Antibiotic consumption is a major driver of antibiotic resistance in calves raised on Italian cow-calf beef farms.

Although its importance, little information is available on antibiotic-resistance in cow-calf beef farms. This study aimed to determine prevalence and risk factors for antibiotic-resistant organisms in this livestock system. Fifty-four farms from Central Italy were included to assess the presence of antibiotic-resistant indicator Escherichia coli and of ESBL and/or AmpC-producing E. coli (ESBL/AmpC-EC) in calves. Antimicrobial usage (AMU) was recorded, and farm-related variables were collected through questionnaires. Potential risk factors were tested using a mixed-effects logistic regression model. The presence of resistant-E. coli was recorded in 75.9% of farms (95% confidence interval [CI]: 62.4-86.5) with resistance to tetracyclines, sulfonamides, penicillins, and fluoroquinolones as the most frequent. The prevalence of farms positive for ESBL/AmpC-EC was 35.2% (95% CI: 22.7-49.4). AMU on the farms originating a resistant-E. coli was higher than that on the farms originating a susceptible-E. coli. The same difference was found for the consumption of beta-lactams (beta-DCD/year) and AMU via the parenteral route, which resulted also associated with the presence of ESBL/AmpC-EC. Farms with higher beta-DCD/year had an increased risk of being positive for resistant-E. coli, whereas farms with higher overall AMU had an increased risk for ESBL/AmpC-EC presence. Among farm-related factors, only farm size was associated with the presence of ESBL/AmpC-EC (odds ratio: 5.8, 95% CI: 1.3-26.3). Our findings highlight a reduction of the risk of ESBL/AmpC-EC in small cow-calf farms, and a strong association between AMU and antibiotic-resistance. Antibiotic stewardship programs are needed to improve the health status of cow-calf farms and ensure their long-term sustainability.

A cryogenic magneto-optical device for long wavelength radiation.

We present here a small-scale liquid helium immersion cryostat with an innovative optical setup suitable to work in long wavelength radiation ranges and under an applied magnetic field. The cryostat is a multi-stage device with several shielding in addition to several optical stages. The system has been designed with an external liquid nitrogen boiler to reduce liquid bubbling. The optical and mechanical properties of the optical elements were calculated and optimized for the designed configuration, while the optical layout has been simulated and optimized among different configurations based on the geometry of the device. The final design has been optimized for low-noise radiation measurements of proximity junction arrays under an applied magnetic field in the wavelength range λ = 250 µm-2500 µm.

Pilot survey of norovirus in Northern Italy: an example of surveillance of norovirus gastroenteritis.

In this study, we describe the results of virological investigations carried out on cases of gastroenteritis reported in different communities within a 2-year pilot surveillance programme (January 2012 to December 2013) in the autonomous province of Bolzano (Northern Italy). Among the 162 norovirus (NoV)-positive cases out of 702 cases investigated, 76 were grouped in nine suspected outbreaks, 37 were hospital-acquired and 49 were community-acquired sporadic cases. NoV infections were found in all age groups in outbreak and community-acquired cases, while the highest peak of hospital-acquired infections occurred in the elderly. Sequence analyses helped to identify suspected outbreaks both in the community and in hospital wards. Although GII.4 is the predominant genotype, sequence data confirmed that at least seven genotypes circulate causing sporadic cases. Findings in this study confirmed the relevance of NoV infections as a cause of outbreaks, and impact of NoV infections in community-acquired sporadic cases in adults that are rarely described because of a lack of reporting.

Exposures from nuclear medicine diagnostic procedures: the dose impact on the Aosta Valley population.

The present work evaluates the per-procedure, annual collective and per-capita effective doses to the Aosta Valley region population from nuclear medicine (NM) examinations performed from 2005 to 2011 at the regional NM department. Based on its demographical and socioeconomics characteristics, this area can be considered as representative of the level I countries, as defined by the United Nations Scientific Committee on the Effects of Atomic Radiation. The NM per-procedures effective doses were within the range of 0.018-35 mSv. A steady frequency per 10 000 inhabitants has been observed, together with a decrease for thyroid and whole-body bone scintigraphy. Myocardial and bone scintigraphy studies were the major contributors to the total collective effective dose. The mean annual collective and per-capita effective doses to the population were 15 man Sv y(-1) and 120 µSv y(-1), respectively. The NM contribution to the total per-capita effective dose accounts for 5.9 % of that due to the medical ionising radiation examinations overall.

Technical note: patient-specific quality assurance methods for TomoDirect(TM) whole breast treatment delivery.

PURPOSE: To investigate the feasibility of implementing a novel approach for patient-specific QA of TomoDirect(TM) whole breast treatment. METHODS: The most currently used TomoTherapy DQA method, consisting in the verification of the 2D dose distribution in a coronal or sagittal plane of the Cheese Phantom by means of gafchromic films, was compared with an alternative approach based on the use of two commercially available diode arrays, MapCHECK2(TM) and ArcCHECK(TM). The TomoDirect(TM) plans of twenty patients with a primary unilateral breast cancer were applied to a CT scan of the Cheese Phantom and a MVCT dataset of the diode arrays. Then measurements of 2D dose distribution were performed and compared with the calculated ones using the gamma analysis method with different sets of DTA and DD criteria (3%-3 mm, 3%-2 mm). The sensitivity of the diode arrays to detect delivery and setup errors was also investigated. RESULTS: The measured dose distributions showed excellent agreement with the TPS calculations for each detector, with averaged fractions of passed Γ values greater than 95%. The percentage of points satisfying the constraint Γ < 1 was significantly higher for MapCHECK2(TM) than for ArcCHECK(TM) and gafchromic films using both the 3%-3 mm and 3%-2 mm gamma criteria. Both the diode arrays show a good sensitivity to delivery and setup errors using a 3%-2 mm gamma criteria. CONCLUSIONS: MapCHECK2™ and ArcCHECK(TM) may fulfill the demands of an adequate system for TomoDirect(TM) patient-specific QA.

Effective dose delivered by conventional radiology to Aosta Valley population between 2002 and 2009.

OBJECTIVE: Medical diagnostic procedures can be considered the main man-made source of ionising radiation exposure for the population. Conventional radiography still represents the largest contribution to examination frequency. The present work evaluates procedure frequency and effective dose from the majority of conventional radiology examinations performed at the Radiological Department of Aosta Hospital from 2002 to 2009. METHOD: Effective dose to the patient was evaluated by means of the software PCXMC. Data provided by the radiological information system allowed us to obtain collective effective and per caput dose. RESULTS: The biggest contributors to per caput effective dose from conventional radiology are vertebral column, abdomen, chest, pelvis and (limited to females) breast. Vertebral column, pelvis and breast procedures show a significant dose increment in the period of the study. The mean effective dose per inhabitant from conventional radiology increased from 0.131 mSv in 2002 to 0.156 mSv in 2009. Combining these figures with those from our study of effective dose from CT (0.55 mSv in 2002 to 1.03 mSv in 2009), the total mean effective dose per inhabitant increased from 0.68 mSv to 1.19 mSv. The contribution of CT increased from 81% to 87% of the total. In contrast, conventional radiology accounts for 85% of the total number of procedures, but only 13% of the effective dose. CONCLUSION: The study has demonstrated that conventional radiography still represents the biggest contributor to examination frequency in Aosta Valley in 2009. However, the frequency of the main procedures did not change significantly between 2002 and 2009.

Population exposure to ionising radiation from CT examinations in Aosta Valley between 2001 and 2008.

Recent and continuous advances in CT, such as the development of multislice CT, have promoted a rapid increase in its clinical application. Today, CT accounts for approximately 10% of the total number of medical radiographic procedures worldwide. However, the growing performance of the new CT generations have increased not only the diagnostic opportunities, but also the radiation dose to the patient. The relative contribution to the collective radiation dose is now estimated to be approximately 50%. Several papers have been published concerning the intensive use of CT and its contribution to the collective dose. However, most of the literature concerns the years 1997-2003 and the dosimetric evaluations are generally limited to the main standard protocols (chest, head and abdomen), deriving the effective dose by the simple application of the diagnostic reference levels. Only specific dosimetric analyses of single and innovative procedures have been published recently. Moreover, few data comes from Italian radiology departments. This paper aims to bridge these gaps. Firstly, it characterises in terms of measured CT dose index (CTDI) two last-generation scanners of the Radiological Department of Aosta Hospital. Secondly, it evaluates the effective dose from most of the CT examinations performed from 2001 to 2008 to compare protocols and technologies in line with the suggestions of the 2007 Recommendations of the International Commission on Radiological Protection, Publication 103. Finally, it estimates the collective dose to the population.

Dose reduction in multislice CT by means of bismuth shields: results of in vivo measurements and computed evaluation.

PURPOSE: We investigated the amount of patient dose reduction in the thyroid, lens of the eye and the breast when using bismuth protections in multislice computed tomography (CT) exams as well as their influence on the quality of diagnostic images. MATERIALS AND METHODS: The radiation dose was measured by using thermoluminescence dosimeters. The study was conducted on the two CT scanners installed in our radiology department (64 and eight slices). The shield effects on the CT image were evaluated by measuring the signal-to-noise ratio in a phantom and in vivo, and by verifying the presence of artefacts on patients' images. The obtained organ-dose reduction factors were used to evaluate the effects of shielding on the effective dose. RESULTS: The shielding attenuation ranged from 30% to 60% depending on the CT scan protocols and organs. The difference between shielded and unshielded signal-to-noise ratio was statistically significant but within the standard requirements for quality assurance. Results were in agreement with the radiologists' perception of image quality. The use of the shields allowed up to 38% reduction of effective dose. CONCLUSIONS: Use of bismuth shields significantly decreases both organ and effective radiation dose, with a consequent reduction in health risk for the patient, quantified in 1.4 fewer cases of radiation-induced tumours every 5 years in our centre (12,100 exams/year), in agreement with the risk factors proposed by Publication 60 of the International Commission on Radiological Protection (ICRP). The relative inexpensiveness of these protections, their easy application and their substantial lack of influence on image quality suggest their massive introduction into routine clinical practice.

Static and ELF magnetic fields enhance the in vivo anti-tumor efficacy of cis-platin against lewis lung carcinoma, but not of cyclophosphamide against B16 melanotic melanoma.

Previous works showed that exposure to static and extremely low frequency (ELF) magnetic fields (MF) over 3 mT slows down the growth kinetics of human tumors engrafted s.c. in immunodeficient mice, reducing their metastatizing power and prolonging mouse survival. In the experiments reported here, immunocompetent mice bearing murine Lewis Lung carcinomas (LLCs) or B16 melanotic melanomas were exposed to MF and treated respectively with two commonly used anti-cancer drugs: cis-diamminedichloroplatinum (cis-platin) and N,N-bis (2-chloroethyl)tetra-hydro-2H-1,3,2-oxazaphosphorin-2-amine 2-oxide (cyclophosphamide). The experiment endpoint was survival time. The survival time of mice treated with cis-platin (3mg/kg i.p.) and exposed to MF was significantly (P<0.01) longer than that of mice treated only with cis-platin or only exposed to MF, superimposing that of mice treated with 10mg/kg i.p. of the drug, showing that MF act synergically with the pharmacological treatment. On the contrary, when mice treated with cyclophosphamide (50mg/kg i.p.) were exposed to MF no synergic effects were observed, the survival curve being exactly the same as that of mice treated with the drug alone. No clinical signs or toxicity were seen in any of the mice exposed to MF alone or along with cis-platin or cyclophosphamide treatment, compared to mice given only the two known drugs.A possible explanation for the synergic effect of MF being found in mice treated with cis-platin could be that the platinum ion stimulates radical production and that MF enhance active oxygen production bringing about changes in tumor cell membrane permeability, influencing positively the drug uptake. Alternatively, or in addition to this, it has been demonstrated that the rate of conversion of cis-platin to reactive species able to bind to DNA, is increased by localized production of free radicals by MF.

[A quality control test of the image obtained with electronic portal imaging devices]. / Verifica della qualità dell'immagine ottenuta mediante sistemi di imaging portale elettronico.

INTRODUCTION: A quality control of the digital image obtained from two electronic portal imaging devices is discussed. The devices are used to verify the radiotherapic treatment setup by comparing online images of the irradiated volume with those of the simulation devices. MATERIAL AND METHODS: Both iView and Target View devices, respectively installed on a dual energy SLi Precise Elekta and Saturne 42 Ge linear accelerators, consist of highly efficient phosphor screen and high quality videocamera, controlled by a workstation, able to generate digital portal images from few cGy doses. A phantom and software package are used to assess the spatial resolution and signal to noise ratio, and to compare tha data obtained. Spatial resolution and signal to noise ratio of both systems were studied as a function of energy, gantry angle and image acquisition parameters. RESULTS: The mean spatial resolutions obtained from the first 30 measurements were 0,265+/-0,012 and 0,220+/-0,010 lp/mm respectively for 6 and 18 MV of Saturne 42 (Target View) and 0,241+/-0,006 and 0,239+/-0,005 lp/mm for 4 and 6 MV of SLi (iView). Spatial resolution decreases as a function of energy, meanwhile there are no significant statistical differences as regards of the acquisition parameters; signal to noise ratio, instead, increases with integration time. Different values of the spatial resolution as a function of gantry angle are due to changes in the screen-camera distance and flexing of the detector housing. The quality control test is performed every 15 days by the technicians of our Radiotherapy Department. We set the reject level of spatial resolution and signal to noise ratio to be three standard deviations below the mean value obtained during the initial EPID characterization: if the measures fall below these values preventative maintenance is scheduled. CONCLUSIONS: The efficacy of the use electronic portal imaging devices for visualizing and quantifying the relative positions of anatomical structures within the radiation field depends on the image quality. It is therefore essential to devise quality control tests for the devices themselves, to guarantee an optimal level of system performance in a fast and efficient manner.

Static and ELF magnetic fields induce tumor growth inhibition and apoptosis.

The ability of static and extremely low frequency (ELF) Magnetic Fields (MF) to interfere with neoplastic cell function has been evaluated. In vitro experiments were carried out to study the role of MF characteristics (intensity, frequency, and modulation) on two transformed cell lines (WiDr human colon adenocarcinoma and MCF-7 human breast adenocarcinoma) and one nontransformed cell line (MRC-5 embryonal lung fibroblast). Increase in cell death morphologically consistent with apoptosis was reported exclusively in the two transformed cell lines. Cell-death induction was observed with MF of more than 1 mT. It was independent of the MF frequency and increased when modulated MF (static with a superimposition of ELF at 50 Hz) were used. Based on the in vitro results, four different MF exposure characteristics were selected and used to treat nude mice xenografted with WiDr cells. The treatment of nude mice bearing WiDr tumors subcutaneously. with daily exposure for 70 min to MF for 4 weeks caused significant tumor growth inhibition (up to 50%) by the end of the treatment when modulated MF were used for at least 60% of the whole treatment period and the time-averaged total MF intensity was higher than 3.59 mT. No toxic morphological changes induced by exposure were observed in renewing, slowly proliferating, or static normal cells. A discussion on the possible biophysical mechanism at the base of the observed biological results is also offered.

[Physical-dosimetric characterization of a multi-leaf collimator system for clinical implementation in conformational radiotherapy]. / Caratterizzazione fisico-dosimetrica di un sistema di collimazione multilamellare per l'impiego clinico nella radioterapia conformazionale.

INTRODUCTION: In the present paper we discuss the main dosimetric characteristics of the multileaf collimator (MLC) installed on the Elekta SLi Precise accelerators. To evaluate the effectiveness of the MLC in conformal radiotherapy, beam transmission through leaves and/or diaphragms, leakage between the leaves, central axis depth dose, surface dose, effective penumbra, scalopping effect and field size factors were measured. MATERIALS AND METHODS: The MLC installed on the dual energy (4 and 6 MV) linear accelerator Elekta SLi Precise consists of 40 opposed pairs of 75 mm thick tungsten leaves, set in two raws mounted in place of the upper collimator. Each leaf has a nominal projected width of 10 mm. The maximum field size attainable is 40 x 40 cm2 at 100 cm SAD. Beam transmission through leaves and/or diaphragms and field size factors were measured in RW3 phantom with a ionization chamber, leakage between the leaves and effective penumbra were instead evaluated with radiographic films (X-Omat-V) and a laser scanning photodensitometer. Percentage depth doses were measured in an automatic water phantom. RESULTS: For both energies, approximately 1% of the incident radiation on the multileaf collimator is transmitted through the backup collimator, while the transmission through the different combinations of leaves and collimators is between 0.03 and 0.14%. These values show a good agreement with literature data and are in general lower than the peak values specified by the manufacturer. The peak value of the leakage between the leaves was about 2% for both energies, without significative variation with gantry or collimator angle or distance from the axis. MLC shaped fields show a skin dose less (about 3%) than the one of cerrobend block shaped fields, because of the electronic contamination due to the plexiglass tray of the cerrobend blocks; in both cases, the depth doses are similar, as are flatness and symmetry of irradiation fields. The effective penumbra increases with field dimension, depth and leaves positioning, with a mean value of about 9 mm for both energies. The different beam configurations do not significantly affect the values of the field size factors. CONCLUSIONS: The dosimetric characteristics and the case of use of the Elekta multileaf collimator make its application to conformal radiotherapy convenient and reliable, able to improve the accuracy and the effectiveness of radiation therapy and to develop new kinds of treatments. However, because of the complexity of the MLC, its implementation in radiotherapic practice requires careful dosimetric characterization to evaluate those parameters (transmission, penumbra and output factors) that play a fundamental role in the accuracy of the treatment.

Electric field and current density distributions induced in an anatomically-based model of the human head by magnetic fields from a hair dryer.

We have used the impedance method to calculate the induced electric (E) fields and current densities (J) for the spatially varying vector magnetic fields due to a hair dryer. In this method, applicable for low-frequency exposures where the quasi-static approximation may be made, the biological body or the exposed parts thereof are represented by a three-dimensional (3-D) network of impedances whose individual values are obtained from the electrical properties sigma, epsilon r for the various tissues. We have measured the 3-D variations of the 50-Hz magnetic fields from a typical hair dryer and found that the various components correlate well with those for a helical coil. The non-uniform magnetic fields thus obtained are used to calculate the induced E and J with a resolution of 1.31 cm for the model of the head and neck. The induced E values are compared with the fields endogenous to the body and the minimum detectable E-field limits based on the cellular thermal noise model proposed by Weaver and Astumian (1990, 1992).

Spectral analysis of magnetic fields from domestic appliances and corresponding induced current densities in an anatomically based model of the human head.

Magnetic fields emitted by electric appliances such as razors, hair dryers, and drills were measured in the frequency domain. Results show the presence of high-frequency components (up to 96 kHz for razors, up to 3.4 kHz for hair dryers, and up to 8.6 kHz for drills) in the harmonic content of the fields. The measured fields were used to calculate the induced current densities in an anatomically based model of the human head (resolution 1.31 cm) by using the impedance method. The harmonic field contribution to the current density was higher than that from the carrier frequency for all the tested appliances.

Extremely-low-frequency and very-low-frequency magnetic fields emitted by video display units.

Extremely-low-frequency (ELF) and very-low-frequency (VLF) magnetic fields as emitted by monochrome and multichrome video display units (VDUs) were measured for their frequency domains. The rms magnetic-flux densities (MFDs) were measured as a function of distance from all six sides of VDUs of four types. The MFDs at a distance of 30 cm from the screen (defined as the operator's position) were between 0.06 and 0.6 microT in the ELF range and between 0.02 and 0.06 microT in the VLF range. The contribution of harmonics to the total MFD was the same for both frequency ranges, less than 6%. For the first three harmonics, the MFD of each higher harmonic was one-half that of the immediately lower harmonic.

[Cutis marmorata telangiectasica congenita. Description of 2 further cases]. / Cutis marmorata telangiectasica congenita. Descrizione di due nuovi casi.

We report two cases of C.M.T.C., a rare cutaneous vascular anomaly, which is manifested at birth. It is a rare birth defect of unknown etiology; usually occurs sporadically. There is an association of C.M.T.C. with other congenital anomalies in at least 50% of the patients. On the basis of two cases, the clinical features of cutis marmorata telangiectasica congenita are described and the differential diagnosis discussed.

[Space and time in rooming-in: a survey among mothers]. / Spazi e tempi del Rooming-in: un'inchiesta fra le madri.

From a psychological point of view as well as in regard to facilitating breast-feeding, the practise of rooming-in is most favorable to the wellbeing of the mother-newborn relationship. An important but little researched point is whether the mother may accept rooming-in in respect to time periods, space and the manner in which it is carried out. The results of this study have made evident that time demand by the mother for contact between mother and newborn is inferior to that which is provided by the hospital, this is probably due to the lack of private space available.

Effects of continuous low-level exposure to radiofrequency radiation on intrauterine development in rats.

To assess the effect of low-level radiofrequency radiation on pregnant rats, gravid dams were exposed continuously to 0.1 mW cm-2 at 27.12 MHz during different periods of pregnancy. Biological assays consisted of determining pre- and post-implantation losses and the effects on maternal body weight increase. Fetal parameters monitored included sex, mean viable fetal weight on Day 20 of gestation, external, skeletal and visceral fetal malformations, anomalies and variations. Dosimetric evaluations were made in terms of average specific absorption rate (SAR) and basal metabolic rate (BMR). Findings included a considerable increase in the percentage of total resorptions, reduced body weight increase in the exposed dams and incomplete cranial ossification in their fetuses. Results obtained were compared with those shown by other authors. It seems possible to ascribe some of the effects to a specific action of the radiofrequency radiation occurring independently of the rise in temperature. The hypothesis the exposure time, together with SAR, plays an important role in inducing specific exposure effects due to radiofrequency radiation is presented.

Analysis of environmental pollution by radiofrequency radiation from teleradiocommunication devices.

The environmental radiofrequency radiation pollution, including microwaves, generated by teleradiocommunication devices is particularly great where there exists a concentration of such apparatus. The wide-band field detectors commonly used for environmental protection surveys do not make it possible to discern the contributions of the individual emitters at a given point. It is possible to obtain this result theoretically by using only a personal computer, and by using the characteristics of the emitter and of surrounding territory as inputs. For this purpose, a basic program has been prepared. An analysis of this type, besides being an effective tool for the planning of environmental pollution abatement, provides the necessary information for forecasting field levels produced as a consequence of the installation of new repeaters. This data provides indispensable information for issuing installation licenses by the competent authorities. This article concludes with a comparison between the theoretical results and those detected experimentally in one specific case.