An Efficient Procedure to Compensate for the Errors Due to the Probe Mispositioning in a Cylindrical Near-Field Facility.

This paper deals with the compensation of the probe mispositioning errors occurring in a cylindrical near-field (NF) facility due to the imprecise control of the linear and azimuthal positioners allowing the cylindrical scanning and/or to their limited resolution and to defects in the rails guiding the linear motion. As a result, 3-D errors in the positioning of the probe at any sampling point, as prescribed by the adopted non-redundant representation, affect the accuracy of the NF measurements. An efficient procedure is here proposed to properly compensate for these errors. It involves two steps. The former allows one to correct the mispositioning errors due to the deviation of each actual sampling point from the nominal measurement cylinder. The latter makes use of an iterative technique to restore the NF samples at any sampling point fixed by the used non-redundant representation from the ones obtained at the previous step and affected by 2-D mispositioning errors. Once these steps have been fruitfully applied, the so-compensated NF samples are effectively interpolated through a 2-D optimal sampling interpolation (OSI) formula to accurately reconstruct the input data required to perform the traditional cylindrical near-to-far-field transformation. The OSI representation is here developed by considering an elongated antenna under test as enclosed either in a prolate spheroid or in a cylinder terminated by two half spheres (rounded cylinder) in order to make the representation effectively non-redundant. Numerical test results, which thoroughly prove the efficacy of the devised procedure in correcting even severe 3-D mispositioning errors, are reported.

An Effective Near-Field to Far-Field Transformation with Planar Spiral Scanning for Flat Antennas under Test.

The goal of this article is to provide numerical and experimental assessments of an effective near-field to far-field transformation (NF-FF T) technique with planar spiral scanning for flat antennas under test (AUTs), which requires a non-redundant, i.e., minimum, number of NF measurements. This technique has its roots in the theory of non-redundant sampling representations of electromagnetic fields and was devised by suitably applying the unified theory of spiral scans for non-volumetric antennas to the case in which the considered AUT is modeled by a circular disk having its radius equal to half of the AUT's maximum dimension. It makes use of a 2D optimal sampling interpolation (OSI) formula to accurately determine the massive amount of NF data required by the classical plane-rectangular NF-FF T technique from the non-redundant data gathered along the spiral. It must be emphasized that, when considering flat AUTs, the developed transformation allows one to further and significantly save measurement time as compared to that required by the previously developed NF-FF T techniques with planar spiral scans based on a quasi-planar antenna modeling, because the number of turns of the spiral and that of NF data to be acquired depend somewhat on the area of the modeling surface. The reported numerical simulations assess the accuracy of the proposed NF-FF T technique, whereas the experimental tests prove its practical feasibility.

Role of gremlin-1 in the pathophysiology of the adipose tissues.

Gremlin-1 is a secreted bone morphogenetic protein (BMP) antagonist playing a pivotal role in the regulation of tissue formation and embryonic development. Since its first identification in 1997, gremlin-1 has been shown to be a multifunctional factor involved in wound healing, inflammation, cancer and tissue fibrosis. Among others, the activity of gremlin-1 is mediated by its interaction with BMPs or with membrane receptors such as the vascular endothelial growth factor receptor 2 (VEGFR2) or heparan sulfate proteoglycans (HSPGs). Growing evidence has highlighted a central role of gremlin-1 in the homeostasis of the adipose tissue (AT). Of note, gremlin-1 is involved in AT dysfunction during type 2 diabetes, obesity and non-alcoholic fatty liver disease (NAFLD) metabolic disorders. In this review we discuss recent findings on gremlin-1 involvement in AT biology, with particular attention to its role in metabolic diseases, to highlight its potential as a prognostic marker and therapeutic target.

Reconstruction of the Far-Field Pattern of Volumetric AUTs from a Reduced Set of Near-Field Samples Collected along a Planar Spiral with a Uniform Step.

An efficient near-to-far-field transformation (NTFFT) technique, wherein the near-field (NF) measurements are acquired along a planar spiral with a uniform step to make the control of the involved positioners easier, is developed in this article. Such a technique is tailored for quasi-spherical, i.e., volumetric, antennas under test and makes use of a reduced number of NF data. An effective two-dimensional sampling interpolation algorithm, allowing the accurate reconstruction of the input NF data for the standard NTFFT with plane-rectangular scan, is obtained by setting the spiral step equal to the sample spacing required for interpolating along a radial line according to the spatial bandlimitation properties of electromagnetic fields, and by properly developing a non-redundant representation along such a spiral. Tests results are reported to demonstrate that the proposed NTFFT technique retains the same accuracy as the standard plane-rectangular one.

Percutaneous lung biopsies: performance of an optical CT-based navigation system with a low-dose protocol.

OBJECTIVES: To compare patients' radiation exposure, technical feasibility, imaging quality and complication rate of percutaneous lung biopsies (PLBs) performed with a low-dose (LD) CT protocol under guidance of an optical navigation system. METHODS: Fifty-two consecutive patients with suspected malignant lung lesions were enrolled and randomised into group 1 (PLBs under the guidance of the navigation system) and group 2 (PLBs under the guidance navigation system with an LD protocol). Patients' demographics, lesion features, procedure-related variables and CT image quality for group 2 were recorded and compared. RESULTS: Technical success was 100 % in both groups. The radiation dose to patients' chest was significantly lower in group 2 than in group 1 (group 1: mean TDLP 206 ± 59 mGy·cm, ~ 3.5 ± 1.0 mSv; group 2: 54.2 ± 46.2 mGy·cm, ~ 0.92 ± 0.78 mSv; P < 0.0001). The PNX rate was 12 % in group 1 and 11.1 % in group 2. The haemoptysis rate was 8.0 % in group 1 and 3.7 % in group 2. CT image quality obtained in group 2 was always rated as adequate and as excellent in 15 cases (56.0 %). CONCLUSIONS: An optical navigation system with LD CT protocol is useful for performing lung biopsies with decreased patient radiation exposure. KEY POINTS: • Navigation systems are useful tools in percutaneous imaging-guided procedures. • For lung biopsies, low-dose (LD) CT protocols may be used. • Combining LD protocols with optical CT navigation results in significantly reduced radiation exposure.

Stature estimation from scapular measurements by CT scan evaluation in an Italian population.

This study evaluated the correlation between scapula size and stature and developed standard equations in order to estimate stature by CT scan evaluation. A total of 200 healthy Italian subjects (100 men and 100 women, mean age 64.2±12.8years) underwent thoracic CT scan evaluation during pulmonary screening in our department; we measured the stature of each patient with standard anthropometric instruments and then analyzed images to calculate the longitudinal scapular length (LSL) and the transverse scapular length (TSL). The correlation between stature and each parameter measured was analyzed by dividing the population into two groups, males and females, and was examined by simple regression analysis using Pearson's correlation coefficient (r). Each anthropometric variable showed a significant difference between males and females (p value <0.001). The correlation coefficients (r-values) were LSL=0.74 and TSL=0.51 in males and LSL=0.70 and TSL=0.48 in females. In both sexes the r-values showed a significant correlation between stature and LSL. Our study demonstrates that scapulae can be used for stature estimation; in our sample LSL was found to have a better correlation with stature then TSL. hm=4.247*LSL+93.74 and hf=4.031*LSL+92.38 are the formulae that provide the most accurate stature assessment in males and females respectively.

Percutaneous computed tomography-guided lung biopsies: preliminary results using an augmented reality navigation system.

AIMS AND BACKGROUND: "Augmented reality" is a technique to create a composite view by augmenting the real intervention field, visualized by the doctor, with additional information coming from a virtual volume generated using computed tomography (CT), magnetic resonance or ultrasound images previously acquired from the same patient. In the present study we verified the accuracy and validated the clinical use of an augmented reality navigation system produced to perform percutaneous CT-guided lung biopsies. METHODS: One hundred and eighty consecutive patients with solitary parenchymal lung lesions, enrolled using a nonrandom enrollment system, underwent percutaneous CT-guided aspiration and core biopsy using a traditional technique (group C, 90 patients) and navigation system assistance (group S, 90 patients). For each patient we recorded the largest lesion diameter, procedure time, overall number of CT scans, radiation dose, and complications. The entire experimental project was evaluated and approved by the local institutional review board (ethics committee). RESULTS: Each procedure was concluded successfully and a pathological diagnosis was reached in 96% of cases in group S and 90% of cases in group C. Procedure time, overall number of CT scans and incident x-ray radiation dose (CTDIvol) were significantly reduced in navigation system-assisted procedures (P <0.001; z = 5.64) compared with traditional CT-guided procedures. The percentage of procedural complications was 14% in group S and 17% in group C. CONCLUSION: The augmented reality navigation system used in this study was a highly safe, technically reliable and effective support tool in percutaneous CT-guided lung biopsy, allowing to shorten the procedure time and reduce the incident x-ray radiation dose to patients and the rate of insufficient specimens. Furthermore, it has the potential to increase the number of procedures executed in the allocated time without increasing the number of complications.

Neuroendocrine tumor presenting like lymphoma: a case report.

INTRODUCTION: Neuroendocrine tumors are a rare but diverse group of malignancies that arise in a wide range of organ systems, including the mediastinum. Differential diagnosis includes other masses arising in the middle mediastinum such as lymphoma, pericardial, bronchogenic and enteric cysts, metastatic tumors, xanthogranuloma, systemic granuloma, diaphragmatic hernia, meningocele and paravertebral abscess. CASE PRESENTATION: We present a case of 42-year-old Caucasian man with a neuroendocrine tumor of the middle-posterior mediastinum and liver metastases, which resembled a lymphoma on magnetic resonance imaging. CONCLUSION: The differential diagnosis in patients with mediastinal masses and liver lesions should include neuroendocrine tumor.

Strategies for the transfusion of subjects with complex red cell immunisation: the Bank of rare blood donors of the Region of Lombardy.

INTRODUCTION: Selecting units of rare blood for transfusion to patients with complex immunisation is one of the most critical processes of a Transfusion Centre. In January 2005 the 'Rare Blood Components Bank - Reference Centre of the Region of Lombardy' w as established with the following goals: 1) identifying regional rare blood donors; 2) creating a regional registry of rare donors; 3) organising a regional bank of liquid and frozen rare blood units; 4) setting up a regional Immunohaematology Reference Laboratory (IRL) to type donors and resolve complex cases. METHODS: The key elements in establishing the Bank were periodic meetings organised by the directors and representatives of the regional Departments of Transfusion Medicine and Haematology (DTMH) and the institution of three working groups (informatics, regulations, finance). RESULTS: The regional IRL was set up, the relevant operating procedures were distributed region-wide, software features were defined and later validated upon activation, and the funds assigned were allocated to various cost items. The number and characteristics of the donors to be typed were identified and 14 regional DTMHs started to send samples. Overall, 20,714 donors were typed, for a total of 258,003 typings, and 2,880 rare donors were identified. Of these, 97% were rare donors because of combinations of antigens (2,139 negative for the S antigen and 659 negative for the s antigen) and 3% (n=82) because they were negative for high-frequency antigens. In the first 2 years of activity, the IRL carried out investigations of 140 complex cases referred from other Centres and distributed 2,024 units with rare phenotypes to 142 patients. CONCLUSIONS: The main goal achieved in the first 24 months from the start of the project was to set up a regional network able to meet the transfusion needs of patients with complex immunisation.

High prevalence of a screening-detected, HFE-unrelated, mild idiopathic iron overload in Northern Italy.

BACKGROUND AND OBJECTIVES: In Italy, typical HFE mutations account for only 64% of the cases with overt hereditary hemochromatosis (HH), and a common HFE-unrelated disease was hypothesized. DESIGN AND METHODS: One thousand and fifty potential blood donors were screened by iron tests, C282Y and H63D HFE mutation analysis in a region in North Italy. Subjects with repeated fasting transferrin saturation of 45% or more and no secondary iron overload were defined as probands with idiopathic iron overload. To assess the inheritance of iron overload, relatives of probands were screened. RESULTS: The overall frequency of probands with idiopathic iron overload was 3.43% (95% confidence interval, 2.32 to 4.52). Of these, 8.4% had genotypes associated with HH (compound heterozygous for H63D/C282Y or homozygous for H63D HFE mutations), and 91.6% had atypical genotypes: 47.2% were heterozygous for C282Y or H63D HFE mutations, and 44.4% had wild type/wild type genotype. A family history of iron overload was proven in 33.3% of probands with atypical genotypes (1.04% of the overall population). Pedigree analysis excluded linkage of heterozygous HFE mutations with iron overload (cumulative lod score 2.41) and documented a recessive non-HLA-linked locus accounting for iron overload in wild type/wild type genotypes. None of the probands had clinical signs of iron accumulation; in males, serum ferritin positively correlated with age (r=0.63, p<0.01), and the regression model predicted a serum ferritin of 700 ng/mL at the age of 58. INTERPRETATION AND CONCLUSIONS: In Northern Italy an HFE-unrelated, mild idiopathic iron overload is highly prevalent. A recessive locus accounts for iron overload in at least 1.04% of the overall population.

Bioética y derecho / Bioethics and law

Este texto propone una serie de observaciones y argumentos que permiten situar adecuadamente el desafíoplanteado por la bioética al derecho. El modelo de Kelsen, consistente en identificar los desafíos de la bioética como simples problemas de contenido de normas, es postulado como limitado y reduccionista respecto de las temáticas substanciales que la bioética plantea. El camino propuesto por el autor para evitar convertir la ciencia jurídica en una simple técnica, consistiría en lograr que aquella reasuma su específica validez antropológica, lo que la alejaría de toda tentación de estéril formalismo, obligándola a trabajar en la perspectiva de las estructuras que caracterizan el ser delhombre, dado que la bioética plantea problemas antropológicos generales, esto es, de estructura.