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The Investigations of this article focus on the response of an Al2O3:C radioluminescence (RL) prototype for medical dosimetry in a 6 MV photon beam. The prototype can be configured using two types of detectors coupled to fiber-optic cables - single crystal (1 x 1 x 2 mm(3)) and droplets (in two grain sizes, 38 and 4 mu m, molded in r =0.5 mm,1= 200 mu m). By using the appropriate filters in addition to time gating it is possible to remove disturbance present during irradiation: the stem effect. Pre -irradiation of the dosimeters to a dose of 300 Gy made the memory effects in Al2O3:C negligible, so as to not impair the dosimetric properties of the system. The key findings are that the system is suitable for small field beam dosimetry, while giving overall good dose response in other features (i.e., beam profile, dose rate - FF and FFF modes). The results show that our prototype can be used for real time dose rate assessment in medical photon dosimetry without many correction factors. The 41 mu m RL measurement results are in excellent agreement (i.e. below 1%) with the dose delivered according to standard beam data. (C) 2018 Elsevier B.V. All rights reserved.

Photon beams produced by a cobalt-60 Unit and a 6 MV linear accelerator equipped with stereotactic collimators were used to investigate some dosimetric properties of a radioluminescent dosimeter based on a Ce-doped optical fibre. The stability of the signal with increasing the irradiation time, enabled a reliable and real-time measurement of the dose rate. The methods, recently developed, of optical coupling, light collection and signal processing allowed to achieve a satisfactory signal to noise ratio, a good reproducibility and a linear dose-response. The punctual dimension of the doped fibre diameter was exploited in the characterization of stereotactic fields, providing results in agreement with those obtained using a micro-ionization chamber. © 2008 Elsevier Ltd. All rights reserved.

Background HCV infection beside chronic hepatitis can induce immunological disorders with different clinical expressions such as chronic arthritis. Aim To study the prevalence of arthritis in HCV-Ab positive patients and verify possible correlation with viral replication, hepatic damage and autoimmunity imbalance. Study design Three hundred and eighty patients (196 M and 184 F) affected by HCV infection were examined and 38 (10%) were selected according to the presence of arthritis. Eight of them were excluded because arthritis raised before HCV infection. Each patient, once undergone liver biopsy, was evaluated for: clinical examination (articular evolution), Rx examination, serum expression of hepatic damage (mainly ALT), viral replication, and involvement of autoimmunity (ANA, RF, crioglobulins, AKA, CCP). Results Data from patients [Lamprecht P, Gause A, Gross WL. Cryoglobulinemic vasculitis. Arthritis Rheum 1999; 42:2507–16.] with AKA and CCP positivity were not considered for statistical examination because the clear correlation between rheumatoid arthritis and these parameters. The remaining 20 patients showed hepatic damage 47%, viral replication in 74%, RF 42%, ANA 16%, crioglobulins 42% (RF positive). No correlation was evident between ANA serum concentrations and viral replication; furthermore a significant negative correlation between RF positivity and viral replication only in a subgroup of patients with serologic expression of hepatic damage was found. Conclusions These data support hypothesis that the onset of arthritis and presence of autoimmunity parameters ANA, RF are not related to the viral replication but others mechanism immunological induced by HCV might be considered.

A feasibility study for the use of a Ce3+-doped optical fibre as a radio luminescent dosimeter in radiotherapy was carried out. The prototype showed a satisfactory reproducibility (1.7%) and a good linearity over a clinically relevant dose range (from few cGy to approximately 10 Gy). Moreover, the device enabled a reliable evaluation of the absorbed dose, independently of the dose rate and of the orientation of the incoming radiation. A slight energy dependence of the response was observed when the system was irradiated with electron beams of different energies. The results indicate that the employment of this new system might be very promising both for quality control measurements and "in vivo" dosimetry. Some improvements are nevertheless still required in order to allow a real-time evaluation of the Cherenkov radiation produced by the irradiated portion of the passive optical fibre, which influences some of the dosimetric properties of the system. (c) 2006 Elsevier B.V. All rights reserved.

In this paper, errors and discrepancies in the subject paper [Cincotti et al. (2002)] are highlighted. A comment, concerning the axial resolution associated to the adopted processing procedure is also reported.

To the Editor: Streptococcus suis, a major swine pathogen worldwide, is emerging as a zoonotic agent capable of causing a variety of serious infections in swine as well as in persons exposed to pigs or to pork products. These infections include meningitis, septicemia, pneumonia, endocarditis, arthritis, and septic shock (1,2). Despite recent outbreaks among persons in China, S. suis disease in humans is a rare, probably underdiagnosed infection that usually occurs as sporadic cases (1,2). Persons in close occupational or accidental contact with pigs or pork products and those who eat uncooked or undercooked pork may be at higher risk than others. However, most infected persons are likely healthy carriers, and S. suis is believed to induce overt disease (especially meningitis) in only some circumstances (2). We describe a case of S. suis meningitis in a 68-year-old man from Sardinia, Italy, who had no reported contact with swine, other animals, or any animal products; the patient also had cancer, which was discovered incidentally during the workup. In November 2007, the patient was hospitalized with a 48-hour history of fever, headache, nausea, and general malaise. Physical examination showed impaired consciousness, nuchal rigidity, and a temperature of 39.5°C. Laboratory findings were 20,700 leukocytes/mm3 with 92% neutrophils, glucose 95 mg/dL, and C-reactive protein 375 mg/L. Cerebrospinal fluid (CSF) analysis demonstrated 240 leukocytes/μL with 80% polymorphonuclear cells, glucose 24 mg/dL, and protein 277 mg/dL. A computed tomography scan of the head showed no abnormal findings. Gram stain of CSF showed gram-positive cocci, mostly in pairs (Figure). Figure Gram-positive cocci, mostly in pairs, in cerebrospinal fluid from a 68-year-old man with Streptococcus suis meningitis. Magnification ×1,000. Empirical therapy consisted of intravenous ceftriaxone (2 g twice a day) and oral chloramphenicol (2 g once a day). On day 5, α-hemolytic streptococci were isolated from CSF on sheep blood agar and identified as S. suis by using APIStrep (bioMerieux, Marcy l’Etoile, France). Serotyping, performed by slide agglutination with specific antiserum (Statens Serum Institute, Copenhagen, Denmark), identified the isolate as serotype 2. Antimicrobial drug­­–susceptibility testing, performed according to guidelines of the Clinical and Laboratory Standards Institute (www.clsi.org), indicated susceptibility to penicillin, ceftriaxone, chloramphenicol, levofloxacin, and vancomycin and resistance to erythromycin (MIC >128 mg/L) and tetracycline (MIC 16 mg/L). Erythromycin resistance was constitutive and was mediated by the erm(B) determinant; tetracycline resistance was mediated by tet(W). Multilocus sequence typing (http://ssuis.mlst.net) assigned the S. suis isolate to sequence type (ST) 1. The patient, a retired welder, denied any recent occupational or even occasional contact with swine or other animals and had no history of eating raw or undercooked pork. The patient’s condition improved; chloramphenicol was discontinued on day 10, but the 14-day course of ceftriaxone was completed. On day 6, the patient became afebrile but had dizziness and deafness; a formal audiology evaluation on day 9 showed severe bilateral sensorineural high-frequency hearing loss (–80 dB) that improved after a short course of dexamethasone. However, the patient was not discharged because of the lung mass found on initial chest radiograph. Computed tomography scan, bronchoscopy, and histopathologic findings led to diagnosis of the mass as an advanced-stage squamous cell carcinoma. The meningitis had common and uncommon features. The common features were hearing loss, a typical outcome of S. suis meningitis independent of early antimicrobial drug administration (1,2); serotype 2, the most frequent and virulent serotype in swine and in humans (1,2); ST1, belonging to the ST1 complex, strongly associated with S. suis meningitis isolates (2,3); and erm(B)-mediated erythromycin resistance, widespread in this species (4). The uncommon features were tetracycline resistance mediated by tet(W), increasingly detected in gram-positive and in gram-negative bacteria (5) but never previously reported in S. suis or in other major streptococcal pathogens, where common determinants are tet(M) and tet(O); and lack of evidence for recent contact with swine, other animals, or swine (pork) products. Two previous cases of human S. suis meningitis in Italy (6,7) and other recent cases from Europe (8,9) were related to occupational exposure. However, the patient reported here also had cancer, and malignancy has been indicated as a predisposing factor for the development of severe S. suis disease in humans (2). These findings appear to be consistent with the recent suggestion of new epidemiologic patterns of infection caused by this organism (2). S. suis may become an opportunistic pathogen in persons who are under stress or who have immunodeficiency, and it has been increasingly isolated from mammalian species other than pigs, from birds, and from the environment. As also discussed in a recent survey (10), the possibility cannot be excluded that a patient with S. suis infection may be unaware or have no memory of previous exposure to animals. Alternatively, because asymptomatic carriage of S. suis has been documented in humans (2) and is believed to contribute to its transmission (10), the possibility should also be considered that the infection may be a reactivation, possibly favored by malignancy, of latently colonizing S. suis.

Ultrasound beams propagating in biological tissues undergo distortions due to local inhomogeneities of the acoustic parameters and the nonlinearity of the medium. The spectral analysis of the radio-frequency (RF) backscattered signals may yield important clinical information in the field of tissue characterization, as well as enhancing the detectability of tissue parenchymal diseases. Here, the authors propose a new tissue spectral imaging technique based on the wavelet packets (WP) decomposition. In a conventional ultrasound imaging system, the received echo-signals are generally decimated to generate a medical image, with a loss of information. With the proposed approach, all the RF data are processed to generate a set of frequency subband images. The ultrasound echo signals are simultaneously frequency decomposed and decimated, by using two quadrature mirror filters, followed by a dyadic subsampling. In addition, to enhance the lesion detectability and the image quality, the authors apply a nonlinear filter to reduce noise in each subband image. The proposed method requires simple additional signal processing and it can be implemented on any real-time imaging system. The frequency subband images, which are available simultaneously, can be either used in a multispectral display or summed up together to reduce speckle noise. To localize the different frequency response in the tissues, the authors propose a multifrequency display method where 3 different subband images, chosen among those available, are encoded as red, green, and blue intensities (RGB) to create a false-colored RGB image. According to the clinical application, different choices can evidence different spectral proprieties in the biological tissue under investigation. To enhance the lesion contrast in a grey-level image, one of the possible methods is the summation of the images obtained from narrow frequency subbands, according to the frequency compounding technique. The authors show that by adding the denoised subband images created with the WP decomposition, the contrast-to-noise ratio in 2 phantom images is largely increased.

The nominal 50 kg h −1 dry coal biodepyritization pilot plant was built at Porto Torres (Sassari, Italy) in the area of EniChem S.p.A. Chemical Works, with financial support of the Commission of European Communities and with the participation of the DMT of Essen (Germany), the Mining and Mineral Processing Department of the University of Cagliari (Italy), the Technical University of Delft (The Netherlands) and the Warren Spring Laboratory of Stevenage (UK). The plant went on stream in early September 1992. Test runs were carried in the range 6.5–41.5% solids concentration. For every solids concentration the steady state was attained in about 10 d. For all the test runs the assays showed that more than 90% pyrite removal is achieved in the first five bioreactors; for a pulp flow rate of 6.94 × 10 −2 dm 3 s −1 , (250 l h −1 ) and useful bioreactor volume of 7.5 m 3 , this corresponds to a residence time of 540 345 s, i.e., 6.254 d, and to a pyritic iron biosolubilization rate of 36 mg dm −3 h −1 . The pyrite biosolubilization rate constant is 1.53 × 10 −2 h −1 . The power input per bioreactor operating on a 40% solids pulp is 4 kW with cos Φ = 0.76. Hence, the power required for processing 100 kg h −1 coal at 40% solids in the bioreactor section is 4 × 5 = 20 kW h, i.e. 200 kW h per tonne dry coal.

Solids concentration is a critical technico-economic parameter in biohydrometallurgical processing since it decisively affects bioreactor size and therefore investment and operating costs. Researchers have repeatedly provided evidence, since the early times of biohydrometallurgy, that bioreactor leaching rates of metal sulphide concentrates drastically decrease whenever percent solids concentration exceeds 16–20. This limitation, should it hold also for coal biodepyritization processes, would place a serious constraint on their economics. The paper presents the results of an investigation carried out running in parallel three different types of laboratory reactors fed with the same pulp processed in the 7.5 m 3 stirred-tank reactors (STRs) installed in the Porto Torres coal biodepyritization pilot plant. Evidence is provided that biodepyritization performance of the reactors remains practically unchanged in the solids concentration range from 5% to 40%, whereas failure of pure pyrite bioleaching at 30% solids concentration is observed in the same reactors. This result seems to support the view that solids concentration influence on bioleaching performance is related to the proportion of oxidizable mineral present in the solid phase. Comparison of laboratory- and semi-commercial-scale STRs seems to show that scale-up imparts an improvement in machine performance.

Objective. Since brain perfusion abnormalities have been described by single-photon emission computed tomography in some autoimmune diseases, the aim of the present study was to evaluate the incidence of perfusion abnormalities by brain single-photon emission computed tomography in a group of coeliac disease patients, and to investigate whether gluten intake and associated autoimmune diseases may be considered risk factors in causing cerebral impairment. Methods. Thirty-four adult coeliac patients (16 on a gluten-free diet and 18 on a gluten-containing diet, 18 (53%) with autoimmune diseases) underwent 99 m Tc -ethyl cysteinate dimer brain single-photon emission computed tomography and qualitative evaluation of brain perfusion was performed together with a semiquantitative estimation using the asymmetry index. Ten subjects on our database, matched for sex, age and ethnic group, who were proved normal by histology of jejunal mucosa (four males and six females; median age 39 years, range 27–55 years), were included as control group. Results. Twenty-four out of 34 patients (71%) showed brain single-photon emission computed tomography abnormalities confirmed by abnormal regional asymmetry index (>5%; range 5.8–18.5%). Topographic comparison of the brain areas showed that the more significant abnormalities were localised in frontal regions, and were significantly different from controls only in coeliac disease patients on unrestricted diet. The prevalence of single-photon emission computed tomography abnormalities was similar in coeliac disease patients with (74%) and without (69%) associated autoimmune disease. Conclusions. Abnormalities of brain perfusion seem common in coeliac disease. This phenomenon is similar to that previously described in other autoimmune diseases, but does not appear to be related to associated autoimmunity and, at least in the frontal region, may be improved by a gluten-free diet.

Background Bone and joint scan using 99mTc-MDP is often used in rheumatologic practice, but there is little data on its effective relevance in evaluating chronic articular inflammatory diseases. Objectives The aim of this work has been to compare bone scan results against clinical evidence of joint inflammatory involvement, evaluating with both approaches the number of affected joints (NAJ) in a group of patients with rheumatoid arthritis (RA) or osteoarthritis (OA). Methods Bone scan was carried out in 75 consecutive patients (44 RA, 31 OA). The nuclear medicine specialist indicated in the report the list of joints showing uptake. In the same patients (without knowing the results of scintigraphy) a rheumatologist diagnosed the NAJ on the basis of clinical signs of inflammation. Then the patients were stratified in 2 * 2 tables according to the prevalence of clinical evidence or scintigraphic uptake. Results The distribution was found to be not significant (chi-square = 1.6, p = 0.2). The percentage of patients without uptake was only 5.3%. In 33 patients (44%) no clinical evidence was observed. Among these, 30 showed articular uptake (in an average of 7.0 * 4.6 joints). Considering only the patients with clinical evidence, the subjects with articular uptake were 41 out of 42 (97.6%) with an average of 8.6 * 4.6 involved joints. In these patients the ratio between number of joints with uptake and number of joints with clinical evidence (ratio uptake/clinical) was then calculated for each subject. Such a ratio resulted in an average of 2.9 * 3.6. These results were also confirmed analysing the data by sex, disease (RA or OA) and class of therapy. We then decided to assess if the greater prevalence of involved joints obtained with bone scan was correlated with an increase of inflammatory indexes. Taking into consideration the patients with clinical evidence, we performed multiple regression analysis using as dependent variable in distinct models the ratio uptake/clinical, the number of joints with clinical evidence and the number of joints showing uptake. The inflammatory indexes (ESR and CRP) were used as independent variables and age, sex, diagnosis and therapy were used as covariates. The uptake/clinical ratio did not show any significant correlation. The number of joints with clinical evidence correlates with ESR, those ones showing uptake correlates only with age, both with direct correlation. Conclusion The data obtained indicates that the articular scintigraphic uptake in AR and OA, on average, highlights a significantly higher number of joints involved as compared to the clinical test. It still remains to be defined if this is an overestimation related to the characteristics of the scan or if it is the sign of a higher sensibility in highlighting the inflammation location. An element of caution against the second hypothesis is established by the absence of correlation with the inflammatory indexes.

Earlier investigations on laboratory and pilot plant scale have shown the resort to microorganisms to be a practicable approach to the problem of purifying mineral dressing plant reject waters from residual flotation reagents and/or metal ions. In spite of the proven effectiveness of this method, one major drawback, namely the pathogenicity of some microorganisms, has so far hampered its application on a commercial scale. A research programme, aimed at developing a microbial reject water purification technique utilizing non-pathogenic strains was thus drawn up and is currently being implemented. Strains such as Bacillus subtilis, Saccharomyces cerevisiiae, Bifidobacterium bifidum, Lactobacillus acidophilus and Acinetobacter calcoaceticus , which are not harmful to human health, some of them being commonly found in the human intestine, have been successfully tested for removing alkylsulphates, alkylamines and fany acids from solutions simulating flotation plant tailings waters. Removals as high as 90% in less than 48 h can be easily achieved with no nutrient requirements, since in most cases the flotation reagent residue to be removed is metabolized by the microorganisms themselves.

21184 Background: The prognostic value of flow cytometry DNA ploidy and Ki-67 expression in colorectal carcinomas has not been defined yet. The study tries to correlate tumoral DNA ploidy and proliferative activity (Ki-67) with therapy response, Overall Survival (OS), Disesase Specific Survival (DSS) and Disease Free Survival (DFS). Methods: From 01/09/02 to 30/06/05, 3 samples of cancer tissue and 1 sample of normal mucosa has been collected from all operating pieces of colorectal cancer. These samples were frosen and later disgregated, treated and coloured with Propidium Iodide. DNA ploidy was evaluated by FACSCalibur cytofluorimetry. Normal mucosa tissue was our internal control. Ki-67 was evaluated by immuno-histochemistry in all tumoral samples. All the patients were cured with chemo- and/or radiotherapy in our divisions. Results: 67 patients (M/F 35/32); median age was 70; staging: 19% I, 33% II, 30% III, 18% IV. We found aneuploidy in 65,7% of carcinoma and Ki-67 median expression was 55%. DNA tumoral heterogeneity was present in 27% of patients. DNA aneuploidy correlates with advanced disease stage at diagnosis (p55%) do not show evident disease versus 100% of patients with DNA diploidy and lower Ki-67. Tumoral aneuploidy correlates in a significative way with lower OS (48% vs 89% of diploid patients), lower DSS (tumor death happened just in patients with aneuploid DNA in every disease stages), with lower DFS (18% vs 86% of diploid patients). Univariated analysis stated that aneuploidy determinates an Odd Ratio=5,7 to develop disease progression (p=0,033). At the moment Ki-67 expression with 55% cut-off does not seem to correlate with OS, DSS and DFS. Conclusions: Preliminar results (the study is still in progress) seem to suggest that cytofluorimetric DNA-ploidy has a prognostic and predictive significance in colo-rectal carcinomas. Ki-67 expression (immuno-histochemistry) has an uncertain significance. The small number of patients and the short follow-up do not allow us to reach any definitive conclusions, but the study is worth to go on. No significant financial relationships to disclose.