98 research outputs found

    There is no consensus on the myocardial ischemia/reperfusion injury induction methods in animal studies

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    Dear Editor: Ischemic heart diseases (IHDs) are among the most important causes of death and disability worldwide. Every year, 10.6 million people are diagnosed with IHDs; in 2017, 8.9 million died due to this disease (1). The treatment of myocardial infarction is principally based on prompt blood supply restoration to salvage the ischemic tissue utilizing timely thrombolytic medications and coronary revascularization (2). However, the subsequent reperfusion provokes secondary cellular damage, broadly referred to as reperfusion injury (3). Although a compendium of therapeutic agents has been proposed to allay the detrimental consequences of reperfusion, they do not yet have desirable efficacies, and the research for discovering novel promising treatments is still ongoing. Preclinical studies are integral to the translation of preliminary research into clinical practice. Conventionally, plausible treatments and innovative drugs are tested in animal experiments to ascertain their effectiveness and safety. Experimentations on cardiac Ischemia/reperfusion injuries comprise a significant body of literature among the preclinical studies, and one can find a myriad of evidence in online databases. Through our systematic reviews, we have encountered various myocardial ischemia/reperfusion (I/R) models, including large vessel ligation, global ischemia by administrating Isoproterenol, and interrupted perfusion of isolated hearts mounted on the Langendorff apparatus. Moreover, the studies were inconsistent regarding the duration of ischemia and, the subsequent reperfusion phase(4, 5). The secondary damages in the course of I/R injury are proportionate to the extent and duration of the ischemia (6). Moreover, Pathways leading to myocardial damage during I/R injury are considered a dynamic and evolving process (7). Therefore, the efficacy of interventions in mitigating I/R injury may be misestimated depending on the duration of the ischemic and reperfusion phases. To surmount these concerns, we suggest an expert panel develop standardized guidelines for myocardial I/R injury induction in experimental studies to consolidate further the reliability and validity of the results obtained from preclinical studies, ultimately contributing to the better appraisal of the studies. In the meantime, tissue markers representative of the degree of infarction or tissue fibrosis can be used to compare the induced ischemia/reperfusion injuries in studies

    Imaging techniques for ocular neoplasia

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    Background: Novel ocular imaging modalities have greatly impacted the diagnosis and management of different types of ocular neoplasia. In this narrative review, we summarize the practical features of popular and novel imaging modalities for ocular tumors. Methods: Four databases, including PubMed/MEDLINE, Web of Science, Scopus, and Google Scholar, were searched from January 1, 2000 to August 31, 2022. Articles reporting different imaging modalities for diagnosing or monitoring treatment responses of ocular tumors were extracted using various combinations of the following keywords: ocular neoplasia, positron emission tomography or PET, single-photon emission computed tomography or SPECT, optical coherence tomography or OCT, OCT angiography or OCTA, computed tomography or CT, ultrasonography or US, ultrasound biomicroscopy or UBM, and magnetic resonance imaging or MRI. Results: Various ocular imaging modalities had different accuracies as adjunctive tools for detecting or managing ocular tumors. Anterior ultra-high-resolution optical coherence tomography (OCT) could be used to evaluate images with < 5-µm resolution. OCT angiography provided deeper insight into retinal vascular changes associated with the malignant transformation of choroidal melanoma. OCT in children altered the diagnosis of suspicious retinoblastoma in 3% of the cases and treatment plan in 11% of the cases. While positron-emission tomography (PET)/computed tomography (CT) allowed the detection of metastatic lesions of choroidal melanoma by full-body scanning, single-photon emission CT was more sensitive compared to PET in detecting choroidal melanoma. Ultrasound biomicroscopy, with an accuracy exceeding 92.5%, could detect retinal calcification in lesions measuring 2–3 mm. Magnetic resonance imaging (MRI) had better contrast compared to ultrasound biomicroscopy and higher sensitivity compared to CT in detecting post-laminar optic nerve invasion. However, MRI had a lower spatial resolution compared to OCT. Further development of imaging modalities and their application in drug development would improve the treatment of ocular tumors. Conclusions: Although diagnosing ocular tumors depend on clinical characteristics, innovations in ocular imaging have enabled early diagnosis and timely, appropriate management of ocular neoplasia, which are conducive to favorable visual outcomes and increased life expectancy. Further systematic reviews and meta-analyses of primary studies focusing on a specific imaging modality in ocular neoplasia could precisely determine the diagnostic accuracy of each imaging modality to better guide eye practitioners with efficient diagnostic or therapeutic approaches for these sight- or life-threatening entities. Imaging modalities may play a major role in drug development in the future

    The knowledge, attitude, and action of Northern Iranian women about cervical cancer and screening

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    Background: Cervical cancer is one of the most prevalent cancers in the world among women which its early diagnosis plays an important role in the prognosis. There are many factors that contribute to the participation in the screening programs, most notably the level of knowledge and attitude of people towards cancer. Understanding the level of these factors in the female population and its association with participation in screening programs is important. Therefore, the aim of this study was to determine the knowledge, attitude and practice of women in the north of Iran to compare these factors between two groups with different baseline knowledge.Methods: This cross-sectional study was carried out among female medical clients and healthcare staff in a healthcare center in the north of Iran. All the eligible patients were interviewed and were asked to fill a questionnaire containing the demographic data, knowledge, attitude, and action about cervical cancer and screening. The data were analyzed by SPSS v24.Results: A total of 283 females entered our study of which 156(55.1%) were clients of the healthcare center and 127(44.9%) were non-physician healthcare staff. Ninety (60.8%) of clients and 39(56.5%) of the staff have performed pap smear at least once (p=0.556). The levels of knowledge and attitude were significantly lower in the clients (p < 0.001 and p=0.003, respectively). There were no significant differences regarding the level of knowledge and attitude between those who performed pap smear and those who did not (0.621 and 0.788, respectively).Conclusions: Increasing awareness, especially improving attitudes in the female population, should be the focus of the health care system to encourage more women to participate in screening programs

    Robot Learning from Demonstration Using Elastic Maps

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    Learning from Demonstration (LfD) is a popular method of reproducing and generalizing robot skills from human-provided demonstrations. In this paper, we propose a novel optimization-based LfD method that encodes demonstrations as elastic maps. An elastic map is a graph of nodes connected through a mesh of springs. We build a skill model by fitting an elastic map to the set of demonstrations. The formulated optimization problem in our approach includes three objectives with natural and physical interpretations. The main term rewards the mean squared error in the Cartesian coordinate. The second term penalizes the non-equidistant distribution of points resulting in the optimum total length of the trajectory. The third term rewards smoothness while penalizing nonlinearity. These quadratic objectives form a convex problem that can be solved efficiently with local optimizers. We examine nine methods for constructing and weighting the elastic maps and study their performance in robotic tasks. We also evaluate the proposed method in several simulated and real-world experiments using a UR5e manipulator arm, and compare it to other LfD approaches to demonstrate its benefits and flexibility across a variety of metrics.Comment: 7 pages, 9 figures, 3 tables. Accepted to IROS 2022. Code available at: https://github.com/brenhertel/ElMapTrajectories Accompanying video at: https://youtu.be/rZgN9Pkw0t
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