Purpose To report the regression of vascularized vitreous seeding in advanced "late" retinoblastoma
Methods Case report 8 year old girl with bilateral disease. The affected eye was the left eye ...(group D ‐ABC classification‐ and group VB ‐Reese Classification‐) while the right eye presented two peripheral retinomas.
Results Complete remission of the massive vascularized vitreous seeding was achieved and multiple retinal tumors regressed following six cycles of systemic chemotherapy (three drugs‐carboplatin etoposide and vincristine) and four intravitreal injections with Melphalan (20 micrograms). Retinal tumors presented type I regression (calcified tumors) while massive vitreous seeding was replaced by spidernet fibrotic formations.
Conclusion This case highlights the successful combination of three‐drugs systemic chemotherapy with intravitreal melphalan in advanced "late" retinoblastoma presenting with vascularized vitreous seeding and multiple retinal tumors.
Background The aim of our study was to evaluate retrospectively in a large single institution setting all cases of lung resections for colorectal metastases from 1998 to 2008 and to assess ...clinicopathologic factors influencing outcome. Methods In all, 199 patients, 125 men and 74 women, with lung metastases of colorectal cancer, 120 colon and 79 rectum, underwent resection with curative intent; mean interval between primary surgery and lung metastasis was 35 months. Carcinoembryonic antigen preoperative value was abnormal in 52 patients; K-RAS wild-type was detected in 60 of 97 examined cases; 75 patients received preoperative or postoperative chemotherapy or both. A solitary lesion was described in 95 patients (47.7%), two or three metastases in 72 (36.2%), and more than three metastases in 26 (13.1%). Nodal status was reported in 130 patients (73%). One hundred twenty patients (60.3%) underwent wedge resection, 27 (13.6%) underwent segmentectomy, and 52 (26.1%) had lobectomy. An R0 resection was achieved in 178 cases (89.4%). Results Median overall survival was 4.2 years (95% confidence interval: 3.1 to 5.1) with a 5-year overall survival of 43% (95% confidence interval: 36% to 50%). An R1 resection (log rank p = 0.0001), thoracic nodal involvement (log rank p = 0.0002), and preoperative abnormal carcinoembryonic antigen value (log rank p < 0.001) were significantly associated with poor outcome in univariate analysis. In multivariate analysis, the same variables plus the number of lesions (single versus multiple, p = 0.04) were shown to affect outcome. Conclusions An R0 resection, preoperative carcinoembryonic antigen, nodal involvement, and number of lesions represent strong prognostic factors in patient with lung metastases of colorectal cancer. The role of systemic treatments and biomolecular tests deserve future prospective investigations.
This paper introduces a three-dimensional model for simulating dense-snow avalanches, based on the numerical method of cellular automata. This method allows one to study the complex behavior of the ...avalanche by dividing it into small elements, whose interaction is described by simple laws, obtaining a reduction of the computational power needed to perform a three-dimensional simulation. Similar models by several authors have been used to model rock avalanches, mud and lava flows, and debris avalanches. A peculiar aspect of avalanche dynamics, i.e., the mechanisms of erosion of the snowpack and deposition of material from the avalanche is taken into account in the model. The capability of the proposed approach has been illustrated by modeling three documented avalanches that occurred in Susa Valley (Western Italian Alps). Despite the qualitative observations used for calibration, the proposed method is able to reproduce the correct three-dimensional avalanche path, using a digital terrain model, and the order of magnitude of the avalanche deposit volume.
Celotno besedilo
Dostopno za:
DOBA, FGGLJ, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This paper presents an extensive experimental analysis of two TCP-friendly congestion controls recently proposed in the literature, placing a special emphasis on the wireless setting. This work is ...motivated in part by the consideration that, to our knowledge, the majority of the results in this area are validated by simulation analysis rather than by experimentation. Testing these algorithms in real environments can help to verify their actual effectiveness for possible employment over the Internet. To reach our goal, we have implemented one representative algorithm among the so-called window-based TCP-friendly congestion controls, namely, the general additive increase multiplicative decrease (GAIMD) strategy, and used the publicly available code for the most popular control of the rate-based family, i.e., the TCP-friendly rate control (TFRC). We have then evaluated their TCP-fairness and smoothness in a test-bed featuring Cisco WAN equipment, as well as in an IEEE 802.11g wireless local area network (WLAN). Based on our results, we first propose and justify the tuning of TFRC to avoid a weird behavior that in the wireless environment this control occasionally exhibited. We next show that the GAIMD strategy reveals non-negligible scalability and smoothness problems that limit its performance, mainly in the radio setting. We empirically demonstrate that its increase/decrease rules, based on a TCP-Reno analytical model, do not guarantee an adequate performance when GAIMD competes with TCP-Sack, a de facto standard for current TCP implementations.
A wide variety of applications, ranging from rough cutting of stone and concrete to ultra-precision machining of ceramics for electronic components, are commonly performed with the so-called ...super-abrasive tools. The working part of such tools is made of hard particles, typically diamonds or cubic boron nitride crystals, embedded in a resin or sintered metal matrix. The performance of the tool is influenced by many technological aspects, but basically depends on the abrasion property of the hard particles-matrix system.
In the present paper, a mechanical approach is followed in order to link the performance of a tool to some relevant design parameters, i.e. hard particle content and diameter. The model is based both on theoretical and experimental evidences.
An experimental technique is described for the tool characterization, based on a coupled optical and laser-scanner acquisition of the tool working-surface. Moreover, the tool design parameters are put into play through a stereological model. The numerical strategy of the presented model is justified by a preliminary study of the contact stress distribution over the contact area.
Different useful parameters (i.e. distribution of contact stresses, number of active particles, etc.) are obtained from the numerical simulation of abrasion, although the performance of the tool is primarily evaluated from the estimated removed volume.
Purpose Iridociliary tumors are usually uncommon in childhood. Our aim is to describe cases of juvenile xanthogranuloma, iris tuberculoma and medulloepithelioma in young patients and to differentiate ...them from other similar lesions
Methods Retrospective cases study. Four patients ( two girls and two boys) were referred at the Referral Center for Retinoblastoma of the University of Siena. They underwent all the ophthalmological examination including standard procedures, MRI of the orbits, CT, UBM, immunological and molecular analysis. In three cases organ‐preserving operations were performed.
Results Two tumors were histologically identified as medulloepitheliomae. Two tumor‐like lesions were determined as juvenile xanthogranuloma and iris tuberculous granuloma. In the last case, antituberculous therapy was performed
Conclusion Iridociliary tumors and pseudotumors are rather rare in childhood. Nevertheless, they should be taken in consideration in differential diagnosis with other pediatric intraocular tumors, particularly retinoblastoma, ciliary body adenoma and adenocarcinoma. An executive checkup including pathology, immunohistochemistry and immunology is to be performed.
Purpose To report five years of conservative treatment for advanced retinoblastoma with the direct intra‐arterial‐ophthalmic artery infusion of Melphalan alone or Melphalan and Topotecan.
Methods 75 ...children (82 eyes) with advanced retinoblastoma (Stage D‐E/VA –VB) were entered in phase two of one center open study‐approved protocol of ophthalmic artery infusion (Italian intra‐arterial protocol, approved by the Ethic Commettee – University Hospital of Siena). Seven cases have been treated bilaterally. 40 eyes were first diagnosis (naïve) and 42 were relapses following chemotherapy and focal therapy and/or radiotherapy.
Results Cannulation of the ophthalmic artery was performed by a femoral artery approach using microcatheters (magic 1.5) while the children were under general anesthesia and anticoagulated. Chemotherapy (Melphalan alone or Melphalan and Topotecan) was infused into the artery over a 30‐minute period (dose of 3‐7 mg of Melphalan and 0.3‐0.4 mg of Topotecan, according to the age and size of the globe). Local and systemic toxicity have been evaluated and documented.
Conclusion 75 children (82 eyes) with advanced retinoblastoma were eligible for the intra‐arterial Italian Protocol. The 65.8% of all treated eyes is in complete remission. Superselective chemotherapy delivered through the ophthalmic artery can avoid enucleation, primary radiation or abuse of systemic chemotherapy.
Purpose To study the ophtahlmoscopic evolution of a retinocytoma diagnosed in a 8 months old boy.
Methods The patient was referred at the Referral Center for Retinoblastoma of the University of ...Siena, with the suspect of unilateral retinoblastoma. The boy was diagnosed as having retinocytoma based on ophthalmoscopic appearance. Monthly ophthalmoscopic and ecographic evaluation were recommended. Detailed fundus drawings and fundus photographs and descriptions of the retinocytoma were collected. The little boy underwent also MRI, genetic testing and fluorangiography.
Results Throughout the months, we observed a tumor regression from avascular mass with fish‐flesh appearance and microscopic calcifications to a retinal transparent mass with calcifications, retinal cysts and surrounded by chorioretinal atrophy.
Conclusion Retinocytoma is a rare benign retinal tumor with characteristic clinical features. Usually diagnosed in parents of retinoblastoma children, “silent” retinocytoma diagnosis is more rare in babies. In our case, we observed a natural “regression” of a retinocytoma in a 8 months old boy kept under close RETCAM follow‐up for the risk of malignant transformation.
PDF
