303 research outputs found
\u3cem\u3eBecoming a Subject: Political Prisoners During the Greek Civil War\u3c/em\u3e, by Polymeris Voglis
No full textReviews the non-fiction book Becoming a Subject: Political Prisoners During the Greek Civil War, by Polymeris Voglis
Fatal intracranial haemorrhage occurring after oral anticoagulant treatment initiation for secondary stroke prevention in patients with atrial fibrillation.
No full textBACKGROUND AND PURPOSE
In this pooled analysis of seven multicentre cohorts potential differences were investigated in the incidence, characteristics and outcomes between intracranial haemorrhages (ICHs) associated with the use of non-vitamin K antagonist oral anticoagulants (NOAC-ICH) or with vitamin K antagonists (VKA-ICH) in ischaemic stroke patients after oral anticoagulant treatment initiation for atrial fibrillation (AF).
METHODS
Data from 4912 eligible AF patients who were admitted in a stroke unit with ischaemic stroke or transient ischaemic attack and who were treated with either VKAs or NOACs within 3 months post-stroke were included. Fatal ICH was defined as death occurring during the first 30 days after ICH onset. A meta-analysis of available observational studies reporting 30-day mortality rates from NOAC-ICH or VKA-ICH onset was additionally performed.
RESULTS
During 5970 patient-years of follow-up 71 participants had an ICH, of whom 20 were NOAC-ICH and 51 VKA-ICH. Patients in the two groups had comparable baseline characteristics, except for the higher prevalence of kidney disease in VKA-ICH patients. There was a non-significant higher number of fatal ICH in patients with VKAs (11 events per 3385 patient-years) than in those with NOACs (three events per 2623 patient-years; hazard ratio 0.32, 95% confidence interval 0.09-1.14). Three-month functional outcomes were similar (P > 0.2) in the two groups. The meta-analysis showed a lower 30-day mortality risk for patients with NOAC-ICH compared to VKA-ICH (relative risk 0.70, 95% confidence interval 0.51-0.95).
CONCLUSIONS
Non-vitamin K oral anticoagulants for intracranial haemorrhages and VKA-ICH occurring during secondary stroke prevention of AF patients have comparable baseline characteristics and outcomes except for the risk of fatal ICH within 30 days, which might be greater in VKA-ICH
Georgios Polymeris: a well-educated printer from Epirus (1811?-1858?) (Τίτλος περίληψης)
No full textσ. [385]-[413]Περιέχει παράρτημα με κατάλογο των εκδόσεων της Τυπογραφίας Γ. ΠολυμέρηΚείμενο στα ελληνικά με περίληψη στα αγγλικά με τον τίτλο: Georgios Polymeris: a well-educated printer from Epirus (1811?-1858?)Georgios Polymeres was one of the many Greek children, who arrived in America during the period of the Greek Revolution (1821). Like the other children he studied there under the care of philhellen citizens or religious associations. When Georgios Polymeres returned to Greece, he opened his own printing office, which operated mainly in Ermoupolis on the island of Syra. At the same time. Polymeris translated and wrote various works. However, the information available up to now about this scholar, who worked during the reign of King Othon, is incomplete.
This particular study has been based on unpublished material found in the archives, the Publications by Polymeres and also his own writings. It throws light upon the unknown facts of his life (his age, where his parents came from, where he was bom, the possible date of his return to Greece, the possible date of his death). Moreover, it presents a picture of how the above mentioned typography operated. Finally, this study endeavours to show the influence his stay in America had on him as well as his study of the works of Korais on the one hand and his intrest in educational, social, political issues of his time on the other hand. This particular study has attempted to bring to light the personality of Polymeres. Perhaps it will stimulate further studies concerning especially his arrival and his stay in Boston, America.ΒιογραφικάΗ "Τυπογραφία Γεωργίου Πολυμέρη" - Ο θάνατοςΟι εκδόσεις της Τυπογραφίας Γ. ΠολυμέρηΤο συγγραφικό έργο του Γ. ΠολυμέρηΗ ΑυτομάθειαΟι Διατριβές για το μονοπώλιο στα διδακτικά βιβλίαΤα εγχειρίδια ΑγγλικήςΕπιστολή πολιτικήΠεριήγησις εν ΚριμαίαΠαράρτημαΔωδώνη: Τεύχος Πρώτο: επιστημονική επετηρίδα του Τμήματος Ιστορίας και Αρχαιολογίας της Φιλοσοφικής Σχολής του Πανεπιστημίου Ιωαννίνων; Τόμ. 21 (1992
Impact of body mass index on outcome in stroke patients treated with intravenous thrombolysis.
No full textBACKGROUND AND PURPOSE
The impact of body mass index (BMI) on outcome in stroke patients treated with intravenous thrombolysis (IVT) was investigated.
METHODS
In a multicentre IVT-register-based observational study, BMI with (i) poor 3-month outcome (i.e. modified Rankin Scale scores 3-6), (ii) death and (iii) symptomatic intracranial haemorrhage (sICH) based on criteria of the ECASS II trial was compared. BMI was used as a continuous and categorical variable distinguishing normal weight (reference group 18.5-24.9 kg/m(2) ) from underweight (<18.5 kg/m(2) ), overweight (25-29.9 kg/m(2) ) and obese (≥30 kg/m(2) ) patients. Univariable and multivariable regression analyses with adjustments for age and stroke severity were done and odds ratios with 95% confidence intervals [OR (95% CI)] were calculated.
RESULTS
Of 1798 patients, 730 (40.6%) were normal weight, 55 (3.1%) were underweight, 717 (39.9%) overweight and 295 (16.4%) obese. Poor outcome occurred in 38.1% of normal weight patients and did not differ significantly from underweight (45.5%), overweight (36.1%) and obese (32.5%) patients. The same was true for death (9.5% vs. 14.5%, 9.6% and 7.5%) and sICH (3.9% vs. 5.5%, 4.3%, 2.7%). Neither in univariable nor in multivariable analyses did the risks of poor outcome, death or sICH differ significantly between BMI groups. BMI as a continuous variable was not associated with poor outcome, death or sICH in unadjusted [OR (95% CI) 0.99 (0.97-1.01), 0.98 (0.95-1.02), 0.98 (0.94-1.04)] or adjusted analyses [OR (95% CI) 1.01 (0.98-1.03), 0.99 (0.95-1.05), 1.01 (0.97-1.05)], respectively.
CONCLUSION
In this largest study to date, investigating the impact of BMI in IVT-treated stroke patients, BMI had no prognostic meaning with regard to 3-month functional outcome, death or occurrence of sICH
A rare case of poorly differentiated mixed neuroendocrine-nonneuroendocrine tumor of the caecum with long term survival: A case report
No full textA 59-year-old woman presented with flushing attacks accompanied by tachycardia and hypotension, which lasted approximately 30 to 60 minutes, underwent 18 years ago a gastrointestinal tumor resection. The histologic examination revealed a poorly differentiated mixed neuroendocrine/adenocarcinoma located in the caecum with regional metastases. Postoperatively, the patient received combined chemotherapy of 5-fluorouracil with interferon for six months and since has remained asymptomatic. Her examination revealed positivity for chromogranin A (CgA) and a-Fetoprotein (aFP) (580 ng/24 h, normal range 27-94, and 10 IU/mL, normal range 0-6, respectively). Urinary 5-hydroxy indole acetic acid excretion was remarkably high (41.8 mg/24 h, normal range 2-10 mg/24 h). An abdominal Magnetic Resonance Imaging scan revealed multiple focal loci in the liver whose histological examination revealed a carcinoid tumor confirmed by an Octreoscan. Additional uptake was noted on the right shoulder and the right sternum-clavicle joint confirmed by Tc-99m MDP scan. The patient received somatostatin analogue therapy followed by long-acting release octreotide analogue therapy (30 mg/month) showing a partial improvement of relevant biomarkers. Two years later, carcinoid syndrome symptoms reappeared and due to the tumors expression of somatostatin receptors the patient received peptide receptor radionuclide therapy with 177Lu-DOTATATE that resulted in both clinical and biochemical improvements. © 2022 Antonis Polymeris et al., published by Sciendo
Thermoluminescence and optically stimulated luminescence properties of natural barytes
No full textGeorge S. Polymeris is indebted to TUBITAK (The Scientific and Technological Research Council of Turkey) for financial support.Heavy, baryte-loaded, concrete is commonly used as radiation shielding material around high energy particle accelerators. Concrete samples received from a shielding block located at CERN cite contain many crystalline inclusions which were identified as barytes by X-ray diffraction analysis and separated by their color, classified as white, orange and green. Basic properties of thermoluminescence (TL) and optically stimulated luminescence (OSL) signals of these barytes samples such as thermal and optical stability, repeatability and mainly the linearity of both their luminescence responses were investigated as a function of beta dose These results are also discussed regarding detailed investigation on the correlation between TL and OSL signals and their implications for retrospective dosimetryTürkiye Bilimsel ve Teknolojik Araştırma Kurumu (TÜBİTAK)Publisher's Versio
Analysis probes and statistical parameters affecting the OSL ages of mortar samples; a case study from Italy
No full textMortars stand among the very few materials that theoretically cannot be reused due to irreversible hardening processes. Among the various dating techniques, radiocarbon and Optically Stimulated Luminescence (OSL) struggle for being selected as the most robust and reliable dating technique for the specific material. The principle of mortar OSL dating depends on the bleaching of the quartz grains of the sandy aggregate while mixing and laying the mortar to daylight. Thus, the OSL ages strongly depend on the effective bleaching of the quartz. Here, we deal with OSL ages from the old Roman Theatre of Padua. Preliminary OSL results based on Single Aliquot Regeneration (SAR) protocol using three regenerated doses to multigrain (MG) quartz aliquots, indicated distributions of ED (Equivalent Dose) leading to significant mismatch of these results compared to the expected ages. The present work attempts to discuss the influence of various data analysis approaches such as (a) exclusion criteria like recycling ratio and recuperation values, (b) selection of the suitable region of interest in the signal's integral along with the correct background (late or early) subtraction technique and (c) appropriate statistical analysis by selecting the suitable age model (descriptive statistics, Central Age Model, Minimum Age Model) on the final distribution as well as both value and precision of the ED, enabling thus to obtain ages that are not only more accurate, but also closer to what was expected. Alternative statistical indicators of either the symmetry of the ED distributions (like skewness, kurtosis, etc) or the OSL signal itself (residual distribution analysis, kinetic parameters and percentage contribution of each OSL component to the overall signal) will be assessed in an effort to investigate possible correlations
Insights on the firing temperature of ancient ceramic coffins through a multi-analytical approach: The case of the Sada Nishizuka Kofun, Japan
No full textInvestigating the heating temperatures of ancient ceramic artifacts can offer information about their production technology and enrich our knowledge about the fire control skills in ancient times. We present here the results of a multi-analytical approach, including magnetic, X-Ray Powder Diffraction (XRPD) and thermoluminescence (TL) analyses, applied on the investigation of the equivalent firing temperature of the ceramic coffin (No 2) found in the well-known Sada Nishizuka Kofun, Japan. Monitoring of the magnetic properties of the studied fragments versus laboratory heating showed clear magnetic enhancement at relatively low temperatures around 350-500 degrees C. The magnetic results were compared with independent data obtained from XRPD and TL analyses. The XRPD patterns showed the presence of quartz, plagioclases and clay minerals such as muscovite and smectite, which indicate firing temperatures lower than 850-950 degrees C. The presence of kaolinite in almost all the studied samples lower the estimate temperature below 550 degrees C. Such data were further confirmed by the TL analysis which suggest firing temperature lower than 525 degrees C. The results obtained indicate that the coffin was most probably produced in an open or covered kiln, following the Japanese Haji-type traditional production, reaching maximum firing temperature lower than 550 degrees C. This study offers the first archaeometric experimental data to better understand the production strategy of ceramic coffins during the Kofun period in Japan and highlights the potential of non-conventional archaeometric analyses, such as magnetic and thermoluminescence investigations, to obtain information on firing procedures for ancient ceramic artifacts. (c) 2023 Consiglio Nazionale delle Ricerche (CNR). Published by Elsevier Masson SAS. All rights reserved
Stroke, atrial fibrillation, and the management of oral anticoagulation
No full textAtrial fibrillation (AF) is the most common arrhythmia, becomes more prevalent with increasing age and is linked to neurological complications, including most notably ischemic stroke, but also cognitive dysfunction. The recent introduction of direct oral anticoagulants (DOAC) significantly advanced the management of patients with AF. Large-scale randomized controlled trials showed that – for most patients – DOAC are at least as effective as vitamin K antagonists (VKA) in preventing ischemic stroke but have the advantage of a lower risk for intracranial hemorrhage (ICH). However, clinically important patient populations were underrepresented or excluded in these trials, and more refined aspects which are important in clinical practice, including concomitant stroke etiologies or brain pathologies, medication adherence, neuroimaging characteristics or biomarker signatures were not addressed. Therefore, several research gaps and challenges remained for neurologists treating patients with AF, of which we selected 4 aspects to focus on in the following topics that comprise this PhD thesis.
The first topic focused on 3 high-risk subgroups of patients with AF treated with oral anticoagulants who were underrepresented or excluded from the large randomized trials. These were (i) stroke patients aged 85 years and older (“the oldest-old”), (ii) severely affected stroke patients dependent on the daily help of others, and (iii) stroke patients with concomitant cerebral small vessel disease. In the first main project of this PhD thesis we examined the performance of DOAC versus VKA in the oldest-old patients with recent stroke and AF in a large pooled analysis across 7 cohort studies. Facing the paucity of randomized evidence, many physicians have been reluctant to use DOAC in these patients. With this project, we provided new evidence that the benefits of DOAC over VKA are preserved in the oldest old with recent stroke, without any signal of a safety concern regarding risk of ICH. In an additional project from our local cohort, we showed that the favourable profile of DOAC over VKA was preserved also among patients with AF and recent stroke who were dependent on the daily help of others, a patient subgroup for which no data existed previously. Finally, we showed in the same cohort that concomitant cerebral small vessel disease in anticoagulated patients with AF and recent stroke was associated with an unfavorable clinical course, but the risk for ischemic stroke remained higher than the risk for ICH, even in the presence of small vessel disease. The latter two projects fall within the scope of this PhD thesis, but do not constitute its main body. Although both manuscripts were published in peer-reviewed journals, for the purpose of this thesis their presentation is restricted to abstracts. Our findings in the first topic of this PhD thesis advance the evidence for the use of anticoagulants in high-risk patient subgroups with AF and recent stroke.
The second topic examined ischemic stroke occurring despite anticoagulant therapy in AF patients. With the increasing use of oral anticoagulants, this scenario represents a growing challenge in everyday clinical practice, indicating the need to elucidate the underlying causes and – based on these – the optimal subsequent management strategies. We addressed this issue in the second main project of this PhD thesis in a large retrospective analysis pooling data of prospectively collected patients from 11 stroke centers. We found that the causes of stroke despite anticoagulation in AF patients were heterogeneous, but form three main clusters, all of which were comparably important. These included (i) competing stroke mechanisms other than AF-related cardioembolism, and (ii) insufficient anticoagulation due to prescription errors and nonadherence, suggesting that individualized treatment approaches to address these causes are necessary. Importantly, the third and most common cause was AF-related cardioembolism despite sufficient anticoagulation, indicating the need to develop novel preventive strategies beyond the currently available anticoagulants. Furthermore, in this project we were able to demonstrate that AF patients with stroke despite anticoagulation represent a high-risk patient population, with higher than expected rates of stroke recurrence and other unfavorable outcomes. Finally, we showed also in this population that subsequent treatment with DOAC was associated with better outcomes than VKA treatment. Interestingly, neither any specific switch between DOAC nor antiplatelets as add-on treatment to anticoagulation seemed to confer any benefit, although both approaches are often employed in clinical practice. This study advanced the evidence for the preferential use of DOAC over VKA in AF patients with stroke despite anticoagulation, for whom no data existed so far, while demonstrating the need for more individualized and novel treatment approaches in these high-risk patients.
The third topic of this PhD thesis was the adherence of stroke patients to DOAC. Unlike VKA, DOAC require no coagulation monitoring and have short half-lives, which has raised concerns about nonadherence in AF patients treated with DOAC. This is particularly pertinent to patients with stroke, as shown in the second topic of this PhD thesis. In order to examine the medication-taking behaviour and the effect of an adherence-enhancing intervention in patients with recent stroke, we designed, initiated, and undertook the MAAESTRO study. MAAESTRO has been a joint venture with the Pharmaceutical Care Research Group of the University of Basel and has used electronic monitoring as the main method to assess adherence, data on which have been scarce so far. MAAESTRO comprises an initial observational phase and a subsequent randomized controlled interventional phase. MAAESTRO successfully concluded recruitment in July 2021 with reaching the predefined goal of n=130 participants. The observational study phase has now been completed, but as follow-up in the interventional phase is ongoing, the main study results are not part of this PhD thesis. Still, we present the published study protocol and the first results from the observational phase on the patterns of DOAC-taking behaviour, as well as an exploratory analysis on how adherence was impacted by the COVID-19 lockdown as abstracts, as these publications fall within the scope of this PhD thesis, but do not formally constitute its main body.
The fourth and final topic of this PhD thesis focused on cognitive dysfunction as a neurological complication of AF. While stroke is a well-known consequence of AF, there is increasing evidence that AF is also linked to cognitive dysfunction independent of ischemic stroke, but the mechanisms underlying this association are unclear. To preserve cognitive function in the growing population of elderly AF patients, a better understanding of these mechanisms is needed. Using data from the multicenter Swiss-AF Cohort Study, in the third main project of this PhD thesis we investigated serum neurofilament light chain (sNfL), a novel blood-based biomarker of neuronal damage, as a tool to explore the mechanisms through which neurological disease occurs in AF. In a cross-sectional analysis, we showed that sNfL is inversely associated with brain volume and cognitive function, thereby demonstrating that it represents a relevant biomarker of brain health in AF patients. Furthermore, we showed that neuronal loss measured by sNfL is associated with age, diabetes mellitus, heart failure, blood pressure and vascular brain lesions, observations which provide mechanistic insights into the occurrence of neurological disease in AF. Finally, in the fourth main project of this PhD thesis, we additionally investigated in this elderly cardiovascular cohort how renal function and body mass index contribute to sNfL levels in order to gain insights into the homeostasis (i.e., clearance and distribution) of this biomarker in the blood compartment. A better understanding of this is necessary towards further establishing this neurological biomarker in cardiovascular and dementia research. We showed that both renal function and body mass index were strongly, inversely associated with sNfL, but only renal function explained a relevant proportion of its variance. With this project we provided evidence for the importance of accounting for renal function in future sNfL-based investigations in elderly cardiovascular populations, in whom chronic kidney disease is highly prevalent
ESO888016 Supplementary material - Supplemental material for Small vessel disease is associated with an unfavourable outcome in stroke patients on oral anticoagulation
No full textSupplemental material, ESO888016 Supplementary material for Small vessel disease is associated with an unfavourable outcome in stroke patients on oral anticoagulation by Lisa Hert, Alexandros A. Polymeris, Sabine Schaedelin, Johanna Lieb, David J. Seiffge, Christopher Traenka, Joachim Fladt, Sebastian Thilemann, Henrik Gensicke, Gian Marco De Marchis, Leo Bonati, Philippe Lyrer, Stefan T. Engelter and Nils Peters in European Stroke Journal</p
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