Changes in the use of broad-spectrum antibiotics after cefepime shortage: a time series analysis.

The original cefepime product was withdrawn from the Swiss market in January 2007, and replaced by a generic 10 months later. The goals of the study were to assess the impact of this cefepime shortage on the use and costs of alternative broad-spectrum antibiotics, on antibiotic policy, and on resistance of Pseudomonas aeruginosa towards carbapenems, ceftazidime and piperacillin-tazobactam. A generalized regression-based interrupted time series model assessed how much the shortage changed the monthly use and costs of cefepime and of selected alternative broad-spectrum antibiotics (ceftazidime, imipenem-cilastatin, meropenem, piperacillin-tazobactam) in 15 Swiss acute care hospitals from January 2005 to December 2008. Resistance of P. aeruginosa was compared before and after the cefepime shortage. There was a statistically significant increase in the consumption of piperacillin-tazobactam in hospitals with definitive interruption of cefepime supply, and of meropenem in hospitals with transient interruption of cefepime supply. Consumption of each alternative antibiotic tended to increase during the cefepime shortage and to decrease when the cefepime generic was released. These shifts were associated with significantly higher overall costs. There was no significant change in hospitals with uninterrupted cefepime supply. The alternative antibiotics for which an increase in consumption showed the strongest association with a progression of resistance were the carbapenems. The use of alternative antibiotics after cefepime withdrawal was associated with a significant increase in piperacillin-tazobactam and meropenem use and in overall costs, and with a decrease in susceptibility of P. aeruginosa in hospitals. This warrants caution with regard to shortages and withdrawals of antibiotics.

Mutations in the human UBR1 gene and the associated phenotypic spectrum.

Johanson-Blizzard syndrome (JBS) is a rare, autosomal recessive disorder characterized by exocrine pancreatic insufficiency, typical facial features, dental anomalies, hypothyroidism, sensorineural hearing loss, scalp defects, urogenital and anorectal anomalies, short stature, and cognitive impairment of variable degree. This syndrome is caused by a defect of the E3 ubiquitin ligase UBR1, which is part of the proteolytic N-end rule pathway. Herein, we review previously reported (n = 29) and a total of 31 novel UBR1 mutations in relation to the associated phenotype in patients from 50 unrelated families. Mutation types include nonsense, frameshift, splice site, missense, and small in-frame deletions consistent with the hypothesis that loss of UBR1 protein function is the molecular basis of JBS. There is an association of missense mutations and small in-frame deletions with milder physical abnormalities and a normal intellectual capacity, thus suggesting that at least some of these may represent hypomorphic UBR1 alleles. The review of clinical data of a large number of molecularly confirmed JBS cases allows us to define minimal clinical criteria for the diagnosis of JBS. For all previously reported and novel UBR1 mutations together with their clinical data, a mutation database has been established at LOVD.

Characterizing the connectome in schizophrenia with diffusion spectrum imaging.

Schizophrenia is a complex psychiatric disorder characterized by disabling symptoms and cognitive deficit. Recent neuroimaging findings suggest that large parts of the brain are affected by the disease, and that the capacity of functional integration between brain areas is decreased. In this study we questioned (i) which brain areas underlie the loss of network integration properties observed in the pathology, (ii) what is the topological role of the affected regions within the overall brain network and how this topological status might be altered in patients, and (iii) how white matter properties of tracts connecting affected regions may be disrupted. We acquired diffusion spectrum imaging (a technique sensitive to fiber crossing and slow diffusion compartment) data from 16 schizophrenia patients and 15 healthy controls, and investigated their weighted brain networks. The global connectivity analysis confirmed that patients present disrupted integration and segregation properties. The nodal analysis allowed identifying a distributed set of brain nodes affected in the pathology, including hubs and peripheral areas. To characterize the topological role of this affected core, we investigated the brain network shortest paths layout, and quantified the network damage after targeted attack toward the affected core. The centrality of the affected core was compromised in patients. Moreover the connectivity strength within the affected core, quantified with generalized fractional anisotropy and apparent diffusion coefficient, was altered in patients. Taken together, these findings suggest that the structural alterations and topological decentralization of the affected core might be major mechanisms underlying the schizophrenia dysconnectivity disorder. Hum Brain Mapp, 36:354-366, 2015. © 2014 Wiley Periodicals, Inc.

Nouveau spectre des troubles cognitifs liés à l'infection par le VIH à l'ère des trithérapies [New spectrum of HIV-associated cognitive disorders in the HAART era]

Highly active anti-retroviral therapy (HAART) has almost abolished HIV-related mortality and serious opportunistic diseases; among them, AIDS-related dementia. However, minor forms of cognitive dysfunction, have not disappeared, and even increased in frequency. Ageing of HIV+ patients, insufficient penetration of anti-viral drugs into the brain with continuous low-grade viral production and inflammation may play a role. Minor cognitive dysfunction in HIV infection shares some clinical and pathophysiological features with neuro-degenerative diseases, in particular Alzheimers disease. It can thus be postulated that, such in Alzheimer disease, anti-cholinesterase drugs might also be efficacious in AIDS-related minor cognitive dysfunction. This hypothesis has not been tested yet however A clinical trial using ravistigmine is starting this spring in patients with HIV-associated cognitive dysfunction in Geneva and Lausanne.

Composition, nanostructure, and optical properties of silver and silver-copper lusters

Lusters are composite thin layers of coinage metal nanoparticles in glass displaying peculiar optical properties and obtained by a process involving ionic exchange, diffusion, and crystallization. In particular, the origin of the high reflectance (golden-shine) shown by those layers has been subject of some discussion. It has been attributed to either the presence of larger particles, thinner multiple layers or higher volume fraction of nanoparticles. The object of this paper is to clarify this for which a set of laboratory designed lusters are analysed by Rutherford backscattering spectroscopy, transmission electron microscopy, x-ray diffraction, and ultraviolet-visible spectroscopy. Model calculations and numerical simulations using the finite difference time domain method were also performed to evaluate the optical properties. Finally, the correlation between synthesis conditions, nanostructure, and optical properties is obtained for these materials.

Tarvitaanko verkkodokumenttien kuvailussa käsityötä? : osa 2 : tietoyhteisöt ja suodatusmekanismit

Summary

Tarvitaanko verkkodokumenttien kuvailussa käsityötä? : osa 1: kontekstuaalinen metadata

Summary

3D noise power spectrum applied on clinical mdct scanners: effects of reconstruction algorithms and reconstruction filters

The noise power spectrum (NPS) is the reference metric for understanding the noise content in computed tomography (CT) images. To evaluate the noise properties of clinical multidetector (MDCT) scanners, local 2D and 3D NPSs were computed for different acquisition reconstruction parameters.A 64- and a 128-MDCT scanners were employed. Measurements were performed on a water phantom in axial and helical acquisition modes. CT dose index was identical for both installations. Influence of parameters such as the pitch, the reconstruction filter (soft, standard and bone) and the reconstruction algorithm (filtered-back projection (FBP), adaptive statistical iterative reconstruction (ASIR)) were investigated. Images were also reconstructed in the coronal plane using a reformat process. Then 2D and 3D NPS methods were computed.In axial acquisition mode, the 2D axial NPS showed an important magnitude variation as a function of the z-direction when measured at the phantom center. In helical mode, a directional dependency with lobular shape was observed while the magnitude of the NPS was kept constant. Important effects of the reconstruction filter, pitch and reconstruction algorithm were observed on 3D NPS results for both MDCTs. With ASIR, a reduction of the NPS magnitude and a shift of the NPS peak to the low frequency range were visible. 2D coronal NPS obtained from the reformat images was impacted by the interpolation when compared to 2D coronal NPS obtained from 3D measurements.The noise properties of volume measured in last generation MDCTs was studied using local 3D NPS metric. However, impact of the non-stationarity noise effect may need further investigations.

Clinical spectrum of tuberculous optic neuropathy.

PURPOSE: Tuberculous optic neuropathy may follow infection with Mycobacterium tuberculosis or administration of the bacille Calmette-Guerin. However, this condition is not well described in the ophthalmic literature. METHODS: Ophthalmologists, identified through professional electronic networks or previous publications, collected standardized clinical data relating to 62 eyes of 49 patients who they had managed with tuberculous optic neuropathy. RESULTS: Tuberculous optic neuropathy was most commonly manifested as papillitis (51.6 %), neuroretinitis (14.5 %), and optic nerve tubercle (11.3 %). Uveitis was an additional ocular morbidity in 88.7 % of eyes. In 36.7 % of patients, extraocular tuberculosis was present. The majority of patients (69.4 %) had resided in and/or traveled to an endemic area. Although initial visual acuity was 20/50 or worse in 62.9 % of 62 eyes, 76.7 % of 60 eyes followed for a median of 12 months achieved visual acuities of 20/40 or better. Visual field defects were reported for 46.8 % of eyes, but these defects recovered in 63.2 % of 19 eyes with follow-up. CONCLUSION: Visual recovery from tuberculous optic neuropathy is common, if the diagnosis is recognized and appropriate treatment is instituted. A tuberculous etiology should be considered when evaluating optic neuropathy in persons from endemic areas.