Transverse venous sinus stenting for idiopathic intracranial hypertension: Safety and feasibility

Purpose Transverse sinus stenosis is commonly seen in patients with idiopathic intracranial hypertension. It is not clear whether it is the cause or the result of idiopathic intracranial hypertension. Stenting for idiopathic intracranial hypertension has been carried out in several prior series. Our goal was to evaluate the clinical and imaging follow-up results of patients with idiopathic intracranial hypertension that underwent stenting for this condition at our center. Materials and Methods We reviewed the clinical, venographic and follow-up imaging data in patients who underwent elective transverse sinus stenting during the period from 2011 to 2017. Results In total, 18 patients with idiopathic intracranial hypertension were identified. The mean lumbar cerebrospinal fluid opening pressure recorded was 408 mmH20. Overall, 16 patients met the inclusion criteria and underwent transverse sinus stenting. At venography, the mean pressure gradient across the dominant transverse sinus stenosis was 21 mmHg. The pressure gradient immediately after stenting in all of those measured was negligible. Following stenting, headaches improved in 10 of the 16 cases, with persistent headaches in four patients, one of which had persistent baseline migraines. All cases showed resolution of the papilledema on follow up. Follow-up imaging with computed tomography venography showed that the stents remained widely patent. The follow up in clinic was done for a mean period of 35.5 months. Follow up with computed tomography venography was done for a mean of 10.3 months. Conclusion Venous sinus stenting is a safe and effective procedure. It relieves papilledema in all cases and improves headaches in most cases

Stress reactivity elicits a tissue-specific reduction in telomere length in aging zebrafish (Danio rerio).

Individual differences in personality are associated with variation in healthy aging. Health behaviours are often cited as the likely explanation for this association; however, an underlying biological mechanism may also exist. Accelerated leukocyte telomere shortening is implicated in multiple age-related diseases and is associated with chronic activation of the hypothalamus-pituitary-adrenal (HPA) axis, providing a link between stress-related personality differences and adverse health outcomes. However, the effects of the HPA axis are tissue specific. Thus, leukocyte telomere length may not accurately reflect telomere length in disease-relevant tissues. Here, we examined the correlation between stress reactivity and telomere length in heart and brain tissue in young (6-9 month) and aging (18 month) zebrafish. Stress reactivity was assessed by tank diving and through gene expression. Telomere length was assessed using quantitative PCR. We show that aging zebrafish have shorter telomeres in both heart and brain. Telomere length was inversely related to stress reactivity in heart but not brain of aging individuals. These data support the hypotheses that an anxious predisposition contributes to accelerated telomere shortening in heart tissue, which may have important implications for our understanding of age-related heart disease, and that stress reactivity contributes to age-related telomere shortening in a tissue-specific manner

Removal of TcO4- from Representative Nuclear Waste Streams with Layered Potassium Metal Sulfide Materials

Many efforts have focused on the sequestration and immobilization of 99Tc because the radionuclide is highly mobile in oxidizing environments and presents serious health risks due to its radiotoxicity and long half-life (t1/2 = 213 000 a). One of the more common methods for Tc removal from solution and immobilization in solids is based on reducing Tc from highly soluble Tc(VII) to sparingly soluble Tc(IV). Here, we report results obtained with two potassium metal sulfides (KMS-2 and KMS-2-SS) that are capable of reducing Tc(VII) to Tc(IV). Batch sorption experiments were performed in both oxic and anoxic conditions for 15 d in both deionized water (DIW) and a highly caustic (pH ∼ 13.6), high ionic strength (8.0 mol L-1), low-activity waste (LAW) stream simulant solution. Tc removal for both materials in DIW is improved in anoxic conditions compared to oxic conditions as a result of a higher solution pH. In DIW and anoxic conditions, KMS-2 is capable of removing ∼45% of Tc, and KMS-2-SS is capable of removing ∼90% of Tc. Both materials perform even better in the LAW simulant and remove more than 90% of available Tc after 15 d of contact in anoxic conditions. Postreaction solids analyses indicate that Tc(VII) is reduced to Tc(IV) and that Tc(IV) is bonded to S atoms in a Tc2S7 complex. Examination of the materials after Tc removal by X-ray diffraction shows that the initially crystalline KMS-2 materials lose much of their initial long-range order. We suggest a Tc removal mechanism wherein the TcO4- enters the interlayer of the KMS-2 materials where it is reduced by sulfide, which results in a distorted crystalline structure and a solid-state Tc2S7 complex

The influence of the atmospheric boundary layer on nocturnal layers of noctuids and other moths migrating over southern Britain

Insects migrating at high altitude over southern Britain have been continuously monitored by automatically-operating, vertical-looking radars over a period of several years. During some occasions in the summer months, the migrants were observed to form well-defined layer concentrations, typically at heights of 200-400 m, in the stable night-time atmosphere. Under these conditions, insects are likely to have control over their vertical movements and are selecting flight heights which are favourable for long-range migration. We therefore investigated the factors influencing the formation of these insect layers by comparing radar measurements of the vertical distribution of insect density with meteorological profiles generated by the UK Met. Office’s Unified Model (UM). Radar-derived measurements of mass and displacement speed, along with data from Rothamsted Insect Survey light traps provided information on the identity of the migrants. We present here three case studies where noctuid and pyralid moths contributed substantially to the observed layers. The major meteorological factors influencing the layer concentrations appeared to be: (a) the altitude of the warmest air, (b) heights corresponding to temperature preferences or thresholds for sustained migration and (c), on nights when air temperatures are relatively high, wind-speed maxima associated with the nocturnal jet. Back-trajectories indicated that layer duration may have been determined by the distance to the coast. Overall, the unique combination of meteorological data from the UM and insect data from entomological radar described here show considerable promise for systematic studies of high-altitude insect layering

Mexico City and the biogeochemistry of global urbanization

Mexico City is far advanced in its urban evolution, and cities in currently developing nations may soon follow a similar course. This paper investigates the strengths and weaknesses of infrastructures for the emerging megacities. The major driving force for infrastructure change in Mexico City is concern over air quality. Air chemistry data from recent field campaigns have been used to calculate fluxes in the atmosphere of the Valley of Mexico, for compounds that are important to biogeochemistry including methane (CH4), carbon monoxide (CO), nonmethane hydrocarbons (NMHCs), ammonia (NH3), sulfur dioxide (SO2), nitrogen oxides (NOx and NOy), soot, and dust. Leakage of liquified petroleum gas approached 10% during sampling periods, and automotive pollutant sources in Mexico City were found to match those in developed cities, despite a lower vehicle-to-person ratio of 0.1. Ammonia is released primarily from residential areas, at levels sufficient to titrate pollutant acids into particles across the entire basin. Enhancements of reduced nitrogen and hydrocarbons in the vapor phase skew the distribution of NOy species towards lower average deposition velocities. Partly as a result, downwind nutrient deposition occurs on a similar scale as nitrogen fixation across Central America, and augments marine nitrate upwelling. Dust suspension from unpaved roads and from the bed of Lake Texcoco was found to be comparable to that occurring on the periphery of the Sahara, Arabian, and Gobi deserts. In addition, sodium chloride (NaCl) in the dust may support heterogeneous chlorine oxide (ClOx) chemistry. The insights from our Mexico City analysis have been tentatively applied to the upcoming urbanization of Asia

Tendinopathy—from basic science to treatment

Chronic tendon pathology (tendinopathy), although common, is difficult to treat. Tendons possess a highly organized fibrillar matrix, consisting of type I collagen and various 'minor' collagens, proteoglycans and glycoproteins. The tendon matrix is maintained by the resident tenocytes, and there is evidence of a continuous process of matrix remodeling, although the rate of turnover varies at different sites. A change in remodeling activity is associated with the onset of tendinopathy. Major molecular changes include increased expression of type III collagen, fibronectin, tenascin C, aggrecan and biglycan. These changes are consistent with repair, but they might also be an adaptive response to changes in mechanical loading. Repeated minor strain is thought to be the major precipitating factor in tendinopathy, although further work is required to determine whether it is mechanical overstimulation or understimulation that leads to the change in tenocyte activity. Metalloproteinase enzymes have an important role in the tendon matrix, being responsible for the degradation of collagen and proteoglycan in both healthy patients and those with disease. Metalloproteinases that show increased expression in painful tendinopathy include ADAM (a disintegrin and metalloproteinase)-12 and MMP (matrix metalloproteinase)-23. The role of these enzymes in tendon pathology is unknown, and further work is required to identify novel and specific molecular targets for therapy

The Impact of the Unstructured Contacts Component in Influenza Pandemic Modeling

Individual based models have become a valuable tool for modeling the spatiotemporal dynamics of epidemics, e.g. influenza pandemic, and for evaluating the effectiveness of intervention strategies. While specific contacts among individuals into diverse environments (family, school/workplace) can be modeled in a standard way by employing available socio-demographic data, all the other (unstructured) contacts can be dealt with by adopting very different approaches. This can be achieved for instance by employing distance-based models or by choosing unstructured contacts in the local communities or by employing commuting data.Here we show how diverse choices can lead to different model outputs and thus to a different evaluation of the effectiveness of the containment/mitigation strategies. Sensitivity analysis has been conducted for different values of the first generation index G(0), which is the average number of secondary infections generated by the first infectious individual in a completely susceptible population and by varying the seeding municipality. Among the different considered models, attack rate ranges from 19.1% to 25.7% for G(0) = 1.1, from 47.8% to 50.7% for G(0) = 1.4 and from 62.4% to 67.8% for G(0) = 1.7. Differences of about 15 to 20 days in the peak day have been observed. As regards spatial diffusion, a difference of about 100 days to cover 200 km for different values of G(0) has been observed.To reduce uncertainty in the models it is thus important to employ data, which start being available, on contacts on neglected but important activities (leisure time, sport mall, restaurants, etc.) and time-use data for improving the characterization of the unstructured contacts. Moreover, all the possible effects of different assumptions should be considered for taking public health decisions: not only sensitivity analysis to various model parameters should be performed, but intervention options should be based on the analysis and comparison of different modeling choices