EFFECT OF NICORANDIL ON PENTYLENETETRAZOLE (PTZ) INDUCED CONVULSIONS IN MICE

Aims & Objectives: To evaluate or screen the anticonvulsant effect of Nicorandil a potassium channel opener in Pentylenetetrazole(PTZ) induced convusions in albino mice. Materials & Methods: Mice of either sex weighing 20-25gms were selected for the present study. The animals were divided into 6 groups with each group consisting of 6 albino mice. Group 1 mice received placebo (0.2ml of distilled water) intraperitoneally (i.p), group 2 received sodium valproate 200 mg/kg/i.p. as positive control, while groups 3,4, 5 and 6 were administered Nicorandil 5, 10, 20 and 40 mg/kg i.p respectively. Pentylenetetrazole (PTZ) was administered in the dose of 100mg/kg i.p, 30mins after Nicorandil/ control drug pre-treatment. Onset and duration of clonic convulsion were recorded. Results: Nicorandil pretreatment in the dose of 5mg/kg increased onset time and significantly decreased the duration of convulsions,while the doses of 10, 20, 40mg/kg prevented the convulsions. Conclusion: Nicorandil possesses significant anticonvulsant activity comparable to sodium valproate on PTZ induced seizure in albino mice. KEYWORDS: Pentylenetetrazole; Sodium valproate; Nicorandil; Anticonvulsant activity

EFFECT OF NICORANDIL ON PENTYLENETETRAZOLE (PTZ) INDUCED CONVULSIONS IN MICE

Aims & Objectives: To evaluate or screen the anticonvulsant effect of Nicorandil a potassium channel opener in Pentylenetetrazole(PTZ) induced convusions in albino mice. Materials & Methods: Mice of either sex weighing 20-25gms were selected for the present study. The animals were divided into 6 groups with each group consisting of 6 albino mice. Group 1 mice received placebo (0.2ml of distilled water) intraperitoneally (i.p), group 2 received sodium valproate 200 mg/kg/i.p. as positive control, while groups 3,4, 5 and 6 were administered Nicorandil 5, 10, 20 and 40 mg/kg i.p respectively. Pentylenetetrazole (PTZ) was administered in the dose of 100mg/kg i.p, 30mins after Nicorandil/ control drug pre-treatment. Onset and duration of clonic convulsion were recorded. Results: Nicorandil pretreatment in the dose of 5mg/kg increased onset time and significantly decreased the duration of convulsions,while the doses of 10, 20, 40mg/kg prevented the convulsions. Conclusion: Nicorandil possesses significant anticonvulsant activity comparable to sodium valproate on PTZ induced seizure in albino mice. KEYWORDS: Pentylenetetrazole; Sodium valproate; Nicorandil; Anticonvulsant activity

Neurite Orientation Dispersion and Density Imaging Color Maps to Characterize Brain Diffusion in Neurologic Disorders

Purpose: Neurite orientation dispersion and density imaging (NODDI) has recently been developed to overcome diffusion technique limitations in modeling biological systems. This manuscript reports a preliminary investigation into the use of a single color-coded map to represent NODDI-derived information. Materials and methods: An optimized diffusion-weighted imaging protocol was acquired in several clinical neurological contexts including demyelinating disease, neoplastic process, stroke, and toxic/metabolic disease. The NODDI model was fitted to the diffusion datasets. NODDI is based on a three-compartment diffusion model and provides maps that quantify the contributions to the total diffusion signal in each voxel. The NODDI compartment maps were combined into a single 4-dimensional volume visualized as RGB image (red for anisotropic Gaussian diffusion, green for non-Gaussian anisotropic diffusion, and blue for isotropic Gaussian diffusion), in which the relative contributions of the different microstructural compartments can be easily appreciated. Results: The NODDI color maps better describe the heterogeneity of neoplastic as well inflammatory lesions by identifying different tissue components within areas apparently homogeneous on conventional imaging. Moreover, NODDI color maps seem to be useful for identifying vasogenic edema differently from tumor-infiltrated edema. In multiple sclerosis, the NODDI color maps enable a visual assessment of the underlying microstructural changes, possibly highlighting an increased inflammatory component, within lesions and potentially in normal-appearing white matter. Conclusion: The NODDI color maps could make this technique valuable in a clinical setting, providing comprehensive and accessible information in normal and pathological brain tissues in different neurological pathologies

Personal protective equipment (PPE) related adverse skin reactions among healthcare workers at the main COVID-19 isolation center in Barbados

Background: The use of personal protective equipment (PPE) reduces the risk of transmission of infectious agents significantly among healthcare workers (HCWs). The study aimed to investigate the prevalence and characteristics of PPE-related adverse skin reactions among HCWs working at the main COVID-19 isolation center in Barbados. Methods: A cross-sectional web-based online survey was conducted during April to June 2021 which recorded demographic information, details of PPE use and adverse skin reactions including severity and duration of onset of symptoms. Results: Most of the respondents used PPE for consecutive days (77.9%), 1–6 h/day (59.2%), and more than a year (62.5%). Fewer than half of the participants (45.6%) experienced adverse skin reactions from the use of PPE. The reactions were mostly observed in the cheeks (40.4%) and nose bridges (35.6%). Females had more reactions than their male counterparts (p = 0.003). The use of N95 masks and a combination of surgical and N95 masks produced adverse effects predominantly in the ears (60%) and cheeks (56.4%). Binary logistic regression showed that female HCWs (OR = 5.720 95% CI: 1.631, 20.063), doctors (OR = 5.215 95% CI: 0.877, 31.002), and longer duration of PPE use (>1 year) (OR = 2.902 95% CI: 0.958, 8.787) caused a significantly higher prevalence of adverse skin reactions. Conclusion: The PPE-related skin reactions were common among HCWs which mainly occurred due to prolonged use. Preventive measures inclusive of appropriate training of HCWs on the use of PPE are recommended to minimize these adverse event

Penumbral imaging and functional outcome in patients with anterior circulation ischaemic stroke treated with endovascular thrombectomy versus medical therapy: a meta-analysis of individual patient-level data

Background: CT perfusion (CTP) and diffusion or perfusion MRI might assist patient selection for endovascular thrombectomy. We aimed to establish whether imaging assessments of irreversibly injured ischaemic core and potentially salvageable penumbra volumes were associated with functional outcome and whether they interacted with the treatment effect of endovascular thrombectomy on functional outcome. Methods: In this systematic review and meta-analysis, the HERMES collaboration pooled patient-level data from all randomised controlled trials that compared endovascular thrombectomy (predominantly using stent retrievers) with standard medical therapy in patients with anterior circulation ischaemic stroke, published in PubMed from Jan 1, 2010, to May 31, 2017. The primary endpoint was functional outcome, assessed by the modified Rankin Scale (mRS) at 90 days after stroke. Ischaemic core was estimated, before treatment with either endovascular thrombectomy or standard medical therapy, by CTP as relative cerebral blood flow less than 30% of normal brain blood flow or by MRI as an apparent diffusion coefficient less than 620 μm2/s. Critically hypoperfused tissue was estimated as the volume of tissue with a CTP time to maximum longer than 6 s. Mismatch volume (ie, the estimated penumbral volume) was calculated as critically hypoperfused tissue volume minus ischaemic core volume. The association of ischaemic core and penumbral volumes with 90-day mRS score was analysed with multivariable logistic regression (functional independence, defined as mRS score 0–2) and ordinal logistic regression (functional improvement by at least one mRS category) in all patients and in a subset of those with more than 50% endovascular reperfusion, adjusted for baseline prognostic variables. The meta-analysis was prospectively designed by the HERMES executive committee, but not registered. Findings: We identified seven studies with 1764 patients, all of which were included in the meta-analysis. CTP was available and assessable for 591 (34%) patients and diffusion MRI for 309 (18%) patients. Functional independence was worse in patients who had CTP versus those who had diffusion MRI, after adjustment for ischaemic core volume (odds ratio [OR] 0·47 [95% CI 0·30–0·72], p=0·0007), so the imaging modalities were not pooled. Increasing ischaemic core volume was associated with reduced likelihood of functional independence (CTP OR 0·77 [0·69–0·86] per 10 mL, pinteraction=0·29; diffusion MRI OR 0·87 [0·81–0·94] per 10 mL, pinteraction=0·94). Mismatch volume, examined only in the CTP group because of the small numbers of patients who had perfusion MRI, was not associated with either functional independence or functional improvement. In patients with CTP with more than 50% endovascular reperfusion (n=186), age, ischaemic core volume, and imaging-to-reperfusion time were independently associated with functional improvement. Risk of bias between studies was generally low. Interpretation: Estimated ischaemic core volume was independently associated with functional independence and functional improvement but did not modify the treatment benefit of endovascular thrombectomy over standard medical therapy for improved functional outcome. Combining ischaemic core volume with age and expected imaging-to-reperfusion time will improve assessment of prognosis and might inform endovascular thrombectomy treatment decisions. Funding: Medtronic