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Objective: To describe the heterogeneity of electrodiagnostic (EDx) studies in Guillain-Barre syndrome (GBS) patients collected as part of the International GBS Outcome Study (IGOS). Methods: Prospectively collected clinical and EDx data were available in 957 IGOS patients from 115 centers. Only the first EDx study was included in the current analysis. Results: Median timing of the EDx study was 7 days (interquartile range 4-11) from symptom onset. Methodology varied between centers, countries and regions. Reference values from the responding 103 centers were derived locally in 49%, from publications in 37% and from a combination of these in the remaining 15%. Amplitude measurement in the EDx studies (baseline-to-peak or peak-to-peak) differed from the way this was done in the reference values, in 22% of motor and 39% of sensory conduction. There was marked variability in both motor and sensory reference values, although only a few outliers accounted for this. Conclusions: Our study showed extensive variation in the clinical practice of EDx in GBS patients among IGOS centers across the regions. Significance: Besides EDx variation in GBS patients participating in IGOS, this diversity is likely to be present in other neuromuscular disorders and centers. This underlines the need for standardization of EDx in future multinational GBS studies.(c) 2022 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Recent advances in techniques for high-pressure and high-temperature experiments enable us to measure the velocity of sound in liquid Fe alloys. However, reported velocities in liquid Fe–S differ among research groups (e.g., by >10% at 5 GPa), even when similar methods are used (i.e., the ultrasonic pulse–echo overlap method combined with a large volume press). To identify the causes of the discrepancies, we reanalyzed previous data and conducted additional sound velocity measurements for liquid Fe–S at 2–7 GPa, and evaluated the potential error sources. We found that the discrepancy cannot be explained by errors in the sound velocity measurements themselves, but by inaccuracies in determining the temperature, pressure, and chemical composition in each experiment. Of particular note are the significant errors introduced when determining pressures from the unit-cell volume of MgO, which is a temperature-sensitive pressure standard, using inaccurate temperatures. To solve the problem, we additionally used h-BN as a pressure standard, which is less sensitive to temperature. The pressure dependence of the sound velocity became smaller than that of the original data because of the revised pressure values. Our best estimate for the seismic velocity of the Moon’s liquid outer core is 4.0 ± 0.1 km/s, given a chemical composition Fe 83 S 17 .

Physical and biogeochemical characteristics of the aquatic environment that affect growth dynamics of phytoplankton and the zooplankton communities that depend on them may also affect uptake of methylmercury (MeHg) into the pelagic food web of oligotrophic reservoirs. We evaluated changes in the quality and quantity of suspended particulate material, zooplankton taxonomy, and MeHg concentrations coincident with seasonal changes in water storage of a mining-impacted reservoir in northern California, USA. MeHg concentrations in bulk zooplankton increased from 4 ng·g–1at low water to 77 ± 6.1 ng·g–1at high water and were positively correlated with cladoceran biomass (r = 0.66) and negatively correlated with rotifer biomass (r = –0.65). Stable isotope analysis revealed overall higher MeHg concentrations in the pelagic-based food web relative to the benthic-based food web. Statistically similar patterns of trophic enrichment of MeHg (slopes) for the pelagic and benthic food webs and slightly higher MeHg concentrations in zooplankton than in benthic invertebrates suggest that the difference in MeHg bioaccumulation among trophic pathways is set at the base of the food webs. These results suggest an important role for plankton dynamics in driving the MeHg content of zooplankton and ultimately MeHg bioaccumulation in top predators in pelagic-based food webs.

Guadalupe Reservoir (GUA), California, and Lahontan Reservoir (LAH), Nevada, U.S. are both affected either directly or indirectly by the legacy of gold and silver mining in the Sierra Nevada during the nineteenth century. Analysis of total mercury in fish from these lentic systems consistently indicate elevated concentrations (1 microg x g(-1) wet weight; hereinafter, all concentrations are reported as wet weight unless indicated otherwise) well above the U.S. Environmenal Protection Agency's human consumption advisory level for fish (0.3 microg x g(-1)). Replicate X-ray absorption near edge structure (XANES) analyses on largemouth bass and hybrid striped bass from GUA and LAH were performed to determine predominant chemical species of mercury accumulated by these high-trophic-level piscivores that are exposed to elevated mercury through trophic transfer in mining-impacted lentic systems. Despite distinct differences in mercury source, the proximity of the source, and concentrations of complexing ligands, results of XANES analysis clearly indicated that mercury accumulated in these individual fish from the two reservoirs were dominated by methylmercury cysteine complexes. These findings are consistent with results from commercial fish species inhabiting marine environments which are presumed to include differing mercury sources (e.g., atmospheric, hydrothermal, or benthic). The dominance of methylmercury cysteine complexes in muscle tissues of fish obtained from such contrasting environments and exposure conditions suggests that a generic toxicological model for the consumption of fish could be applicable over a wide range of ecologic settings.

The two-dimensional numerical model ELAmet was used to investigate the effect of adsorption kinetics on the apparent distribution coefficients of Cu, Cd, and Zn in south San Francisco Bay, California. The numerical experiments were designed to determine whether adsorption kinetics can control the basin-scale variability of the observed partitioning and to define the conditions under which adsorption kinetics could account for strong interannual variability in partitioning. The numerical results indicate that aqueous speciation will control basin-scale spatial variations in the apparent distribution coefficient, K,“, if the system is close to equilibrium. However, basin-scale spatial variations in Kdu are determined by the location of the sources of metal and the suspended solids concentration of the receiving water if the system is far from equilibrium. The overall spatial variability in Kda also increases as the system moves away from equilibrium.

It is demonstrated that the multiple internal reflection infrared (IR) spectroscopy using a germanium prism is a very powerful nondestructive diagnostic technique for the study of silicon wafer surfaces in a wide range of IR irradiation region. The technique limits neither the shape of samples nor the IR range due to the absorption by silicon itself. With this technique, it is demonstrated that; (i) dangling bonds of a silicon surface treated with HF solution and de‐ionized (DI) water are terminated mostly with H atoms, (ii) native oxide growth is enhanced by DI water rinsing, and the interstitial oxygen concentration in the silicon surface region increases during native oxide growth process, and (iii) DI water rinsing after HF etching replaces Si—F bonds with Si—H and Si—OH bonds on a silicon surface.

The presence of a projection from the primary motor cortex to the ipsilateral muscles has been established in human, but whether this pathway contributes to functional recovery after stroke is unclear. We investigated whether the ipsilateral tract is activated in hemiparetic stroke.Motor-evoked potentials (MEPs) were simultaneously recorded from the bilateral trapezius or abductor digiti minimi (ADM) muscles after magnetic stimulation to the motor cortex in 40 acute stroke patients.At rest, ipsilateral trapezius MEPs were recordable in none of the 24 normal controls, and in 38% of the patients after stimulation to the non-affected hemisphere (P0.001). With voluntary contraction, ipsilateral trapezius MEPs were elicited in 21% of the normal controls and 73% of the patients (P0.001). Ipsilateral ADM MEPs were rarely recordable in both controls (0%) and patients (3%). The presence of ipsilateral trapezius MEPs was associated with less severe paresis in the trapezius (P = 0.04) and deltoid (P = 0.07), but not in the more distal muscles.The ipsilateral cortico-spinal tract is acutely facilitated after stroke in the trunk or proximal muscles, but not in the hand muscles. Activation of such pathway appears to partly compensate motor dysfunction of the trunk/proximal muscles.

Conception et utilisation de l'appareillage pour concentrer des bacteries et des particules en suspensions a partir de grands volumes d'echantillons d'eau de surface et souterraine, de l'ordre de la centaine de litre

To investigate whether or not the pattern and extent of autonomic involvement differ between the two subtypes of Guillain-Barré syndrome (GBS), namely acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN).Head-up tilt test, R-R interval variation, plasma noradrenaline concentration, skin vasomotor reflex (SVR) and sympathetic sweat response (SSwR) were used to estimate autonomic function in seven AIDP and eight AMAN patients.Heart rate and plasma noradrenaline concentration were significantly high in the AIDP group but not in the AMAN group. Skin vasomotor reflexes were generally preserved and SSwRs were impaired in patients with severe neurological deficits for both AIDP and AMAN groups.The patterns of autonomic involvement are qualitatively different between AIDP and AMAN. Acute inflammatory demyelinating polyneuropathy is characterized by cardio-sympathetic hyperactivity, excessive or reduced sudomotor function and preserved skin vasomotor function, while AMAN is not necessarily generally associated with marked autonomic dysfunction except for the sudomotor hypofunction seen in patients with severe neurological deficits.

To clarify the relations of the axonal form of Guillain-Barré syndrome (GBS) to anti-ganglioside antibodies and Campylobacter jejuni infection, 86 consecutive Japanese GBS patients were studied. Electrodiagnostic criteria showed acute inflammatory demyelinating polyneuropathy in 36% of the patients and acute motor axonal neuropathy (AMAN) in 38%. Frequent anti-ganglioside antibodies were of the IgG class and against GM1 (40%), GD1a (30%), GalNAc-GD1a (17%), and GD1b (21%). Identified infections were C. jejuni (23%), cytomegalovirus (10%), Mycoplasma pneumoniae (6%), and Epstein-Barr virus (3%). There was a strong association between AMAN and IgG antibodies against GM1, GD1a, GalNAc-GD1a, or GD1b. Almost all the patients with at least one of these antibodies had the AMAN pattern or rapid resolution of conduction slowing/block possibly because of early-reversible changes on the axolemma. C. jejuni infection was frequently associated with AMAN or anti-ganglioside antibodies, but more than half of the patients with AMAN or anti-ganglioside antibodies were C. jejuni-negative. These findings suggest that the three phenomena "axonal dysfunctions (AMAN or early-reversible conduction failure)," "IgG antibodies against GM1, GD1a, GalNAc-GD1a, or GD1b," and "C. jejuni infection" are closely associated but that microorganisms other than C. jejuni frequently trigger an anti-ganglioside response and elicit axonal GBS.

To investigate the pathophysiological role of anti-GM1 antibody in Guillain-Barré syndrome (GBS), we reviewed sequential nerve conduction studies of 345 nerves in 34 GBS patients. Statistically significant correlation between IgG anti-GM1 antibodies and electrodiagnoses was found. Sixteen IgG anti-GM1-positive patients were classified as having acute motor or acute motor sensory axonal neuropathy (AMAN or AMSAN) (12 patients), as having acute inflammatory demyelinating polyneuropathy (AIDP) (3 patients), or as undetermined (1 patient) by electrodiagnostic criteria. Besides axonal features, there was rapid resolution of conduction slowing and block. In 3 patients initially diagnosed as having AIDP, conduction slowing was resolved within days, and 1 of them and 3 AMAN patients showed markedly rapid increases in amplitudes of distal compound muscle action potentials that were not accompanied by prolonged duration and polyphasia. The time courses of conduction abnormalities were distinct from those in IgG anti-GM1-negative AIDP patients. Rapid resolution of conduction slowing and block, and the absence of remyelinating slow components, suggest that conduction failure may be caused by impaired physiological conduction at the nodes of Ranvier. Reversible conduction failure as well as axonal degeneration constitutes the pathophysiological mechanisms in IgG anti-GM1-positive GBS. In both cases, immune-mediated attack probably occurs on the axolemma of motor fibers.

Three collecting trips were coordinated in April, May, and August 2006 to sample the water column and benthos of hypereutrophic Upper Klamath Lake (OR, USA) through the annual cyanophyte bloom of Aphanizomenon flos-aquae. A pore-water profiler was designed and fabricated to obtain the first high-resolution (centimeter-scale) estimates of the vertical concentration gradients of macro- and micronutrients for diffusive-flux determinations. A consistently positive benthic flux for soluble reactive phosphorus (SRP) was observed with solute release from the sediment, ranging between 0.4 and 6.1 mg/m(2)/d. The mass flux over an approximate 200-km(2) lake area was comparable in magnitude to riverine inputs. An additional concern related to fish toxicity was identified when dissolved ammonium also displayed consistently positive benthic fluxes of 4 to 134 mg/m(2)/d, again comparable to riverine inputs. Although phosphorus was a logical initial choice by water quality managers for the limiting nutrient when nitrogen-fixing cyanophytes dominate, initial trace-element results from the lake and major inflowing tributaries suggested that the role of iron limitation on primary productivity should be investigated. Dissolved iron became depleted in the lake water column during the course of the algal bloom, while dissolved ammonium and SRP increased. Elevated macroinvertebrate densities, at least of the order of 10(4) individuals/m(2), suggested that the diffusive-flux estimates may be significantly enhanced by bioturbation. In addition, heat-flux modeling indicated that groundwater advection of nutrients could also significantly contribute to internal nutrient loading. Accurate environmental assessments of lentic systems and reasonable expectations for point-source management require quantitative consideration of internal solute sources.

A mathematically linked mercury transport, speciation, kinetic, and simple biotic uptake (BIOTRANSPEC) model has been developed. An extension of the metal transport and speciation (TRANSPEC) model, BIOTRANSPEC estimates the fate and biotic uptake of inorganic (Hg(II)), elemental (Hg(0)) and organic (MeHg) forms of mercury and their species in the dissolved, colloidal (e.g., dissolved organic matter [DOM]), and particulate phases of surface aquatic systems. A pseudo-steady state version of the model was used to describe mercury dynamics in Lahontan Reservoir (near Carson City, NV, USA), where internal loading of the historically deposited mercury is remobilized, thereby maintaining elevated water concentrations. The Carson River is the main source of total mercury (THg), of which more than 90% is tightly bound in a gold-silver-mercury amalgam, to the system through loadings in the spring, with negligible input from the atmospheric deposition. The speciation results suggest that aqueous species are dominated by Hg-DOM, Hg(OH)(2), and HgClOH. Sediment-to-water diffusion of MeHg and Hg-DOM accounts for approximately 10% of total loadings to the water column. The water column acts as a net sink for MeHg by reducing its levels through two competitive processes: Uptake by fish, and net MeHg demethylation. Although reservoir sediments produce significant amounts of MeHg (4 g/d), its transport from sediment to water is limited (1.6 g/d), possibly because of its adsorption on metal oxides of iron and manganese at the sediment-water interface. Fish accumulate approximately 45% of the total MeHg mass in the water column, and 9% of total MeHg uptake by fish leaves the system because of fishing. Results from this new model reiterate the previous conclusion that more than 90% of THg input is retained in sediment, which perpetuates elevated water concentrations.

Requirements of Macrocystis pyrifera (L.) C.A. Agardh (giant kelp) for nine nutrient elements (N, P, Mn, Fe, Co, Cu, Zn, Mo, I) were established by batch culturing settled spores, through the gametophytic phase, to production of embryonic sporophytes in Aquil, a chemically defined, artificial seawater medium. The ultimately successful medium resulted from ten sequential culturing series, applying an optimization technique to improve each succeeding formulation.

A procedure for conducting adsorption studies at low suspended solid concentrations in natural waters (

Spatial distributions of copper (Cu), zinc (Zn) and cadmium (Cd) were followed along a longitudinal gradient of dissolved organic carbon (DOC) in South San Francisco Bay (herein referred to as the South Bay). Dissolved Cu, Zn and Cd concentrations ranged from 24 to 66 nM, from 20 to 107 nM and from 1·2 to 4·7 nM, respectively, in samples collected on five dates beginning with the spring phytoplankton bloom and continuing through summer,1985. Dissolved Cu and Zn concentrations varied indirectly with salinity and directly with DOC concentration which ranged from 2·1 to 4·1 mg l−1. Available thermodynamic data strongly support the hypothesis that Cu speciation may be dominated by association with dissolved organic matter. Analogous control of Zn speciation by organic complexation was, however, not indicated in our computations. Computed free ion activity estimates for Cu, Zn and Cd were of the order of 10−10, 10−8 and 10−10 M, respectively. The availability of these metals may be among the factors regulating the growth of certain phytoplankton species within this region of the estuary. In contrast to dissolved Cu, dissolved Cd was directly related to the concentration of suspended particulate matter, suggesting a source of dissolved Cd coincident with elevated particle concentrations in the South Bay (e.g. runoff and solute desorption). Consistent with work in other estuaries, partitioning of all three trace metals onto suspended particulates was negatively correlated with salinity and positively correlated with increases in particulate organic carbon associated with the phytoplankton bloom. These results for the South Bay indicate that sorption processes influence dissolved concentrations of these trace metals, the degree of this influence varies among metals, and processes controlling metal distribution in this estuary appear to be more element-specific than spatially- or temporally-specific.

Selenastrum capricornutum Printz, growing in a chemically defined medium, was used as a model for studying adaptation of algae to a toxic metal (copper) ion. Cells exhibited lag-phase adaptation to 0.8 μM total Cu (10−12 M free ion concentration) after 20 generations of Cu exposure. Selenastrum adapted to the same concentration when Cu was gradually introduced over an 8-h period using a specially designed apparatus that provided a transient increase in exposure concentration. Cu adaptation was not attributable to media conditioning by algal exudates. Duration of lag phase was a more sensitive index of copper toxicity to Selenastrum that was growth rate or stationary-phase cell density under the experimental conditions used. Chemical speciation of the Cu dosing solution influenced the duration of lag phase even when media formulations were identical after dosing. Selenastrum initially exposed to Cu in a CuCl2 injection solution exhibited a lag phase of 3.9 d, but this was reduced to 1.5 d when a CuEDTA solution was used to achieve the same total Cu and EDTA concentrations. Physical and chemical processes that accelerated the rate of increase in cupric ion concentration generally increased the duration of lag phase.

Dissolved nutrient concentrations in natural waters may at times be controlled by interactions between particulate and solution phases. Effects of Zn [O-l PM total Zn(II)] and orthophosphate (8-12 PM total P) additions on growth indices for the chlorophyte Selenastrum capricornutum Printz were examined in a synthetic growth medium containing 50 mg liter-l colloidal titania. Over the Zn(H) concentration range used, detrimental growth and yield effects were observed. Addition of P to a synthetic growth medium (S-3) increased stationary phase cell density, but had minimal effect on growth rate and duration of lag phase. Presence of TiO, particles in culture media significantly reduced Zn and P dissolved fractions. Although adsorbed Zn and P were less available to Selenastrum, desorption of both solutes increased their availability. Rapid desorption of Zn(I1) from TiO, particles served in effect to buffer Zn2+ free ion concentration, until Zn became partitioned primarily with the algal fraction as cell concentration approached stationary phase density. Although phosphate desorption from TiO, in nonbiological systems was negligible, Sefenastrum was able to scavenge some P initially adsorbed onto TiO,. Accurate primary productivity predictions in nature may therefore require an understanding of equilibrium and reaction rates involved in the partitioning of nutrients and toxic substances between dissolved and particulate phases.

In unserem Fall von Sklerodermie, bei dem Schleimhautaffektion vorhanden war, gab es keine Hypercalcamie, aber eine Zunahme des Kalkgehaltes der Haut, und die Storungen der Kalkmobilisation wurde nachgewiesen, und durch Parathyreoidektomie wurde eine merkliche Besserung herbeigefuhrt. Besonderes Interesse gewinnt unser Fall durch die Kombination mit Leukamie. Die entfernte Nebenschilddruse wies Lipomatose auf, war 3–4mal so gros wie eine normale. Wir haben Grund, zu vermuten, das die Wirkungsweise der Parathyreoidektomie bei diesem Falle auf einen Stos auf den Calciumstoffwechsel zuruckzufuhren ist.

Nalorphine (150 μg/kg) and levallorphan (20 μg/kg), when administered to lightly anaesthetized subjects who had not received a narcotic, caused significant depression of respiratory rate and minute volume. In contrast, 5 and 10 μg/kg naloxone caused no respiratory depression. These doses of nalorphine, levallorphan, and naloxone caused a moderate decrease of pulse rate and systolic blood pressure. Naloxone 5 and 10 μg/kg offered significantly greater protection against the respiratory depressant effects of 20 μg/kg oxymorphone administered five minutes later than 150 μg/kg nalorphine or 20 μg/kg levallorphan. None of the three narcotic antagonists affected the oxymorphone-induced decrease of pulse rate, and all had about the same protective effect against the fall of systolic blood pressure caused by this compound. Since doses of naloxone, which provide significantly better protection against narcotic-induced respiratory depression than the conventional doses of nalorphine and levallorphan, cause no respiratory depression in themselves, it should be considered the narcotic antagonist of choice for clinical use.

On the basis of the Meksyn‐Stuart method, nonlinear instability of the plane Couette flow is investigated. The perturbed stream function and the mean flow field are determined by the Galerkin method. A neutral surface is obtained in a three‐dimensional space of the Reynolds number, wave‐number, and amplitude. The critical Reynolds number based on the width and the relative velocity is estimated to be about 190 000.