing a lower rate of multifocality and a more apico-dorsal location. In contrast, there were no differences with respect to stage (P=0.2), Gleason score (P=0.36), percentage Gleason grade 4/5 (P=0.1), serum PSA (P = 0.62), and patient age (P = 0.517). CONCLUSIONS. At least 10% of patients with negative prostatic biopsy results will be diagnosed with CaP on repeat biopsy. Despite differences in location and multifocality, pathological and biochemical features of cancers detected on initial and repeat biopsy are similar, suggesting similar biological behavior and thus advocating for a repeat prostate biopsy in case of a negative finding on initial biopsy. Cancers missed on initial biopsy and subsequently detected on repeat biopsy are located in a more apico-dorsal location. Repeat biopsies should thus be directed to this rather spared area in order to improve cancer detection rates. © 2001 Wiley-Liss, Inc.SCOPUS: ar.jFLWINinfo:eu-repo/semantics/publishe

A nationwide study of acquired C1-inhibitor deficiency in France : Characteristics and treatment responses in 92 patients

International audienceAcquired angioedema (AAE) due to C1-inhibitor (C1INH) deficiency is rare. Treatment options for acute attacks are variable and used off-label. Successful treatment of the associated lymphoma with rituximab seems to prevent acute attacks in subjects with AAE. The aim of this study was to describe AAE manifestations, its associated diseases, and patients’ responses to treatments in a representative cohort.A retrospective nationwide study was conducted in France. The inclusion criteria were recurrent angioedema attacks and an acquired decrease in functional C1INH <50% of the reference value.A total of 92 cases were included, with a median age at onset of 62 years. Facial edema and abdominal pain were the most frequent symptoms. Fifteen patients were hospitalized in the intensive care unit because of laryngeal edema, and 1 patient died. Anti-C1INH antibodies were present in 43 patients. The associated diseases were primarily non-Hodgkin lymphoma (n = 44, with 24 splenic marginal zone lymphomas) and monoclonal gammopathy of undetermined significance (n = 24). Three patients had myeloma, 1 had amyloid light-chain (of immunoglobulin) (AL) amyloidosis, 1 patient had a bronchial adenocarcinoma, and 19 patients had no associated disease. Icatibant relieved the symptoms in all treated patients (n = 26), and plasma-derived C1INH concentrate in 19 of 21 treated patients. Six patients experienced thromboembolic events under tranexamic acid prophylaxis. Rituximab prevented angioedema in 27 of 34 patients as a monotherapy or in association with chemotherapy. Splenectomy controlled AAE in 7 patients treated for splenic marginal zone lymphoma. After a median follow-up of 4.2 years, angioedema was on remission in 52 patients.AAE cases are primarily associated with indolent lymphoma—especially splenic marginal zone lymphoma—and monoclonal gammopathy of undetermined significance but not with autoimmune diseases or other conditions. Icatibant and plasma-derived C1INH concentrate control attacks; splenectomy and immunochemotherapy prevent angioedema in lymphoma setting

Recommendations for Treating Males: An Ethical Rationale for the Inclusion of Testicular Self-Examination (TSE) in a Standard of Care

The phrase standard of care is primarily a legal term representing what procedure a reasonable person (i.e., health practitioner) would administer to patients across similar circumstances. One major concern for health practitioners is delivering and advocating for treatments not defined as a standard of care. While providing such treatments may meet certain ethical imperatives, doing so may unwittingly trigger medical malpractice litigation fears from practitioners. Apprehension to deviate, even slightly, from the standard of care may (seem to) put the practitioner at significant risk for litigation, which, in turn, may limit options for treatment and preventive measures recommended by the practitioner. Specific to testicular treatment, certain guidelines exist for cancer, torsion, vasectomy, and scrotal masses, among others. As it relates to screening, practitioner examination is expected for patients presenting with testicular abnormalities. Testicular self-examination (TSE) advocacy, however, is discouraged by the U.S. Preventive Services Task Force, which may prompt a general unwillingness among health practitioners to promote the behavior. Considering the benefits TSE has beyond cancer detection, and the historical support it has received among health practitioners, it is paramount to consider the ethical implications of its official exclusion from preventive health and clinical care recommendations (i.e., standard of care). Since good ethics should lead practitioner patient care guidelines, not fear of increased malpractice risks, we recommend the development of a standard of care for counseling males to perform TSE