[Medical devices used in digestive system surgical procedures: What's the cost?] / Dépenses en dispositifs médicaux stériles dans certains actes de chirurgie hépatobiliaire et digestive : que resterait-il du Groupe Homogène de Séjour ?

OBJECTIVE: Medical devices innovations and associated procedures represent a large part of health facilities budget. The aim of this work was to evaluate the cost of medical devices used during different surgical procedures. This cost was compare with the revenue collected from hospital stay pricing. METHOD: A prospective analysis of the medical devices used in operating room was carried out for different types of programmed surgeries. For five weeks, references of sterile single-use medical devices used during the interventions were collected. RESULTS: Expenditure on medical devices used during surgical procedures represented 5.7 % of the hospitalization value for an inguinal hernia repair, 12 % for a cholecystectomy, 9.35 % for a colectomy, 14.5 % for a hepatectomy and 7 % for pancreatectomy, any severity index combined. The most important correlations existed between act duration and patient's level of severity and between operating times and consumables expenditure. CONCLUSION: Cost optimization opportunities are equivalence of some medical devices ranges, purchases with national groupings and potential decreases in operating times related to the use of innovative medical devices.

Transfer characteristics of subretinal visual implants: corneally recorded implant responses.

PURPOSE: The subretinal Alpha IMS visual implant is a CE-approved medical device for restoration of visual functions in blind patients with end-stage outer retina degeneration. We present a method to test the function of the implant objectively in vivo using standard electroretinographic equipment and to assess the devices' parameter range for an optimal perception. METHODS: Subretinal implant Alpha IMS (Retina Implant AG, Reutlingen, Germany) consists of 1500 photodiode-amplifier-electrode units and is implanted surgically into the subretinal space in blind retinitis pigmentosa patients. The voltages that regulate the amplifiers' sensitivity (V gl) and gain (V bias), related to the perception of contrast and brightness, respectively, are adjusted manually on a handheld power supply device. Corneally recorded implant responses (CRIR) to full-field illumination with long duration flashes in various implant settings for brightness gain (V bias) and amplifiers' sensitivity (V gl) are measured using electroretinographic setup with a Ganzfeld bowl in a protocol of increasing stimulus luminances up to 1000 cd/m2. RESULTS: CRIRs are a meaningful tool for assessing the transfer characteristic curves of the electronic implant in vivo monitoring the implants' voltage output as a function of log luminance in a sigmoidal shape. Changing the amplifiers' sensitivity (V gl) shifts the curve left or right along the log luminance axis. Adjustment of the gain (V bias) changes the maximal output. Contrast perception is only possible within the luminance range of the increasing slope of the function. CONCLUSIONS: The technical function of subretinal visual implants can be measured objectively using a standard electroretinographic setup. CRIRs help the patient to optimise the perception by adjusting the gain and luminance range of the device and are a useful tool for clinicians to objectively assess the function of subretinal visual implants in vivo.

Enzyme replacement therapy for mucopolysaccharidosis VI: long-term cardiac effects of galsulfase (Naglazyme®) therapy.

Characteristic cardiac valve abnormalities and left ventricular hypertrophy are present in untreated patients with mucopolysaccharidosis type VI (MPS VI). Cardiac ultrasound was performed to investigate these findings in subjects during long-term enzyme replacement therapy (ERT) with recombinant human arylsulfatase B (rhASB, rhN-acetylgalactosamine 4-sulfatase, galsulfase, Naglazyme®). Studies were conducted in 54 subjects before ERT was begun and at specific intervals for up to 96 weeks of weekly infusions of rhASB at 1 mg/kg during phase 1/2, phase 2, and phase 3 trials of rhASB. At baseline, mitral and aortic valve obstruction was present and was significantly greater in those ≥12 years of age. Mild mitral and trace aortic regurgitation were present, the former being significantly greater in those <12 years. Left ventricular hypertrophy, with averaged z-scores ranging from 1.6-1.9 SD greater than normal, was present for ages both <12 and ≥12 years. After 96 weeks of ERT, ventricular septal hypertrophy regressed in those <12 years. For those ≥12 years, septal hypertrophy was unchanged, and aortic regurgitation increased statistically but not physiologically. Obstructive gradients across mitral and aortic valves remained unchanged. The results suggest that long-term ERT is effective in reducing intraventricular septal hypertrophy and preventing progression of cardiac valve abnormalities when administered to those <12 years of age.

Characteristics of the 100 largest modern zoonotic disease outbreaks.

Zoonotic disease outbreaks are an important threat to human health and numerous drivers have been recognized as contributing to their increasing frequency. Identifying and quantifying relationships between drivers of zoonotic disease outbreaks and outbreak severity is critical to developing targeted zoonotic disease surveillance and outbreak prevention strategies. However, quantitative studies of outbreak drivers on a global scale are lacking. Attributes of countries such as press freedom, surveillance capabilities and latitude also bias global outbreak data. To illustrate these issues, we review the characteristics of the 100 largest outbreaks in a global dataset (n = 4463 bacterial and viral zoonotic outbreaks), and compare them with 200 randomly chosen background controls. Large outbreaks tended to have more drivers than background outbreaks and were related to large-scale environmental and demographic factors such as changes in vector abundance, human population density, unusual weather conditions and water contamination. Pathogens of large outbreaks were more likely to be viral and vector-borne than background outbreaks. Overall, our case study shows that the characteristics of large zoonotic outbreaks with thousands to millions of cases differ consistently from those of more typical outbreaks. We also discuss the limitations of our work, hoping to pave the way for more comprehensive future studies. This article is part of the theme issue 'Infectious disease macroecology: parasite diversity and dynamics across the globe'.

[Transcorneal electrical stimulation in primary open angle glaucoma]. / Transkorneale Elektrostimulation bei primärem Offenwinkelglaukom.

Recently, reports have been published on the effectiveness of electrical stimulation in patients and experimental animal models with neurodegenerative ocular diseases. Our study included 14 patients with primary open angle glaucoma (POAG), who were randomized into one of three groups with 0% (sham, n = 5), 66% (n = 5) or 150% (n = 4) of their individual electrical phosphene thresholds. Patients were treated with transcorneal electrical stimulation (TES) for 30 min once a week for 6 consecutive weeks. Outcome measures of our study were the detection of possible adverse events and efficacy of TES using DTL electrodes in subjective and objective parameters of visual function under treatment. TES was tolerated well and no serious adverse events were registered relating to the treatment. One single adverse event was registered as appearance of an optic disc hemorrhage of a sham-stimulated eye. In summary, one significant increase of intra-ocular pressure in the 66% group was observed in comparison to the sham group (p = 0.04), without significant differences compared to the 150% group (both sham vs. 150% group and 66% vs. 150% group). This difference (mean difference compared to baseline of -2.33 mm Hg for the sham group and +0.97 mm Hg for the 66% group; REML) was not clinical meaningful. All other findings, including results of the visual field, were not statistically significant different between groups. It was shown that TES using DTL electrodes did not trigger adverse or serious adverse events in the stimulated groups in patients with POAG. Patients with POAG should currently receive TES only under study conditions.

In vivo biocompatibility of a new cyanine dye for ILM peeling.

PURPOSE: To investigate the biocompatibility of the new cyanine dye: 3,3'-Di-(4-sulfobutyl)-1,1,1',1'-tetramethyl-di-1H-benz[e]indocarbocyanine (DSS) as a vital dye for intraocular application in an in vivo rat model and to evaluate the effects of this dye on retinal structure and function. METHODS: DSS at a concentration of 0.5% was applied via intravitreal injections to adult Brown Norway rats with BSS serving as a control. Retinal toxicity was assessed 7 days later by means of retinal ganglion cell (RGC) counts, light microscopy, optical coherence tomography (OCT), and electroretinography (ERG). RESULTS: No significant decrease in RGC numbers was observed. No structural changes of the central retina were observed either in vivo (OCT) or under light microscopy. ERGs detected a temporary reduction of retinal function 7 days after injection; this was no longer evident 14 days after injection. CONCLUSIONS: DSS showed good biocompatibility in a well-established experimental in vivo setting and may be usable for intraocular surgery as an alternative to other cyanine dyes. In contrast to indocyanine green, it additionally offers fluorescence in the visual spectrum. Further studies with other animal models are needed before translation into clinical application.

Identification of an endogenous 2-monoglyceride, present in canine gut, that binds to cannabinoid receptors.

In this study, we report the isolation from canine intestines of 2-arachidonyl glycerol (2-Ara-Gl). Its structure was determined by mass spectrometry and by direct comparison with a synthetic sample. 2-Ara-Gl bound to membranes from cells transiently transfected with expression plasmids carrying DNA of either CB1 or CB2--the two cannabinoid receptors identified thus far--with Ki values of 472 +/- 55 and 1400 +/- 172 nM, respectively. In the presence of forskolin, 2-Ara-Gl inhibited adenylate cyclase in isolated mouse spleen cells, at the potency level of delta 9-tetrahydrocannabinol (delta 9-THC). Upon intravenous administration to mice, 2-Ara-Gl caused the typical tetrad of effects produced by THC: antinociception, immobility, reduction of spontaneous activity, and lowering of the rectal temperature. 2-Ara-Gl also shares the ability of delta 9-THC to inhibit electrically evoked contractions of mouse isolated vasa deferentia; however, it was less potent than delta 9-THC.

Inhibition of adenylate cyclase by delta 9-tetrahydrocannabinol in mouse spleen cells: a potential mechanism for cannabinoid-mediated immunosuppression.

The ability of delta 9-Tetrahydrocannabinol (delta 9-THC) to modulate adenylate cyclase activity in mouse spleen cells was investigated. These studies were prompted by the recent identification and cloning of a G-protein coupled cannabinoid receptor localized in certain regions of the brain and the potential for a common mechanism between cannabinoid-mediated CNS effects and immunosuppression. Temporal addition studies were initially performed to identify the period of time when spleen cells in culture were most susceptible to the inhibitory effects of delta 9-THC, as measured by the day 5 IgM antibody forming cell response. delta 9-THC was only inhibitory when added to spleen cell cultures during the first 2 hr following antigen sensitization. In light of this time course, adenylate cyclase activity was measured in spleen cells incubated in the presence of 22 microM delta 9-THC for 5 min and subsequently stimulated with forskolin. delta 9-THC treated spleen cells demonstrated a 33% inhibition and a 66% inhibition in intracellular cAMP after a 5 or 15 min stimulation with forskolin, respectively. These studies suggest that inhibition of immune function by delta 9-THC may be mediated through the inhibition of intracellular cAMP early after antigen stimulation.

A hierarchical analysis of block design errors in children with early focal brain damage.

This study investigated the differential effects of very early damage to the left hemisphere (LH) or right hemisphere (RH) on visuospatial processing. Twenty-two children who had suffered either LH or RH strokes in the pre- or perinatal period were included in the study. The Block Design subtest of the Wechsler Intelligence Scale for Children-Revised (Wechsler, 1974) was used. Each missed item was coded as either a global error (e.g., broken configuration), local error (e.g., incorrect details), or time fail error (i.e., not completed within the allotted time). Results showed that the LH lesion and RH lesion groups had similar full scale IQs, verbal IQs, and performance IQs and were within the average to low average range. Block Design scaled scores were also within the average to low average range and did not significantly differ between the 2 lesion groups. Error analysis revealed, however, that the RH focal lesion group produced a significantly higher percentage of global errors than did the LH lesion group, whereas the LH lesion group produced a significantly higher percentage of local errors than did the RH lesion group. The groups did not differ on their percentage of time fail errors. These results are consistent with previous findings that suggest that the RH is involved in more global aspects of visual processing, whereas the LH mediates the more detailed, local aspects of visual information. The fact that these differences in processing are present after such early focal damage implies that hemispheric specialization for visuospatial processing occurs very early in brain development.

"Motor" impairment in Asperger syndrome: evidence for a deficit in proprioception.

Motor impairment has frequently been described in Asperger syndrome (AS), a pervasive developmental disorder included in the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV). Previous research focusing on this motor dysfunction has yielded inconsistent results, and the "clumsiness" observed clinically remains poorly defined. To clarify further the issue of motor impairment, we compared a group of 10 children and young adults who met DSM-IV criteria for AS with a control group with no neurological impairment. Subjects were matched on age, sex, socioeconomic status, and Verbal IQ. A broad battery of motoric tests was administered. Subjects with AS were found to perform more poorly than controls on tests of apraxia, one-leg balance with eyes closed, tandem gait, and repetitive finger-thumb apposition. No significant differences were found on tests of finger tapping, grooved pegboard, trail making, or visual-motor integration. The pattern of impairments suggests that a proprioceptive deficit may underlie the incoordination observed in AS and that these individuals may be overreliant on visual input to maintain balance and position in space.

Gravity and the membrane-solution interface: theoretical investigations.

The theory of concentration and potential variations at interfaces is applied to the membrane-solution interface to calculate density variations. The theory is modified to take care of the finite ion volumes in electrolytes. Our model is a phospholipid membrane with a surface charge density of -4.824*10(-6)(As/cm2) in contact with solutions of KCl, NaCl, CaCl2, and mixtures. Maximal density variations of about 4*10(-2)(G/cm3) were found in surface layers between the membrane and the solutions. The extension of the layers is in the range of 1 to 6 nm.

Light microscopic analysis of the gravireceptor in Xenopus larvae developed in hypogravity.

The paper describes an investigation of the influence of gravity on the early differentiation of gravity receptors in Xenopus embryos and larvae. There is evidence that the expression of crystals in the saccus endolymphaticus was statistically greater when the embryos developed in near weightlessness (hypogravity) than on earth. The function of these crystals is unknown but they may contribute to the functioning of the vestibular apparatus.

The reaction of Xenopus laevis Daudin (South African toad) to linear accelerations.

Preparing the German Spacelab Mission D-2 project "Gravity Perception and Neuronal Plasticity"--STATEX II--ground based experiments have been performed with larvae of the amphibian vertebrate Xenopus laevis Daud. to study the reactions to different levels of acceleration forces and profiles. The larvae have been exposed to accelerations of up to 5 g for different time periods using a modified laboratory centrifuge and the NIZEMI (Niedergeschwindigkeits-Zentrifugen-Mikroskop) which allows direct observation and video documentation. The results will be discussed and compared with those of the D1-Mission, parabolic flights, and simulated weightlessness.

Functional weightlessness during clinorotation of cell suspensions.

A clinostat is a device often used in gravitational biology studies. Selecting an appropriate speed of rotation, however, is a frequently debated topic, particularly for suspended cells. In an attempt to define the necessary criteria for determining an acceptable revolution speed, the primary forces governing particle behavior during clinorotation--gravity, diffusion and centrifugation--were mathematically assessed. In support of the theoretical exercise, bacterial growth experiments indicated that results obtained using a clinostat followed trends resembling previous space flight results. It is suspected that this is due, in part at least, to similarly altered external transport processes in each environment.

Gravity effects on biological systems.

Theoretical investigations of the membrane-solution interface predict different effects of gravity on vertically and horizontally oriented planar membranes. Single channel events of gramicidin incorporated into phosphatidylserine planar bilayer membranes were measured in 0.1 M KCl solution, pH 7, at room temperature. The potential difference across the membrane was set to +/- 70 mV. The mean channel current was observed to be about 20% higher in horizontally oriented membranes compared to vertical membranes. This is in good agreement with the theoretical considerations and demonstrates that gravity does affect membrane processes by interaction with the membrane-solution interface which is a ubiquitous structure in biological systems.

Survey of the vestibulum, and behavior of Xenopus laevis larvae developed during a 7-days space flight.

Aquatic animals have almost no body weight related proprioception for spatial orientation. Xenopus larvae, like fish, maintain their attitude in water by continuous correction with their fin(s). For these reasons a special performance of the equilibrium system compared to terrestrial animals is necessary. Evidently fish therefore have more compact (dense) otoliths; Xenopus larvae have less dense otolith (membranes) similar to land vertebrates; but their sacculus-otoliths are vertically positioned, which also may lead to a higher g-sensitivity. For plausibility reasons gravity should influence the embryonic development of gravity receptors. Yet, evaluations of photographs taken from the surface of cut deep-frozen objects by incident light show no aberration of the shape of the whole vestibulum and of the shape, density, size and position of the otolith membrane in larvae developed under near-zero g (NEXPA-BW-STATEX in D-1-Mission). The further evaluation of the "weightless-larvae" revealed a probably not yet described statolith-like formation in the dorsal wall of the vestibulum. In the weightless larvae this formation outnumbers, also qualitatively, strongly the l-g controls. An extra result is the lack of striking effects of cosmic radiation on the embryonic development of the flown Xenopus eggs. The swimming behavior of the larvae which was observed about one hour after landing of the Space Shuttle showed a typical anomaly (loop swimming), which is known from larvae developed on the clinostat or from fish flown aboard Apollo capsules.

Effects of gravity on early development.

The development of embryonic and larval stages of the South African Toad Xenopus laevis D, was investigated in hyper-g up to 5 g (centrifuge), in simulated 0 g (fast-rotating clinostat), in alternating low g, hyper-g (parabolic flights) and in microgravity (Spacelab missions D1, D-2). The selected developmental stages are assumed to be very sensitive to environmental stimuli. The results showed that the developmental reaction processes run normal also in environments different to 1 g and that aberrations in behavior and morphology normalize after return to 1 g. Development, differentiation, and morphology of the gravity perceiving parts of the vestibular system (macula-organs) had not been affected by exposure to different g-levels.

Gravity effects on membrane processes.

Application of the Gouy-Chapman-Debye-Hückel (GCDH) theory to a model membrane in contact with electrolytes of various concentrations and composition predict density variations within an interfacial layer. Assuming that on cellular dimensions hydrodynamics can be applied (the objections are briefly discussed) two types of gravity effects can be defined, 1. convection along the surface of vertically oriented membranes and 2. surface potential variations by layer deformations at horizontally oriented membranes. Both effects should affect transport across the layer to the membrane surface and across the membrane. According to the theoretical predictions first experiments with gramicidin channels incorporated into artificial phosphatidylserine bilayer membranes show a significant difference in single channel currents in vertical and horizontal membranes. The complexity of biological membrane functions requires investigation of isolated membrane surface reactions and transport systems to study the gravisensitivity for each process separately.

Early development in aquatic vertebrates in near weightlessness during the D-2 Mission STATEX project.

Aboard the German-Spacelab-Mission D-2 the project "Gravity Perception and Neuronal Plasticity (STATEX II)" was performed. STATEX is for STATolith EXperiment. Objects were growing tadpoles of the South African Toad (Xenopus laevis D.) and a juvenile cichlid fish (Oreochromis mossambicus). The results give a broader base for the understanding of how environmental stimuli (e.g. linear accelerations) affect the development and function of the gravity perceiving systems in these two vertebrates. These systems are accepted as models for the human vestibulum. Results of experiments in hyper-g (up to 5 g), simulated weightlessness (Fast-rotating-clinostat) and parabolic flights are compared and discussed.

Sensitivity and specificity of a computerized test of attention in the diagnosis of Attention-Deficit/Hyperactivity Disorder.

Attention-Deficit/Hyperactivity Disorder (ADHD) is difficult to diagnose due to the subjectivity of its symptoms and lack of specific assessment measures. Computerized tests of attention have recently been used as objective measures that may assist in the diagnosis of the disorder. The present study evaluated consistency between the Conners Parent Rating Scale and the Test of Variables of Attention (TOVA), which is a computerized test of attention designed to identify symptoms associated with ADHD, in children clinically diagnosed with ADHD (n = 28) and controls (n = 20). Our results showed that both the Conners and the TOVA indicated significant problem areas suggestive of an attention deficit in approximately 85% of children who were clinically diagnosed with ADHD. However, the TOVA also found attentional problems in approximately 30% of control children, whereas none of the controls scored abnormally on the Conners. As computerized measures are administered more frequently, there may be a risk of overdiagnosis and treatment of "ADHD" in normal children. A combined approach using questionnaires, clinical evaluation, and computerized tests of attention in the assessment of possible ADHD may provide the most accurate means of diagnosis.