22 research outputs found

    Cerebrospinal fluid cannot be used to distinguish inflammatory myelitis from congestive myelopathy due to spinal dural arteriovenous fistula: case series.

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    Patients with congestive myelopathy due to spinal dural arteriovenous fistula (SDAVF) typically present with progressive sensory and motor disturbance in association with sphincter dysfunction. Spinal MRI usually shows longitudinally extensive T2 signal change. Here, we report four patients with progressive myelopathy due to SDAVF who also presented with findings on cerebrospinal fluid (CSF) examination suggestive of an inflammatory aetiology. Such CSF findings in SDAVF are important to recognise, to avoid the erroneous diagnosis of an inflammatory myelitis and inappropriate treatment with immunosuppression. SDAVF can be difficult to detect and may require repeated investigation, with formal angiography as the gold standard

    Antiphospholipid antibodies and neurological manifestations in acute COVID-19: A single-centre cross-sectional study

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    Background: A high prevalence of antiphospholipid antibodies has been reported in case series of patients with neurological manifestations and COVID-19; however, the pathogenicity of antiphospholipid antibodies in COVID-19 neurology remains unclear. Methods: This single-centre cross-sectional study included 106 adult patients: 30 hospitalised COVID-neurological cases, 47 non-neurological COVID-hospitalised controls, and 29 COVID-non-hospitalised controls, recruited between March and July 2020. We evaluated nine antiphospholipid antibodies: anticardiolipin antibodies [aCL] IgA, IgM, IgG; anti-beta-2 glycoprotein-1 [aβ2GPI] IgA, IgM, IgG; anti-phosphatidylserine/prothrombin [aPS/PT] IgM, IgG; and anti-domain I β2GPI (aD1β2GPI) IgG. Findings: There was a high prevalence of antiphospholipid antibodies in the COVID-neurological (73.3%) and non-neurological COVID-hospitalised controls (76.6%) in contrast to the COVID-non-hospitalised controls (48.2%). aPS/PT IgG titres were significantly higher in the COVID-neurological group compared to both control groups (p < 0.001). Moderate-high titre of aPS/PT IgG was found in 2 out of 3 (67%) patients with acute disseminated encephalomyelitis [ADEM]. aPS/PT IgG titres negatively correlated with oxygen requirement (FiO2 R=-0.15 p = 0.040) and was associated with venous thromboembolism (p = 0.043). In contrast, aCL IgA (p < 0.001) and IgG (p < 0.001) was associated with non-neurological COVID-hospitalised controls compared to the other groups and correlated positively with d-dimer and creatinine but negatively with FiO2. Interpretation: Our findings show that aPS/PT IgG is associated with COVID-19-associated ADEM. In contrast, aCL IgA and IgG are seen much more frequently in non-neurological hospitalised patients with COVID-19. Characterisation of antiphospholipid antibody persistence and potential longitudinal clinical impact are required to guide appropriate management

    Mechanism of Oxidation of Azide by Periodate in Acid Medium

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    104-10

    Oxidation of methionine by N-chloroacet-amide- Catalytic effect of formaldehyde

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    275-277Oxidation of -methionine(Met) by N-chloroacetamide (NCA) in buffered medium (pH ~ 7) in the presence and absence of formaldehyde is first order each in [NCAland [Met] and first order in [HCHO] when present. The observed rate constant shows a complex dependence on [H+]. The catalytic behaviour of HCHO could be explained by the fact that the rehybridization of sulphur atom from tetrahedral to trigonal bipyramidal structure is influenced by HCHO. The derived rate laws are consistent with the observed kinetics

    Sonochemical cyclopolymerization of diallylamine in the presence of peroxomonosulfate

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    The cyclopolymerization of a symmetrical nonconjugated diolefin, diallylamine (DA), initiated by peroxomonosulfate (PMS), proceeded only in the presence of ultrasound. The rate of polymerization showed a first-order dependence on DA and a half-order dependence on PMS concentration. The results are adequately explained through a proposed mechanism involving alternate intramolecular and intermolecular propagation reactions. The rate parameters for the cyclopolymerization are evaluated. The role of ultrasound in the initiation of cyclopolymerization is discussed

    Sonochemical cyclopolymerization of diallylamine

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    Cyclopolymerization of a symmetrical nonconjugated diolefin, diallylamine was found possible in the presence of ultrasound and peroxodisulphate. The rate of polymerization, R<SUB>p</SUB> showed first-and half-order dependencies on diallylamine and peroxodisulphate concentration, respectively. The results are explained through a proposed mechanism involving alternating intramolecular and intermolecular propagation reactions. The rate parameters for the cyclopolymerization are evaluated. The role of ultrasound in initiating the cyclopolymerization is discussed
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