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.

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.

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.

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.

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 <or=1.2 mm had lower scores for pain and lower scores for ROM (P < 0.01). Multidetector CT analysis establishes a new frontier in the postoperative management of shoulder arthroplasty, and its application in the glenoid analysis offers a significant contribution for the following reasons: qualitative and quantitative glenoid features are better seen because volume-rendering eliminates most streak artifacts and produces high-quality images; spatial information relative to the prosthetic devices and the relationship among hardware and bone can be better demonstrated; allows an accurate preoperative planning prior to starting with revision surgery.

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.

The Bristow-Latarjet method in the treatment of shoulder instability that cannot be resolved by arthroscopy. A review of the literature and technical-surgical aspects

Arthroscopy has surpassed traditional types of open surgery in the treatment of shoulder instability because of its mini-invasiveness and shorter rehabilitation time. Despite this, in some cases, such as those involving significant glenoid erosions and extensive capsular lesions, arthroscopic methods fail the objectives, and methods that were believed to have been surpassed are again used, such as the Bristow-Laterjet procedure. It is the purpose of this article to describe use of the method in light of the possibilities offered by arthroscopy.

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.

Arthroscopic neurolysis of the ulnar nerve at the elbow

Cubital tunnel syndrome is a frequent form of neuropathy caused by entrapment of the upper limb. Conservative treatment and physical therapy are the treatment of choice for at least 6 months prior to any type of surgery. The surgical techniques proposed for treatment of this syndrome include simple decompression, transposition and neurolysis. It is the purpose of this study to demonstrate the advantages of arthroscopy for neurolysis of the ulnar nerve at the elbow in a specific cohort of patients. The patients were evaluated preoperatively and postoperatively based on subjective (VAS) and objective (Bishop and Dellon) scales. The degree of patient satisfaction on the average was more than 60%. The mean increase in Bishop score was 5 points (minimum 3, maximum 7). Results appeared to be good and stable at 6 and 12-month follow-up evaluation.

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.

Comparison between arthroscopy and arthrotomy in the treatment of shoulder instability

Anterior post-traumatic shoulder instability represents a common finding in orthopaedic surgery. The surgical treatment of this lesion is often indispensable for the normal social life of the patient and for the sports activity of the young. The Bankart procedure with capsular retensioning by arthrotomic access has for years been the gold standard. In the last 10 years arthroscopic accesses have gained more and more consent for the surgical treatment of such lesions, with results that have considerably improved in time. It is the purpose of this study to compare the results obtained in patients affected with anterior-inferior post-traumatic shoulder instability treated by Bankart surgery, arthrotomic and arthroscopic, with a minimum follow-up of 4 years.

Uncertainties evaluation for electrets based devices used in radon detection

In recent years uncertainty evaluation in measurements has achieved great importance. National and international standards offer guidelines to evaluate uncertainties, but these procedures are, until now, not well understood by the operators. This is because of the fact that a detailed uncertainty evaluation is not an easy operation and a standard rule to apply in all cases is not available. Every measurement procedure has its own uncertainty evaluation. In this work, attention is focused upon the electret ion chambers (EIC), widely used in radon concentration measurements. Measurements of gamma radiation sensitivity are performed in a secondary standard calibration laboratory and measurement of radon concentration sensitivity is performed in a radon chamber 0.8 m3 in volume. Raw data are analysed to evaluate the calibration factors and the combined uncertainties are determined. The aim of the work is to give a practical method to assess the uncertainty of a radon measurement.

Uncertainty evaluation of radon measurements with LR115 detector and spark counter

To evaluate the uncertainties for nuclear track detectors used in radon measurements, a full understanding is required of the physical phenomena involved and the behaviour of the instruments utilised in the measuring process. As it concerns the LR115 nuclear track detector, an overall evaluation of uncertainty was given. It was assessed taking into account different contributions and determining their relative weights. Since such detectors are often read by a spark counter device, a model to describe its behaviour was developed and a saturation factor was estimated. Its expression and its associated uncertainty are given. Hence, it has been possible to draw a calibration curve, in which all the uncertainty sources have been considered.

Non-invasive measurement of water content in lung phantom by neutrons: latest improvements to the technique

The novel technique for measuring the water content in lungs based on the slowing down of fast neutrons has been improved making possible its clinical use on patients. This goal has been reached by performing computer simulations that closely mimic the experimental setup and by acquiring a new set of measurements obtained with a plutonium-beryllium (Pu-Be) neutron source provided of an activity suitable to clinical requirements. Finally, accurate radiation dose measurements have been carried out to ensure the acceptability of the technique.

Technical procedures for the evaluation of different radiation detection systems at the entrance of a waste incinerator plant

To protect a new waste incinerator plant and the population against the accidental introduction of radioactive material in the furnace, in 1998 the Municipal Service Corporation of the city of Brescia decided to acquire a radiation detection portal system. However, the performance of such instruments is not sufficiently specified in this type of application, so ASM asked the Nuclear Engineering Department of the Polytechnic of Milan to draw up a test protocol and to lead the following experimental campaign. A truck trailer and a source container were prepared ad hoc, and three different systems underwent a sensitivity and a false alarm test. On the basis of the final results, the performance characteristics of various monitoring systems in this particular application were established with the correct degree of accuracy.

Complex traumatic-degenerative injury of the proximal metaepiphysis of the humerus

The authors describe one case of displaced fracture of the proximal third of the humerus with high-grade degenerative arthropathy in the humeral head and in the glenoid surface on a humerus that had previously been treated thirty years earlier with a Delitala intramedullary nail for diaphyseal fracture.

Thermodynamically distinct high and low affinity states of the A(1) adenosine receptor induced by G protein coupling and guanine nucleotide ligation states of G proteins

The influence of the receptor-G protein coupling state and the guanine nucleotide ligation state of the G protein on the binding mechanism of A(1) adenosine receptor ligands has been investigated in [(3)H]-1,3-dipropyl-8-cyclopentylxanthine ([(3)H]-DPCPX) binding studies in rat brain membranes. Thermodynamic parameters of binding of A(1) adenosine receptor ligands of different intrinsic activities were determined in the absence or presence of GDP and compared to the binding mechanism after receptor-G protein uncoupling. In agreement with previous studies, it was found that xanthine and non-xanthine antagonists showed an enthalpy- or enthalpy- and entropy-driven binding mechanism under all conditions. In contrast to antagonists, the binding mechanism of agonists was strongly affected by the G protein coupling state or the absence or presence of guanine nucleotides. Binding of full and partial agonists to the high-affinity state of the A(1) receptor was entropy-driven in the absence of GDP, and a good correlation between intrinsic activities and the contribution of entropy was observed. In the absence of GDP, binding of full and partial agonists and antagonists to the high affinity state of the receptor was thermodynamically discriminated. In contrast, no such discrimination was found in the presence of GDP. The binding mechanism of agonists to the low-affinity state of the receptor was identical to that of antagonists only after uncoupling of the receptor from G proteins by pretreatment with N-ethylmaleimide or guanosine-5'-(gamma-thio)-triphosphate (GTPgammaS). These results indicate the existence of two thermodynamically distinct high- and low-affinity states of the A(1) adenosine receptor.

Non-invasive measurement of water content in a lung phantom by neutrons

A novel, non-invasive technique for measuring water content in lungs is described. This technique could find important medical applications such as real time monitoring of lung edema development in patients affected by cardiac insufficiency undergoing physical effort. The technique is based on the moderation (speed decrease) of fast neutrons crossing the lungs, due mostly to the water contained in lungs. In the application of this diagnostic method, the necessary dose given to the patient is lower than that associated with lung imaging techniques that do not use an image intensifier. The results so far obtained are encouraging, and the method appears to be an improvement over those so far reported in literature as it is able to detect a lung water increase equivalent to 25% of a full edema with a 20% standard error. Research is being performed in order to refine the technique, investigate geometry effects and make the method suitable to the medical field.

Endocrine-disrupting agents on healthy human tissues

A vast number of substances have been suggested as possibly contributing to perturbation of the endocrine system. Several have been tested with different approaches ranging from yeast expression system of human oestrogenic receptors to human breast cancer cells assays. Surprisingly, no inhibition-binding experiments to steroid receptors on healthy human tissue have been performed so far. Our study provides inhibition binding experiments to oestrogens, progesterone, testosterone and retinoic acid receptors in prostate and uterine human tissue of organochlorine pesticides, phthalate esters, oestrogenic constituents derived from plants and phenol derivates. Affinities of significant extent of phthalates on oestrogenic, progestinic and androgenic receptors have not been detected. As for retinoic acid receptors, mono(2-ethylexyl)phthalate provokes a notable reduction of the binding of the tritiated retinoic acid, phtalic acid ethyl-n-butyl ester and 4-octylphenol show an affinity comparable to that of isoflavonoid genistein, whereas 4-nonylphenol reduces the binding of retinoic acid in prostate.

Early changes in adenosine A1 receptors in cerebral cortex slices submitted to in vitro ischemia

The effects of brain ischemia on the maximum binding capacity (Bmax) and affinity (Kd) of A1 receptors were studied in the rat cerebral cortex, with an in vitro approach. The results were correlated with changes in 3H-adenosine release, studied under identical experimental conditions. Fifteen minutes of in vitro 'ischemia' (hypoxic, glucose-free medium) induced a significant increase in both Bmax (2398+/-132 fmol/mg protein, 151% of the control, P < 0.05) and in Kd (2.43+/-0.12 nM, 161% of the control, P < 0.01). At the same time, an increase in tritium efflux from [3H]-adenosine labeled cerebral cortex slices to 324% of the control was observed. A trend toward normalization was evident 5-15 min after 'reoxygenation' (restoring normal medium), but the binding parameters were still altered after 60 min (Bmax 2110+/-82 fmol/mg protein, Kd 2.26+/-0.14 nM, P < 0.01 vs the corresponding control) as was adenosine release (196% of the control). These findings suggest that the increased availability of adenosine and its receptors may be a defense mechanism against ischemic injury, while the reduced affinity of A1 receptors, possibly due to desensitization, may be a sign of ischemia-induced cellular damage.

Alpha2-adrenergic agonist modulation of [35S]GTPgammaS binding to guanine-nucleotide-binding-proteins in human platelet membranes

Alpha2-adrenoceptor (alpha2-AR)-regulated binding of the labelled GTP analog, guanosine 5'-O-(3-[35S]thiotriphosphate) ([35S]GTPgammaS), to guanine-nucleotide-binding proteins (G proteins) was studied in human platelet membranes. Under optimal conditions, the potent alpha2-AR agonist, 5-bromo-6-(2-imidazolin-2-ylamino)-quinoxaline (UK 14304), increased the binding of [35S]GTPgammaS up to approximately 1.8 fold, with half-maximal increase at 60 nM and was competitively inhibited by the alpha2-AR antagonist Rauwolscine. The actions of both UK 14304 and Rauwolscine were modulated by monovalent and divalent cation levels, as well as by the concentrations of GDP. [35S]GTPgammaS binding induced by UK 14304 had a Kd value of 4.5 +/- 0.3 nM and a Bmax value of 4.15 +/- 0.40 pmol/mg protein. The rank order of potencies of adrenergic ligands tested in stimulating [3S]GTPgammaS binding and inhibiting forskolin-stimulated c-AMP accumulation was UK 14304> Guanabenz acetate> Oxymetazoline hydrochloride> B-HT 920 dihydrochloride> p-Aminoclonidine hydrochloride> Clonidine hydrochloride. The data presented indicate that enhancement of [35S]GTPgammaS binding by alpha2-AR in human platelet membranes provides a simple functional measure for receptor activation and can be used for determination of potencies and efficacies of ligands at the alpha2-AR.

Hardness of plantar skin in diabetic neuropathic feet

To evaluate if skin hardness in diabetic neuropathic feet was increased and if its eventual modifications could be correlated to the severity of neuropathy, we studied a group of diabetic outpatients with and without neuropathy. Patients, selected among those who were attending their routine screening for diabetic neuropathy at our diabetologic clinic, were divided into two groups according to the presence (ND+) or absence (ND-) of diabetic neuropathy with the criteria of the S. Antonio Consensus Conference on Diabetic Neuropathy. Patients then underwent an evaluation of vibration perception threshold (VPT) by means of a biotesiometer, measurement of skin hardness (DMT) by means of a durometer, and transcutaneous oxygen tension (TcPO2) determination. VPT was determined at allux (VPT-A) and external malleolus (VPT-M), DMT was measured at heel (DMT-H), at medial (DMT-M) and lateral (DMT-L) midfoot, and at posterior midcalf (DTM-C) as a control site; TcPO2 was evaluated at dorsum (TcPO2-D) and at medial midfoot (TcPO2-M), respectively. All measurements were performed on the nondominant side with the patients supine. Patients were compared with age and gender-matched healthy volunteers (Controls), who underwent the same evaluations in the same order. ND+ patients showed higher values of VPT than ND- and Controls, both at first toe and at malleolus analysis of variance (ANOVA) p<0.01), as well of DMT in all the three sites explored (ANOVA, p<0.01). Moreover, ND+ showed no difference in DMT among the sites, while both in ND- and in controls DMT-M was significantly (p<0.05) lower than DMT-H and DMT-L. No difference among the three groups were observed in TcPO2 measurements, and no difference in DMT-C was observed either. A significant correlation was observed between DMT-H and VPT-M (r2 = 0.516) and between DMT-M and VPT-A (r2 = 0.624) in ND+ patients. Skin hardness was diffusely increased in ND+ patients, and this increase strongly correlates with the severity of neuropathy. Simple, noninvasive determination of skin hardness could identify patient at potential risk to develop neuropathic foot ulcers.

Hemiarthroplasty of the shoulder. Clinical experience in 18 cases treated by the Neer monoblock prosthesis

The authors report the results of 18 hemiarthroplasties of the shoulder performed between 1990 and 1994 using the Neer II monoblock prosthesis, emphasizing the technical and surgical problems encountered. The patients treated numbered 13 for traumatic pathology (acute fractures: 7; sequelae of fracture of the proximal epiphysis of the humerus: 6), and 5 for degenerative lesions (arthrosis: 3; rheumatoid arthritis: 2). An evaluation of the results was based on the Constant method and isokinetic testing. Results based on follow-up obtained after 2 to 6 years were satisfactory in 83% of the cases.

A method and apparatus for monitoring the level of tritiated water vapor in air using a solid scintillator

Tritium is presently used in large quantities in laboratories for technological studies, as fuel for the process of nuclear fusion, and in the manufacture of radio-luminescent items. It is also produced in fission nuclear plants (with a yield of 10(-4) if the fuel is 235U and twice as much if the fuel is 239Pu), particularly in those which use D2O as moderator. The weak energy of beta particles (Emean=5.7 keV) produced by tritium implies that it is only harmful if internalized. In nature tritium in air is mainly present under two different chemical forms: elementary (HT, DT, T2) and oxidized (HTO, DTO, T2O). The latter is extremely more dangerous than the former as far as radioprotection is concerned; for this reason the derived air concentration limit (8 x 10(5) Bq m(-3)) for the gaseous form is 25,000 times higher than the value for the oxidized one. The purpose of the work presented here is to realize an area monitor that is able to discriminate in real time between the two chemical forms. Using the properties of zeolite as an absorber and scintillator, it was possible to construct such a detector. In 1 h the instrument can reveal HTO concentrations 40 times below the derived air concentration. A concentration equal to the derived air concentration can be revealed within the first minute of counting and the performance may be further improved. Moreover, the prototype realized is able to work automatically and continuously for 5 h. The capability of discriminating the oxidized chemical form, the sensitivity, and the possibility of obtaining real time information make this instrument a good monitor in those cases where there is a real risk of tritium air contamination.

Conservative surgical approach versus non-surgical management for diabetic neuropathic foot ulcers: a randomized trial

To test the efficacy of surgical treatment of non-infected neuropathic foot ulcers compared to conventional non-surgical management, a group of diabetic outpatients attending our diabetic foot clinic were studied. All patients who came to the clinic for the first time from January to December 1995 inclusive with an uncomplicated neuropathic ulcer were randomized into two groups. Group A received conservative treatment, consisting of relief of weight-bearing, regular dressings; group B underwent surgical excision, eventual debridement or removal of bone segments underlying the lesion and surgical closure. Healing rate, healing time, prevalence of infection, relapse during a 6-month period following intervention and subjective discomfort were assessed. Twenty-four ulcers in 21 patients were treated in group A (17 Type 2 DM/3 Type 1 DM, age 63.24 +/- 13.46 yr, duration of diabetes 18.2 +/- 8.41 yr, HbA1c 9.5 +/- 3.8%) and 22 ulcers in 21 patients in group B (19 Type 2 DM/2 Type 1 DM, age 65.53 +/- 9.87yr, duration of diabetes 16.84 +/- 10.61 yr; HbA1c 8.9 +/- 2.2%). Healing rate was lower (79.2% = 19/24 ulcers) in group A than in group B (95.5% = 21/22 ulcers; p < 0.05), and healing time was longer (128.9 +/- 86.60 days vs 46.73 +/- 38.94 days; p < 0.001). Infective complications occurred significantly more often in group A patients (3/24, 12.5% vs 1/22, 4.5%; p < 0.05), as did relapses of ulcerations (8 vs 3; p < 0.01). There were only two minor perioperative complications in group B patients. Patients reported a higher degree of satisfaction in group B (p < 0.01) as well as lower discomfort (p < 0.05) and restrictions (p < 0.05). Thus surgical treatment of neuropathic foot ulcers in diabetic patients proved to be an effective approach compared to conventional treatment in terms of healing time, complications, and relapses, and can be safely performed in an outpatient setting.

Inhibition of endosomal acidification in normal cells mimics the derangements of cellular insulin and insulin-receptor metabolism observed in non-insulin-dependent diabetes mellitus

Dissociation of the insulin-insulin receptor complex plays a crucial role in the processing of both insulin and the insulin receptor, and the acidification of endocytic vesicles may be the mechanism by which internalized insulin is dissociated from its receptor and properly sorted and processed. Internalized insulin-insulin receptor complexes are abnormally processed in cells from patients with non-insulin-dependent diabetes mellitus (NIDDM). Accordingly, to further investigate the mechanisms of the derangements observed in NIDDM cells, we examined the effects of the ionophore monensin, which inhibits endosomal acidification, on the cellular processing of insulin and insulin receptor in monocytes from control subjects (n = 12) and NIDDM patients (n = 14). This study confirms that monocytes from NIDDM patients, compared with cells from normal controls, had reduced binding (P < .01), internalization (P < .01), and degradation (P < .01) of insulin. In addition, the release of intracellular radioactivity was slower (P < .01), and recycling of the insulin receptor was inhibited (P < .01). Moreover, these defects were associated with a significant (P < .01) decrease of dissociation of the internalized insulin-insulin receptor complex. In cells from normal controls, incubation with monensin decreased insulin binding (P < .01), but not insulin internalization. High-performance liquid chromatography (HPLC) analysis of intracellular radioactivity showed that after monensin intracellular intact insulin significantly increased (P < .01), thus suggesting a decrease of intracellular insulin degradation. Moreover, insulin receptor recycling was completely disrupted. All of these derangements were associated with a significant decrease (P < .01) of dissociation of insulin-insulin receptor complexes. On the contrary, in diabetic monocytes, monensin had no significant additional effect on NIDDM-linked alterations. Comparison of the results obtained in cells from NIDDM patients to those found in monensin-treated normal cells demonstrates that NIDDM and monensin gave rise to a superimposable impairment of dissociation of the intracellular insulin-insulin receptor complex, associated with similar abnormal sorting and processing of insulin and its receptor. The only defect present in NIDDM cells but not in monensin-treated cells is the decrease of insulin internalization, which thus seems independent of the action of monensin on the processing of internalized insulin-insulin receptor complex. These results suggest that the impairment of dissociation of the insulin-insulin receptor complex may play a crucial role in the subsequent altered processing of insulin and insulin receptor. Moreover, they raise the question as to a possible similar alteration of the same intracellular mechanism by NIDDM and monensin, and point out that the derangements found in cells from NIDDM patients could be localized within the endosomal apparatus and consist mainly of a defective acidification of its interior.

Diabetologic in-service education for health professionals from non-diabetological departments

In order to test whether or not an in-service requalification course on diabetes care for health professionals (HP) of nondiabetological departments can enhance their level of knowledge about diabetes and the quality of care for diabetic inpatients admitted for reasons other than diabetes, we carried out a requalification course involving 171 HP (161 nurses and 10 midwives) from nondiabetological departments of our hospital. Areas of intervention were: general knowledge of diabetes (GKD), bedside monitoring of blood glucose (BMG), insulin preparation and administration (IPA), diagnosis and treatment of hypoglycemic crises (DTH), and hospitalization-related problems (HRP). HP, divided into groups of about 20 each, completed a basal evaluation by means of a 25-item multiple choice questionnaire, and then attended six separate educative sessions, each of focusing on one topic, consisting of a theory lesson and an interactive exercise of equivalent length. At the end of the course, HP were re-evaluated with the same questionnaire, and their skills in BMG, IPA and DTH were tested by means of specific operational checklists, which divided each complex operation into a sequence of single operations, and then compared them with those of a control group of untrained colleagues (CG). The global knowledge of diabetes after the courses significantly improved, as gathered from the percentages of correct answers in each questionnaire (61.82% +/- 23.64% vs 31.18% +/- 20.00%; P < 0.001); separate analysis of different areas evidenced improvements in GKD (72.28% +/- 12.47% vs 31.46% +/- 20.56%; P < 0.01), BMG (68.77% +/- 15.75% vs 37.50% +/- 27.75%; P < 0.01), IPA (72.02% +/- 11.72% vs 33.45% +/- 21.22%; P < 0.05), and DTH (90.76% +/- 6.86% vs 49.82% +/- 26.68%; P < 0.05), but not in HRP. Professional skills profiles of HP, evaluated by measuring the number of errors done performing each task, were significantly (P < 0.001) better than those of CG, for BMG (1.09 +/- 0.73 vs 4.91 +/- 2.01), IPA (2.36 +/- 1.64 vs 5.64 +/- 2.25), and DHT (1.27 +/- 0.94 vs 3.82 +/- 1.12). Linear regression showed a significant (P < 0.001) correlation of skills and knowledge after the course for BMG (r2 = .49), IPA (r2 = .53), and DTH (r2 = .61). Positive although nonspecific indicators of outcomes of the course were the increase (of about 100%) of requests to our metabolic unit for diabetological consultations from other departments as well as the mentioning of diabetes in the diagnosis of discharge, and the 20% increase in the consumption of sticks for BMG. The course produced a significant improvement of knowledge and skills on specific diabetological items among participants.

A gas scintillation monitor for tritium gas in argon or in nitrogen

For civilian purposes tritium is presently used in quantities of tens of PBq (MCi) in laboratories for the studies of tritium technology, at the Joint European Torus plant (Abingdon, Oxon, OX143A, UK) as fuel for the process of nuclear fusion, and in the manufacture of radio-luminescent items. Given the extreme mobility of tritium in most materials, it is necessary to use systems for double containment, such as glove boxes or spaces between primary and secondary containers, in which inert gas like argon or nitrogen flows. With these systems it is possible to recover tritium that escapes from the primary containment. Presently the gas flow is monitored continuously by means of ionization chambers which may present problems in particular applications ("memory effect" with high activity, strong dependence of the response on the presence of impurity, etc.). The aim of the work here presented is to determine the prospects for the realization of a new type of monitor mainly dedicated to the measurement of gas activity in isolation space of the containing systems of the high activity tritium plants. This monitor should have sufficient sensitivity, quick response, and should be easily decontaminated. As a detection technique we chose the scintillation produced in the inert gas by radioactive decay. With the first prototype, designed in cylindrical form, it was possible to observe gaseous scintillation events in mixture of tritium and argon or nitrogen. Following that, a spherical prototype was designed, of which we studied the performances and the dependence of the response varying the pressure, the concentration of tritium, the percentage of the impurity, and the gas flow rate. The results are satisfactory and suggest that the monitor could be used in glove boxes and double containment systems. The future research program will include tests involving large quantities of tritium and a study of the ideal dimensions and geometry of the detection chamber in order to optimize the detector response.

Isokinetic testing to evaluate patients submitted to surgery for the treatment of surgical lesion of the rotator cuff

A total of 100 cases surgically treated for rupture of the extra-rotator cuff were evaluated by isokinetic testing. Results were evaluated after a period of time ranging from 1 to 4 years, based on the Constant system, defining the type of lesion of the cuff based on the Snyder classification system, and measuring strength postsurgery using isokinetic testing after 3 and 6 months, and 1 year. Isokinetic testing made it possible to accurately evaluate which patients are capable of obtaining better recovery, and how much time is required for physiotherapy for postoperative rehabilitation, also allowing for correction on an individual basis of any muscular imbalance.

Calcific tendinitis of the rotator cuff with trochiteal osteolysis. A rare clinical radiologic complication

Among cases of calcific tendinitis that are unresponsive to any type of non-surgical treatment, the authors report 3 cases, out of a total of 32 submitted to surgery, that presented with an osteolytic cavity filled with calcium salts in the insertional region of the supraspinous tendon. These patients presented with pain that they had been experiencing for an average of 4 years, with acute recurrent episodes. When this pathology can be determined radiographically, early surgery is recommended, considering that any type of non-surgical treatment is destined to fail.

[Rotator cuff rupture in the shoulder impingement syndrome. Echography and arthrography: 2 diagnostic methods compared]

After briefly reviewing the shoulder impingement syndrome, the authors investigate the role of two diagnostic imaging methods, i.e., ultrasonography (US) and arthrography, in demonstrating the typical features of this condition. Over a 15 months' period, 190 patients suffering from shoulder pain were examined with arthrography; 50 of them subsequently underwent acromion plastic surgery and rotator cuff stitching. This study was aimed at comparing US and arthrographic results, applying classifiable criteria to make the most accurate diagnosis of rotator cuff tears. The lack of visibility of the rotator cuff at US was the major and clearest sign of tear (100% of cases). The association between cuff thinning and hypo/hyperechoic damaged focal areas was another major sign (in 76.19% of complete tears and in 14.28% of incomplete tears). Hyperechoic focal areas alone proved to be a false-positive finding in 5 cases, while in 11 of 19 cases normal US patterns were a false-negative finding; in 3 cases other conditions were diagnosed. To conclude, the value of US is emphasized in the screening of the painful shoulder and the use of arthrography is suggested when both clinical tests and US fail to yield enough information for a diagnosis to be made.

Tears of the rotator cuff associated with neurologic disorders: a description of two cases

Based on their clinical experience with the two cases described, the authors analyze the association between surgically treatable tear of the rotator cuff and neurologic pathology. A semeiologic sign is emphasized, which may be of help in differential diagnosis involving isolated lesion of the rotator cuff. Furthermore, after a review of the literature, the authors express doubts as to the type of surgical treatment to be carried out.