Use of 2% taurolidine lock solution for treatment and prevention of catheter-related bloodstream infections in neonates: a feasibility study.

BACKGROUND: Taurolidine lock, a technique used to prevent or treat catheter-related bloodstream infection (CRBSI), is effective in adult and paediatric patients but has been described rarely in neonates. The aim of this descriptive retrospective study, was to determine the feasibility and direct outcomes of prophylactic and therapeutic taurolidine locks in term and preterm neonates. METHODS: We implemented the use of therapeutic taurolidine lock in addition to antibiotic treatment with the aim of catheter salvage in critical neonates with difficult vascular access (group 1). In addition, we introduced taurolidine lock as a preventive measure in neonates with a central venous catheter (CVC) at high risk of developing CRBSI (group 2). Every 24 h (in the treatment group) a 2% taurolidine solution was injected and the catheter locked for at least 120 min, until infection clearance (group 1). In the preventive group, the catheter was locked for 30 min every 48 h until CVC removal (group 2). FINDINGS: Thirty-seven neonates who received taurolidine were included in this study. We did not observe any major adverse events. In group 1 (21 cases), clinical symptom disappearance and bacteraemia clearance were achieved without catheter removal in 18 cases (85.7%); in the other three neonates the catheter was removed shortly after the start of the locks as it was possible to replace the CVC. In group 2 (16 neonates), no CRBSI was observed during the duration of the catheter placement. CONCLUSIONS: In this retrospective study, taurolidine was successfully used in neonates both for prevention and treatment of CRBSI, without major undesired effects. A larger cohort and a randomized clinical trial is warranted in order to establish its efficacy and safety in neonates.

EXPERIMENTAL VALIDATION OF ALGORITHMS USED TO ESTIMATE EFFECTIVE DOSE DURING INTERVENTIONAL RADIOLOGY PROCEDURES.

In IR procedures, in order to evaluate the effective dose, the importance of the double dosemeter has been recognised, one worn above and one under the apron. Over the last few decades several algorithms have been developed to combine the readings of the dosemeters, however currently there is no international consensus on which is the best one. In this work, eight irradiations, corresponding to typical interventional radiology procedures, were carried out in order to experimentally verify the accuracy of the algorithms. The patient was substituted by solid water-equivalent (RW3) layers, while effective dose to personnel was calculated by TLDs inside the Alderson Rando phantom. The results show that most of the algorithms, with a few exceptions, are too conservative, however there are many factors which can affect their accuracy, so it is impossible to achieve a high level of precision in the evaluation of the effective dose.

Topsoil radiological characterisation of L-54M reactor surroundings preliminary to decommissioning operations.

The radiological characterization of the topsoil of the L-54M reactor surroundings carried out in this work aims at obtaining the reference blank point for the forthcoming decommissioning operations and ascertain if unexpected radionuclide release occurred during the operational life of the plant. Standardised methods have been employed in order to collect representative samples and reliable results. Suitable sample pre-treatment procedures were applied. Gamma and beta spectrometric analyses were carried out to measure the activity concentrations of 60Co 137Cs, 152Eu, 241Am and 90Sr. These have been considered as representative radionuclides that could have been originated from reactor operations and that could still be present at four decades post reactor shutdown.

Design and test of a broadband split-and-delay unit for attosecond XUV-XUV pump-probe experiments.

We present the design of a split-and-delay unit for the production of two delayed replicas of an incident extreme ultraviolet (XUV) pulse. The device features a single grazing incidence reflection in combination with attenuation of remaining infrared light co-propagating with the XUV beam, offering a high throughput without the need of introducing additional optics that would further decrease the XUV flux. To achieve the required spatial and temporal stabilities, the device is controlled by two PID-controllers monitoring the delay and the beam pointing using an optical reference laser beam, making collimation of the beam by additional optics unnecessary. Finally, we demonstrate the stability of the split-and-delay unit by performing all-reflective autocorrelation measurements on broadband few-cycle laser pulses.

Tracing electron-ion recombination in nanoplasmas produced by extreme-ultraviolet irradiation of rare-gas clusters.

We investigate electron-ion recombination in nanoplasmas produced by the ionization of rare-gas clusters with intense femtosecond extreme-ultraviolet (XUV) pulses. The relaxation dynamics following XUV irradiation is studied using time-delayed 790-nm pulses, revealing the generation of a large number of excited atoms resulting from electron-ion recombination. In medium-sized Ar-Xe clusters, these atoms are preferentially created in the Xe core within 10 ps after the cluster ionization. The ionization of excited atoms serves as a sensitive probe for monitoring the cluster expansion dynamics up to the ns time scale.

Spontaneous thrombosis of the abdominal aorta in two neonates.

Although relatively rare, thromboembolic events are a major complication of invasive procedures, mainly vascular catheterization, required for the survival of neonates admitted to the neonatal intensive care unit. Sometimes symptoms may be ambiguous and the diagnosis may not be immediate. The clinical relevance of polymorphism of methilene tetrahydrofolate reductase (MTHFR) gene heterozigosity and of omocystein level in the genesis of these thromboembolic events are poorly understood. We report two cases of thrombosis of the abdominal aorta, mimicking aortic coarctation, in two neonates, successfully treated at diagnosis with 170 UI/Kg of low molecular weight heparin (LMWH) twice daily, without side effects. Screening for prothrombotic defects revealed the heterozygosity for MTHFR C677T in both neonates and low omocystein level in one of them. We suggest that in newborns vascular thrombosis should be considered in the differential diagnosis of acute disorders of blood circulation at birth and familial thrombophilia should be investigated. LMWH therapy with a dose of 170 UI/Kg twice daily usually allows vascular recanalization, without side effects.

Administering 25-hydroxyvitamin D3 in vitamin D-deficient young type 1A diabetic patients reduces reactivity against islet autoantigens.

BACKGROUND & AIMS: We investigated whether improving 25-hydroxyvitamin D status in young type 1A diabetic patients reduces reactivity of peripheral blood mononuclear cells against islet autoantigens and associates with beta-cell functional changes. METHODS: Eight patients with 25-hydroxyvitamin D deficiency (<20 ng/ml), out of 15 consecutive young type 1A diabetic subjects received 25-hydroxyvitamin D3 to achieve and maintain levels above 50 ng/ml for up to one year. Peripheral blood mononuclear cell reactivity (Interferon-γ spots) against beta-cell autoantigens (glutamic acid decarboxylase 65-kD isoform, proinsulin and tyrosine phosphatase-like protein IA-2) and C-peptide during mixed meal were assessed before and after 25-hydroxyvitamin D3 replenishment. RESULTS: Target 25-hydroxyvitamin D blood levels were safely reached and maintained. Peripheral blood mononuclear cell reactivity against glutamic acid decarboxylase 65-kD isoform (3.8 ± 4.0 vs. 45 ± 16) and proinsulin (3.5 ± 3.2 vs. 75 ± 51) decreased significantly (p < 0.001 and p < 0.02) upon 25-hydroxyvitamin D3 replenishment, which was correlated with 25-hydroxyvitamin D concentrations. C-peptide values remained stable after one year of treatment. CONCLUSIONS: Safely restored and maintained 25-hydroxyvitamin D levels associated with reduced peripheral blood mononuclear cell reactivity against beta-cell autoantigens with no significant decrease of beta-cell function in this cohort of patients.

Optimal positioning of the humeral component in the reverse shoulder prosthesis.

INTRODUCTION: Total reverse shoulder arthroplasty is becoming more and more the standard therapeutic practice for glenohumeral arthropathy with massive lesions of the rotator cuff. The biomechanical principle of this prosthesis is represented by the reversion of the normal anatomy of the shoulder joint. This non-anatomical prosthesis leads to a medialization of the rotation centre of the glenohumeral joint and also to a distalization of the humeral head. All that causes a deltoid tension increasing so allowing a larger abduction of the arm. Main complications of the reverse shoulder prosthesis are due to the joint instability, the scapular notching and the wear of the polyethylene insert. PURPOSE: The main goal of the present work is to study the effect of the positioning of the humeral component on the intrinsic stability of the reverse shoulder prosthesis. In particular, through finite element method simulations, the variation of the stability ratio of the shoulder joint has been calculated for both vertical and horizontal dislocating loads depending on the humeral stem version angle. Moreover, in order to estimate the wear of the polyethylene cup, some analyses have been developed to calculate the pressures on the polyethylene insert. RESULTS: The obtained results demonstrate the dislocation of a shoulder prosthesis and the wear of the polyethylene insert can be prevented or limited by conveniently varying the version angle of the humeral component.

Methods for dose measurements in small phantoms irradiated at BNCT epithermal column.

Suitable dosimeter methods have been proposed and tested, to measure the different dose contributions in small phantoms exposed to epithermal/thermal neutron beams designed for BNCT. One method is based on Fricke-gel dosimeter in small tubes of 2.8mm of external diameter, that allow determining profiles of gamma dose and of boron dose. The other method is based on the use of TLD-700 chips, from whose answer the contribution of thermal neutrons is subtracted by means of appropriate parameters of the glow curve.

A high-flux high-order harmonic source.

We develop and implement an experimental strategy for the generation of high-energy high-order harmonics (HHG) in gases for studies of nonlinear processes in the soft x-ray region. We generate high-order harmonics by focusing a high energy Ti:Sapphire laser into a gas cell filled with argon or neon. The energy per pulse is optimized by an automated control of the multiple parameters that influence the generation process. This optimization procedure allows us to obtain energies per pulse and harmonic order as high as 200 nJ in argon and 20 nJ in neon, with good spatial properties, using a loose focusing geometry (f#≈400) and a 20 mm long medium. We also theoretically examine the macroscopic conditions for absorption-limited conversion efficiency and optimization of the HHG pulse energy for high-energy laser systems.

Treatment of clavicle fractures.

Clavicle fractures are very common injuries in adults (2-5%) and children (10-15%) (1) and represent the 44-66% of all shoulder fractures (2). Despite the high frequency the choice of proper treatment is still a challenge for the orthopedic surgeon. With this review we wants to focus the attention on the basic epidemiology, anatomy, classification, evaluation and management of surgical treatments in relationship with the gravity of injuries. Both conservative and surgical management are possible, and surgeons must choose the most appropriate management modality according to the biologic age, functional demands, and type of lesion. We performed a review of the English literature thought PubMed to produce an evidence-based review of current concept and management of clavicle fracture. We finished taking a comparison with our survey in order to underline our direct experience.

Multichannel computed tomography (MCCT) analysis of glenoid erosion in shoulder hemiarthroplasty: preliminary clinical applications.

Glenoid wear following shoulder hemiarthroplasty (HA) has been reported around 80% in long-term follow-up studies. Radiographic analysis is useful to depict glenoid erosion but does not evaluate accurately glenoid bone loss. Multichannel computed tomography (MCCT) allows scanning with submillimeter section thickness through dense areas of glenoid bone, despite the presence of metallic prostheses. In this preliminary study, we performed a MCCT analysis of glenoid erosion, in 15 patients with painful shoulder HA, at an average follow-up of 5.5 years. Clinical scores were retrospectively assessed at an early (1 year), medium (2.5 years), and late (5.5 years) follow-up. We analyzed the following glenoid features: articular line space (ALS), glenoid length (bone stock), glenoid version, morphology of erosion (concentric, superior ed inferior tilt), and gross bone defects. Glenoid was retroversed in 13 patients (minimum 0 degrees maximum 8 degrees), antiversed in 2 patients (2 degrees and 6 degrees). Erosion was described as concentric in 13 patients, eccentric ("superior tilt") in 1 patient, biconcave in another patient. The mean glenoid length was 19.7 mm (min 16.4 max 22.7). Gross bone defects were described in six patients. The scores registered at latest follow-up showed a significant decrease compared with the values at 1 year (P < 0.001) and at 2.5 years (P < 0.001). The patients with glenoid erosion associated with gross defects and ALS

Surgical approach to acute pectoralis major tendon rupture.

Pectoralis major rupture is a very uncommon injury first time described by Patissier in 1822. Tears are classified on the type (partial and complete) or on the site (tendinous, myotendinous junction, intramuscular). Ruptures are reported in young high-performance athletes as results of eccentric contractions of the musculotendinous unit. The most probable mechanism in elderly patients is a brisk tearing movement applied to stiff atrophic muscle. Injuries generally involve the sternal portion; the localization to the clavicular portion is rare and can be misdiagnosed as muscle sprain. Preoperative planning include MRI as gold standard regarding operative versus non operative treatment decisions. Surgical repair is recommended in cases of complete tears because of loss of strenght in adduction, flexion and internal rotation. Aim of the current study is to describe the surgical repair of acute pectoralis major tendon rupture in 5 patients. Surgery was performed through a modified delto-pectoral approach; pectoralis major tendon was attached at its anatomic insertion using two metallic anchors. The patient as been immobilized in a sling for 30 days and then assisted physiotherapy begun; strenght exercises were allowed at 90 days. At a mean follow-up of 24 months results were excellent in all cases with restoration of strenght and coming back to previously sports activity.

Endoscopic approach to cubital tunnel syndrome.

The cubital tunnel syndrome is one of the most common entrapment neuropathy of the upper limb. The ulnar nerve can be compressed in the oteofibrous tunnel by the bone structures, the Osborne's ligament, the fascia of the ulnar flexor muscle of the carpus or of the aponeurosis of the deep flexor of the fingers. Pressure values in the cubital tunnel >50 mm Hg induce blocking of intraneural circulation with electrodiagnostic modifications, clinical signs and histological changes including demyelinazion of the nerve proximal to the cubital tunnel. Surgery becomes essential in case of failure of conservative and physical therapy. Various surgical techniques have been described in the literature for the treatment of the ulnar neuropathy at the elbow. In this paper the authors report a new endoscopic technique for the treatment of ulnar nerve entrapment at the elbow which requires respect of specific electrodiagnostic and clinical criteria of inclusion. The restored joint active motion following elbow arthroscopy in osteoarthritis can induce or get worse a ulnar nerve neuropathy; endoscopy neurolysis is essential to remove perineural adherences and reduces the nerve stress. Immediate well-being of the patient, lesser invasiveness and minimum vascular complications are clear advantages of the endoscopic approach, while the treatment of the pathologies proximal and distal to the Struther's arcade is a limit of the technique.

Sensitivity study of CR39 track detector in an extended range Bonner sphere spectrometer.

Bonner sphere spectrometers (BSS) are being used widely in neutron spectrometry since 1960. The response to neutrons of these moderating detectors spans over a broad energy range. This work discusses the measurement of the sensitivity of an extended range BSS hosting a CR39 nuclear track detector coupled to a boron converter. Two kinds of boron converters were tested, the first made by natural boron and a second one enriched in (10)B. The BSS response functions were calculated with Monte Carlo simulation using the MCNPX 2.4.0. and the FLUKA codes.

Beam dumps design and local radiation protection at TERA synchrotron.

The realisation of the National Center of Hadrontherapy was funded by the Italian Government in 2002. The Centre will be built in the area of Pavia (Italy). The synchrotron designed in the framework of this programme will accelerate protons and carbon ions up to 250 MeV and 400 MeV u(-1), respectively. Some of the main aspects which were taken into account in the design of the acceleration system are the patient's safety and the beam control. From this point of view an important role is played by the beam dumps in the synchrotron ring and upstream of the extraction system. In particular, an horizontal and a vertical beam dump will be installed in the synchrotron ring: the former will be used for lowering the beam intensity and the latter for beam abortion. The dump at the extraction will absorb the particles during the mounting and the falling ramps of the synchrotron magnetic cycle, thus extracting only the flat top of the ion spill. Beam dumps can produce intense fields of secondary radiation (neutrons, charged light-hadrons and photons) and high rates of induced activity, since they can absorb the beam completely. Usually they have to be shielded to protect the electronics during machine operation and to attenuate the radiation dose below the limits imposed by the law when the personnel access to the synchrotron hall. The part of the shielding design of the beam dumps concerning with the acceleration of protons was made using Monte Carlo simulations with the FLUKA code. Both induced activity and secondary radiation were taken into account. The shields against secondary radiation produced by carbon ions were designed, referring only to secondary neutrons, taking double-differential distributions from the literature as sources for the FLUKA simulations. The induced activity from carbon ions interactions was estimated analytically, using the data generated by the EPAX 2 code. The dose-equivalent rates from the induced radionuclides were calculated at 1 m from the shielded dumps, taking into account the contribution of activated components of the synchrotron ring.

Evaluation of etching correction factor for LR115 cellulose nitrate films from track parameters.

LR115 cellulose nitrate films efficiency is strongly dependent on the conditions of etching. In this paper a new method to evaluate a correction factor for this effect is given. The film is scanned with an high-resolution scanner, the diameter of the tracks is measured, and the correction factor is calculated from the average diameter of the tracks. The sensitivity of the film is found to have a linear dependence on the average diameter, and the classical correction, based on the residual thickness, can be substituted by a method based on average track diameter.