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Biomedical subjects

E Zanon

Publications and source records attributed to E Zanon.

At least 19 recordsLinked to original sources

A completely automated CAD system for mass detection in a large mammographic database.

Mass localization plays a crucial role in computer-aided detection (CAD) systems for the classification of suspicious regions in mammograms. In this article we present a completely automated classification system for the detection of masses in digitized mammographic images. The tool system we discuss consists in three processing levels: (a) Image segmentation for the localization of regions of interest (ROIs). This step relies on an iterative dynamical threshold algorithm able to select iso-intensity closed contours around gray level maxima of the mammogram. (b) ROI characterization by means of textural features computed from the gray tone spatial dependence matrix (GTSDM), containing second-order spatial statistics information on the pixel gray level intensity. As the images under study were recorded in different centers and with different machine settings, eight GTSDM features were selected so as to be invariant under monotonic transformation. In this way, the images do not need to be normalized, as the adopted features depend on the texture only, rather than on the gray tone levels, too. (c) ROI classification by means of a neural network, with supervision provided by the radiologist's diagnosis. The CAD system was evaluated on a large database of 3369 mammographic images [2307 negative, 1062 pathological (or positive), containing at least one confirmed mass, as diagnosed by an expert radiologist]. To assess the performance of the system, receiver operating characteristic (ROC) and free-response ROC analysis were employed. The area under the ROC curve was found to be Az = 0.783 +/- 0.008 for the ROI-based classification. When evaluating the accuracy of the CAD against the radiologist-drawn boundaries, 4.23 false positives per image are found at 80% of mass sensitivity.

Algorithms↗

Myocardial infarction, other arterial thrombosis and invasive coronary procedures, in hemaophilia B: a critical evaluation of reported cases.

Myocardial infarction and other arterial thrombosis are commonly maintained to be rare in hemophilia patients. This, in general, seems true but the occurrence of a thrombotic event in hemophilia B is not exceptional. A thorough search of the literature has yielded 13 patients with myocardial infarction and 1 patient with a cerebrovascular accident. There were three fatalities. In five cases MI occurred after infusion of Prothrombin Complex Concentrates. In three additional patients the event occurred after infusion of plasma, Feiba or cryoprecipitate supernatant. Four patients had an antero-lateral infarction. Two had a non-Q infarction and one each showed a multiple or a posterior-inferior form. Several therapeutic coronary procedures (GABG and PTCA) were carried out in hemophilia B patients without undue complication providing adequate level of FIX were maintained. Heparin prophilaxis was used in all patients but one. The analysis of the literature indicates that (1) MI may occur in hemophilia B patients and (2) that invasive coronary artery therapeutic procedures may be carried out without complications.

Coronary Thrombosis↗

Pregnancy and oral contraceptives in factor V deficiency: a study of 22 patients (five homozygotes and 17 heterozygotes) and review of the literature.

Information on the effect of pregnancy or oral contraceptives (OC) in congenital factor V (FV) deficiency is scanty. The personal investigation of five homozygous and 17 female heterozygous showed that patients with severe deficiency bleed considerably at the time of delivery. However, bleeding can be controlled properly by administration of fresh frozen plasma with excellent foetal outcome. The safe level for adequate haemostasis seems around 25% of normal. On the contrary, heterozygote patients show no significant postpartum bleeding and therefore need no substitution therapy. Oral contraceptives were taken and well tolerated by four of our homozygous patients and appear to be beneficial because they cause a decrease in menometrorrhagies thereby improving the anaemia and decreasing transfusional needs. One patient took hormonal replacement therapy with no undue effects. No thrombosis was noted in the propositae during oral contraceptive therapy. The review of the literature has allowed the gathering of information on 20 additional pregnancies. The foetal outcome was satisfactory in every instance. Excessive bleeding was noted in 11 pregnancies. In seven of the remaining pregnancies, no undue bleeding was noted thanks to appropriate substitution therapy. In the remaining two pregnancies no bleeding was noted and no substitution therapy was given. No data are apparently available in the literature about the use of OCs in FV deficiency.

Adult↗

GPCALMA: a Grid-based tool for mammographic screening.

OBJECTIVES: The next generation of high energy physics (HEP) experiments requires a GRID approach to a distributed computing system: the key concept is the Virtual ORGANISATION (VO), a group of distributed users with a common goal and the will to share their resources. METHODS: A similar approach, applied to a group of hospitals that joined the GPCALMA project (Grid Platform for Computer Assisted Library for MAmmography), will allow common screening programs for early diagnosis of breast and, in the future, lung cancer. The application code makes use of neural networks for the image analysis and is useful in improving the radiologists' diagnostic performance. GRID services allow remote image analysis and interactive online diagnosis, with a potential for a relevant reduction of the delays presently associated with screening programs. RESULTS AND CONCLUSIONS: A prototype of the system, based on AliEn GRID Services [1], is already available, with a central server running common services [2] and several clients connecting to it. Mammograms can be acquired in any location; the related information required to select and access them at any time is stored in a common service called Data Catalogue, which can be queried by any client. Thanks to the PROOF facility [3], the result of a query can be used as input for analysis algorithms, which are executed on the nodes where the input images are stored,. The selected approach avoids data transfers for all the images with a negative diagnosis and allows an almost real time diagnosis for the set of images with high cancer probability.

Algorithms↗

Severe factor X deficiency in pregnancy: case report and review of the literature.

Isolate factor X deficiency is an extremely rare clotting factor disorder inherited in autosomal recessive fashion and pregnancy in a homozygous patient is frequently complicated by recurrent miscarriage, uterine bleeding and premature labour. Eleven pregnancies in seven patients affected by FX deficiency have been reported in the literature. Two additional pregnancies have been reported in a FX variant (FX Friuli). We present a new case of successful at term pregnancy in a homozygous patient.

Adult↗

Ultrasonographically-guided fine-needle aspiration of axillary lymph nodes: role in breast cancer management.

The knowledge of the status of axillary lymph nodes (LN) of patients with breast cancer is a fundamental prerequisite in the therapeutic decision. In the present work, we evaluated the impact of fine-needle aspiration cytology (FNAC) of ultrasonographically (US) selected axillary LN in the diagnosis of LN metastases and subsequently in the treatment of patients with breast cancer. Axillary US was performed in 298 patients with diagnosed breast cancer (267 invasive carcinomas and 31 ductal carcinoma in situ DCIS), and in 95 patients it was followed by FNAC of US suspicious LN. Smears were examined by routine cytological staining. Cases of uncertain diagnosis were stained in immunocytochemistry (ICC) with a combination of anticytokeratin and anti-HMFG2 antibodies. Eighty-five FNAC were informative (49 LN were positive for metastases, 36 were negative). In 49 of 267 patients with invasive breast carcinoma (18%), a preoperative diagnosis of metastatic LN in the axilla could be confirmed. These patients could proceed directly to axillary dissection. In addition, US-guided FNAC presurgically scored 49 out of 88 (55%) metastatic LN. Of all others, with nonsuspicious LN on US (203 cases including 31 DCIS), in which no FNAC examination was performed, 28 invasive carcinomas (16%) turned out to be LN positive on histological examination. Based on these data, US examination should be performed in all patients with breast cancer adding ICC-supported FNAC only on US-suspect LN. This presurgical protocol is reliable for screening patients with LN metastases that should proceed directly to axillary dissection or adjuvant chemotherapy, thus avoiding sentinel lymph node biopsy.

Axilla↗

Psychological aspects and coping in haemophilic patients: a case-control study.

Although enormous progress has been made in recent years in the field of haemophilia, some problems still await solution, such as the risk of sudden haemorrhage, the sequelae of haemophilic arthropathy and social activities. We, therefore, carried out a case-control study in which some psychological dimensions (social expectations, tendency to depression, state of anxiety and self-esteem) were evaluated in a group of 60 haemophiliacs. A control group was formed of 78 healthy subjects matched for age, socio-economic class and level of education. The methodology used was the administration of self-assessment questionnaires which investigate and provide a quantitative measure of psychological dimensions. The results can be subjected to statistical analysis. Three self-assessment questionnaires were used: (i) the Marlowe-Crowne scale, (ii) the Beck Inventory version modified by Cusinato and (iii) the S.T.A.I.-form. Our aim was to evaluate: (i) whether there are significant differences in the considered psychological aspects between haemophiliacs and healthy subjects; (ii) whether there is a significant correlation between the psychological dimensions considered in the haemophiliacs and in the healthy subjects. The results showed that the haemophiliacs have a good psychological adaptation to their disease with the exception of their greater tendency to have less self-esteem than do the healthy subjects. As far as concerns the second aim, we found than self-esteem correlated with all the psychological variables investigated. This information could indicate the enormous importance that the psychological variable 'self-esteem' plays in haemophiliacs with respect to whether or not they develop depressive disorders and/or anxiety states.

Adaptation, Psychological↗

Oral contraceptives and venous thromboembolism: which are the safest preparations available?

Oral contraceptive therapy is associated with a fourfold increased risk of venous thromboembolism as compared with age-matched non-users. The composition of oral contraceptives has varied considerably during the past two to three decades. The estrogen content (ethinylestradiol) has decreased and is now less than 0.03 mg/pill. This was done on the assumption that estrogen was the main culprit for thrombotic complications. Subsequently it was found that the progestins contained in the pill could also play a thrombogenic role. This was particularly maintained to be so for the third-generations progestins, namely gestodene or desogestrel. These gonane progestins have been widely used since the early 1990s, because they appeared to have a lesser androgenic effect. A careful and impartial evaluation of the literature seems to indicate that third-generation progestins are associated with a slight increase in thrombotic risk. However, the significance of this difference remains to be proven. In fact, a relative risk of only two in retrospective studies may have limited effect and disappear in prospectives studies. The role of associated risk factors, both congenital and acquired, has been often overlooked in most of the papers dealing with the subject. This may be important. Preparations containing third-generation progestins are probably associated with a slight increase in thrombosis risk. It is the responsibility of the physician to select the preparation most suited for a given patient. As a general rule it may be safe to start with a preparation containing second-generation progestins. However there is no need for "a pill scare" and it does not seem justified to have women already taking pills containing third-generation progestins to switch to other preparations. If a woman taking preparations containing third-generation progestins experience symptoms, it is probably safe to advise that patient not to take any oral contraceptive pill in the future, regardless of the type. The same is true for women who experience symptoms while taking second-generation progestins preparations.

Contraceptives, Oral↗

Long-term use of oral contraceptive therapy in women with the prothrombin 20210 G-A polymorphism without thrombotic complications: a study of 13 women (12 heterozygotes and 1 homozygote).

Thirteen female patients with the prothrombin 20210 G-A abnormality (twelve heterozygotes and one homozygote) were selected out of 551 patients admitted to our Department of Medicine or to our Outpatient Hemostasis Units between January 1999 and October 2000. The selection was based on the fact that all patients had taken or were still taking oral contraceptives (OC) for a period of 3 years or longer than 3 years. None of these patents as gathered from history, physical examination, private physician records and our records has shown any DVT during or immediately after OC intake. Physical and compression ultrasonography examinations at the time of study were all negative. The average length of oral contraceptives therapy (OCT) was 10 years (range 3-23). The average age of patients at the time of oral contraception was 30 years. The 13 women had also 17 pregnancies without any venous thrombosis. The observations casts several doubt about the prothrombotic effect of this polymorphism. Since DVT has been shown to occur occasionally even in normal women, it is likely that the same may occur in women with this polymorphism regardless of the existence or not of any pathogenetic relationship between the two phenomena. Occasional reports suggesting a link between this polymorphism and oral contraception-related venous thrombosis should be carefully evaluated in order to avoid premature and incorrect conclusions.

Adult↗

Early transfusion of factor VIII/von Willebrand factor concentrates seems to be effective in the treatment of gastrointestinal bleeding in patients with von Willebrand type III disease.

The association between gastrointestinal angiodysplasia and von Willebrand disease was reported 30 years ago. The clinical course of patients with von Willebrand disease and angiodysplasia is characterized by numerous admissions to hospital for gastrointestinal bleeding necessitating transfusion with packed red cells, factor VIII and plasma. The management of these patients is problematic. Numerous treatments for the gastrointestinal bleeding have been proposed: surgery, electrocoagulation, laser photocoagulation, sclerotherapy, arteriography with embolization, immunoglobulins, oestrogens, and octreotide, but no treatment modality has been successful in all cases. We report a 66-year-old-female with small bowel angiodysplasia and von Willebrand type III disease in whom prompt administration of factor VIII/vWF concentrates was effective. Education of patients to recognize minimal gastrointestinal bleeding manifestations, periodical clinical visits and early infusion of factor VIII/vWF seems to be fundamental for the success of this therapy. A longer follow-up and the study of other patients are needed to confirm our observation.

Aged↗

Mild bleeding diathesis in a boy with combined severe haemophilia B (C(10400)-->T) and heterozygous factor V Leiden.

Haemophilia B patients with factor IX (FIX) activity < 1% are usually characterized by severe bleeding episodes early in life. We report a case of sporadic severe haemophilia B, clinically characterized by mild bleeding diathesis. The presence of anamnestic thrombophlebitis in the patient's mother prompted us to investigate a possible associated hypercoagulable condition. Resistance to activated protein C due to factor V R506Q mutation was present in the mother and in the propositus, in the homozygous and heterozygous form, respectively. Molecular analysis of the FIX gene led to the identification of a nonsense mutation resulting in a stop codon at position 50, previously described and usually responsible for a severe pattern of haemophilia B. The implications of this unusual association are discussed.

Activated Protein C Resistance↗

Prevention of venous thromboembolism in high-risk surgical and medical patients.

Although pharmacologic prophylaxis against venous thromboembolism has become the standard of care following total hip and knee replacement, prophylaxis among patients undergoing surgery for hip fracture and other lower extremity trauma remains underutilized. Available experience consistently supports the view that low-molecular-weight heparins are more effective than unfractionated heparin for prevention of proximal deep vein thrombosis (DVT) with no additional hemorrhagic risk and more effective than oral anticoagulants for prevention of in-hospital (mostly distal) venous thrombosis at the price of a higher surgical site bleeding and wound hematoma. The choice between low-molecular-weight heparin and warfarin should be tailored to the individual patients based on the clinical assessment of postoperative thrombosis and bleeding risk as well as the prophylaxis-specific cost and convenience. Whether thromboprophylaxis should be continued for a few additional weeks after hospital discharge is controversial. The overall incidence of postoperative DVT in patients with cancer is about twice as high as that of patients free of malignancy. Accordingly, they require prophylactic measures comparable with those usually recommended for major orthopedic surgery. In this setting, dermatan sulfate shows promise. In contrast to surgical patients, prevention of venous thromboembolism is less well studied in hospitalized medical patients. In a recent controlled randomized trial, enoxaparin in high prophylactic doses was an effective and safe measure of thromboprophylaxis in ordinary bedridden patients.

Anesthesia, Conduction↗

Hemophilia A, von Willebrand disease, and atherosclerosis of abdominal aorta and leg arteries: factor VIII and von Willebrand factor defects appear to protect abdominal aorta and leg arteries from atherosclerosis.

We hypothesized that patients with hemophilia or von Willebrand disease might be protected from atherosclerosis because of their coagulation defect. We studied 40 subjects affected by these two coagulation diseases using echocolor Doppler of the abdominal aorta and leg arteries, and compared the results with those obtained in 40 control patients who were homogenous with study patients in terms of sex, age, and risk factors for atherosclerosis. The probands presented a lower number of plaques than the 40 control subjects in the aorta and in the leg arteries. The most serious hemophilic patients had fewer plaques than controls or than patients with mild hemophilia. Both hemophilia and von Willebrand disease seem to protect against atherosclerosis.

Aorta, Abdominal↗

Proposal of a standard approach to dental extraction in haemophilia patients. A case-control study with good results.

We found no case-control studies on dental extraction in haemophilia patients in the literature even though the use of antifibrinolytic agents following a single infusion of factor VIII or IX has been accompanied by a lower number of bleeding complications in dental extractions. In this study we verified the incidence of bleeding complications after dental extraction in a group of 77 haemophilia patients. One hundred and eighty-four male patients requiring dental extraction represented the control group. All haemophilia patients received 20 mg kg-1 of tranexamic acid and a single infusion of factor VIII or IX to achieve a peak level about 30% of factor VIII or IX in vivo prior to dental extraction. Forty-five of 98 (45.9%) dental extractions in haemophilia patients and 110 of 239 (46%) dental extractions in the control group were surgical ones. We registered two bleeding complications in the group of haemophilia patients (one late bleeding and one haematoma in the site of the anaesthetic injection) and one (a late bleeding) in the control group. The difference of bleeding complications in the two groups of patients were not statistically significant (P=0.2; OR 0.2; CI 0.01-2.22). The protocol proposed in this study, characterized by the feasibility and the number of haemorrhagic complications not different from normal population, make dental extractions in haemophilia patients possible on an out-patient basis with a cost reduction for the community and minor discomfort for the patients.

Adult↗

[Evaluation of the body posture of nursing personnel when moving patients in bed].

The patients' movement in bed, is a procedure that demand great physical effort and use of good corporal mechanics for the nursing personnel, relative of preventing them back pain problems. Recognizing the importance of the movement and positioning, to promote safety and comfort to the patient, and before the professionals' complaints, described in the literature, this work has for objectives: to identify and analyzer the postures assumed by the nursing workers and identify the means and difficulties found during the execution of the referred activity. Through the technique of direct observation they were filmed, through videotapes, thirty procedures of patient's movement in the bed executed by nursing workers of an orthopedic clinic of an university hospital. The results evidence that the thirty procedures were executed along 197.41 minutes and that the corporal postures more frequently assumed they were, in respect to back, arms and legs, back inclined/arms with elbow down of row of seats/legs extension (53.76%). In agreement with the beginnings of the corporal mechanics and of the ergonomics, such postures are considered painful to the man, due to the muscle-skeletal aggressions and to the physical overload that they cart. The workers aimed the aspects little space (58.82%), physical load (52.94%) and absence of the personal (47.06%), as the main difficulties found in the execution of patient's movement in the bed, corroborating with the discoveries of the literature, characterizing that activity as painful. They pointed: the adequate technique (36.29%), used of sheet (35.29%) and space adequate (23.52%), as aspects that would facilitate the execution of the procedure.

Back Pain↗