Diphtheritic polyneuropathy : A clinical study and comparison with Guillain-Barré syndrome

Objectives and Methods - Clinical features of 50 adults with diphtheritic polyneuropathy (DP) were studied in Riga, Latvia and compared with 21 patients with Guillain-Barré syndrome (GBS). Results - Neurological complications occurred in 15% of patients admitted to hospital with diphtheria and usually after severe pharyngeal infection. Bulbar dysfunction occurred in 98% of patients with DP and only 10% of patients with GBS. Limb weakness was mild or absent in 30% of patients with DP. Ventilation dependent respiratory failure occurred in 20% of patients with DP. The first symptoms of DP occurred 2-50 days after the onset of local diphtheria infection. Neurological deterioration in DP continued for a median of 49 (range 15-83) days and improvement started 73 (range 20-115) days after onset. In 66% of patients with DP, the neuropathy was biphasic with a secondary worsening after 40 days. By contrast patients with GBS worsened for only 10 days on average (range 2-28 days) and improved after 21 (range 4-49) days. Eight patients with DP died, four from severe cardiomyopathy and four from multiple diphtheritic organ failure. Prolonged distal motor latencies (DMLs) were common to both DP and GBS, and more pronounced than motor conduction slowing. Limb symptoms continued after 1 year in 80% of the patients with DP, 6% were unable to walk independently, but independent respiratory and bulbar function had returned in all survivors. By comparison no patients with GBS died and none were severely disabled after 1 year. No death, in patients with DP occurred after antitoxin on days 1 or 2 after onset of diphtheria symptoms, whereas identical rates of death and peak severity of DP were seen both in those who received antitoxin on days 3-6 and those who did not receive it at all. Conclusion - Diphtheric polyneuropathy is much more likely than GBS to have a bulbar onset, to lead to respiratory failure, to evolve more slowly, to take a biphasic course, and to cause death or long term disability. Antitoxin seems ineffective if administered after the second day of diphtheritic symptoms.publishersversionPeer reviewe

Synchronous reluctance motors with fractional slot-concentrated windings

PhD ThesisToday, high efficiency and high torque density electrical machines are a growing research interest and machines that contain no permanent magnet material are increasingly sought. Despite the lack of interest over the last twenty years, the permanent magnet-free synchronous reluctance machine is undergoing a revival and has become a research focus due to its magnet-free construction, high efficiency and robustness. They are now considered a potential future technology for future industrial variable speed drive applications and even electric vehicles. This thesis presents for the first time a synchronous reluctance motor with fractional slot-concentrated windings, utilizing non-overlapping single tooth wound coils, for high efficiency and high torque density permanent magnet-free electric drives. It presents all stages of the design and validation process from the initial concept stage through the design of such a machine, to the test and validation of a constructed prototype motor. The prototype machine utilizes a segmented stator core back iron arrangement for ease of winding and facilitating high slot fill factors. The conventional synchronous reluctance motor topology utilizes distributed winding systems with a large number of stator slots, presenting some limitations and challenges when considering high efficiency, high torque density electrical machines with low cost. This thesis aims to present an advancement in synchronous reluctance technology by identifying limitations and improving the design of synchronous reluctance motors through development of a novel machine topology. With the presented novel fractional slot concentrated winding machine design, additional challenges such as high torque ripple and low power factor arise, they are explored and analysed - the design modified to minimise any unwanted parasitic effects. The electrical and electromagnetic characteristics of the developed machine are also explored and compared with that of a conventional machine. A novel FEA post-processing technique is developed to analyse individual air-gap field harmonic torque contributions and the machines dq theory also modified in order to account for additional effects. The developed machine is found to be lower cost, lower mass and higher efficiency than an equivalent induction or conventional synchronous reluctance motor, but does suffer higher torque ripples and lower power factor. The prototype is validated using static and dynamic testing with the results showing a good match with finite element predictions. The work contained within this thesis can be considered as a first step to developing commercial technology based on the concept for variable speed drive applications.Financial assistance was provided by was provided by the UK Engineering and Physical Sciences Research Council (EPSRC) in the form of a Doctoral Training Award and additional financial assistance was kindly provided by Cummins Generator Technologies, Stamford, UK, through industrial sponsorship of this wor

Studies in benzimidazo [2,1-a] isoquinoline chemistry

Studies in Benzimidazo[2,1-a]isoquinoline Chemistry by Michael John Donaghy B. Sc. (Hons.) Ellipticine, a member of the pyrido[4,3-b]carbazole alkaloid family first isolated in 1959 from the leaves of the plant Ochrosia Elliptica has been shown to possess anti-cancer activity against various tumours. Ellipticine is thought to undergo biological oxidation to give the more active 9-hydroxyellipticine that is subsequently converted to a highly reactive quinone-imine intermediate. The quinone-imine is then thought to interact with bionucleophiles in the body promoting cell death. The aim of the project was to synthesise a series of benzimidazo[2,1-a]isoquinolines. The benzimidazo[2,1-c]isoquinolines were similar in general structure to ellipticines and should therefore undergo similar biological reactions. The target benzimidazo[2,1-a]isoquinolines have been screened to evaluate their ability to inhibit the enzyme topoisomerase II that is involved in DNA replication and ultimately cell reproduction. The target compounds have also been evaluated by the American National Cancer Institute

Basketball New Zealand infographic: return to training 50-30-20-10 rule [for basketball players]

Infographic outlines the return to training 50-30-20-10 rule for basketball players

Basketball New Zealand infographic: recovery benefits

Infographic outlines the key benefits of recovery for basketball players

Stratigraphy, age, and provenance of the Eocene Chumstick basin, Washington Cascades; implications for paleogeography, regional tectonics, and development of strike-slip basins: Reply

We welcome the comment by Evans (2022) and the opportunity to further discuss our study of the Chumstick Formation. The correlation of fault-bound nonmarine sedimentary units in central and western Washington has been a topic of interest, and debate, for many years (Frizzell, 1979; Taylor et al., 1988; Gresens et al., 1981; Gresens, 1983; Evans and Johnson, 1989; Evans, 1994; Cheney and Hayman, 2009). However, many questions about the regional correlation of these units were resolved with the publication of a suite of internally consistent high-precision 206Pb/238U zircon dates from volcanic interbeds throughout the early to middle Eocene stratigraphy (Eddy et al., 2016). This data set confirmed the timing of sediment deposition of the different members within the Chumstick Formation. Donaghy et al. (2021) provides a detailed study of the Chumstick Formation, which builds on earlier research by Gresens et al. (1981, 1983), McClincy (1986), and Evans (1994) by incorporating new geochronologic information and additional clast counts, detrital zircon geochronology, and facies mapping. We interpret large parts of the Chumstick Formation to represent a spatially and temporally distinct sedimentary system between the Leavenworth and Entiat fault zones that likely formed as a pull-apart basin. Evans (2022) objects to several of the interpretations presented in Donaghy et al. (2021) regarding the relationship between different members of the Chumstick Formation and surrounding sedimentary units, the timing of strike-slip faulting, and the regional tectonic setting of these rocks. We discuss each of these points in the following sections

White matter abnormalities in methcathinone abusers with an extrapyramidal syndrome

Funding Information: National Institute for Health Research Oxford Biomedical Research Centre (to H.J.B. and C.J.S.); the Wellcome Trust (to H.J.B.) and the European Social Fund (to A.S.). Copyright: Copyright 2017 Elsevier B.V., All rights reserved.We examined white matter abnormalities in patients with a distinctive extrapyramidal syndrome due to intravenous methcathinone (ephedrone) abuse. We performed diffusion tensor imaging in 10 patients and 15 age-matched controls to assess white matter structure across the whole brain. Diffuse significant decreases in white matter fractional anisotropy, a diffusion tensor imaging metric reflecting microstructural integrity, occurred in patients compared with controls. In addition, we identified two foci of severe white matter abnormality underlying the right ventral premotor cortex and the medial frontal cortex, two cortical regions involved in higher-level executive control of motor function. Paths connecting different cortical regions with the globus pallidus, the nucleus previously shown to be abnormal on structural imaging in these patients, were generated using probabilistic tractography. The fractional anisotropy within all these tracts was lower in the patient group than in controls. Finally, we tested for a relationship between white matter integrity and clinical outcome. We identified a region within the left corticospinal tract in which lower fractional anisotropy was associated with greater functional deficit, but this region did not show reduced fractional anisotropy in the overall patient group compared to controls. These patients have widespread white matter damage with greatest severity of damage underlying executive motor areas.Peer reviewe

Grey matter abnormalities in methcathinone abusers with a Parkinsonian syndrome

Funding Information: The study was supported by Grants GARNR9199 and GARLA0148P of the Estonian Science Foundation, and Grant No. 5.8.2 of the National Research Program of Latvia. Ricarda A L Menke is employed by the University of Oxford and her salary is funded by the Medical Research Council of the UK. Heidi Johansen-Berg is employed by the Universities of Oxford and Oslo, holds grants from the Wellcome Trust, National Institutes of Health Research, Education Endowment Foundation, Stroke Association, and Royalties from Elsevier. Charlotte J Stagg holds a Sir Henry Dale Fellowship jointly funded by the Wellcome Trust and the Royal Society. Ain?rs Stepens holds Grant No. 5.8.2 of the National Research Program of Latvia, which supported this study. Pille Taba holds Grant 9199 of the Estonian Science Foundation, which supported this study, is principal investigator of Grant 3.2.1001.11-0017 of the EU European Regional Development Fund, and participates in Grant IUT2-4 of the Estonian Research Council. Publisher Copyright: © 2016 The Authors. Brain and Behavior published by Wiley Periodicals, Inc. Copyright: Copyright 2018 Elsevier B.V., All rights reserved.Background: A permanent Parkinsonian syndrome occurs in intravenous abusers of the designer psychostimulant methcathinone (ephedrone). It is attributed to deposition of contaminant manganese, as reflected by characteristic globus pallidus hyperintensity on T1-weighted MRI. Methods: We have investigated brain structure and function in methcathinone abusers (n = 12) compared to matched control subjects (n = 12) using T1-weighted structural and resting-state functional MRI. Results: Segmentation analysis revealed significant (p <.05) subcortical grey matter atrophy in methcathinone abusers within putamen and thalamus bilaterally, and the left caudate nucleus. The volume of the caudate nuclei correlated inversely with duration of methcathinone abuse. Voxel-based morphometry showed patients to have significant grey matter loss (p <.05) bilaterally in the putamina and caudate nucleus. Surface-based analysis demonstrated nine clusters of cerebral cortical thinning in methcathinone abusers, with relative sparing of prefrontal, parieto-occipital, and temporal regions. Resting-state functional MRI analysis showed increased functional connectivity within the motor network of patients (p <.05), particularly within the right primary motor cortex. Conclusion: Taken together, these results suggest that the manganese exposure associated with prolonged methcathinone abuse results in widespread structural and functional changes affecting both subcortical and cortical grey matter and their connections. Underlying the distinctive movement disorder caused by methcathinone abuse, there is a more widespread pattern of brain involvement than is evident from the hyperintensity restricted to the basal ganglia as shown by T1-weighted structural MRI.Peer reviewe