Yerevan State Medical University

About: Yerevan State Medical University is a education organization based out in Yerevan, Armenia. It is known for research contribution in the topics: Population & Medicine. The organization has 611 authors who have published 606 publications receiving 5064 citations. The organization is also known as: Yerevan Mkhitar Heratsi State Medical University.

Writing a narrative biomedical review: considerations for authors, peer reviewers, and editors

Abstract: Review articles comprehensively covering a specific topic are crucial for successful research and academic projects. Most editors consider review articles for special and regular issues of journals. Writing a review requires deep knowledge and understanding of a field. The aim of this review is to analyze the main steps in writing a narrative biomedical review and to consider points that may increase the chances of success. We performed a comprehensive search through MEDLINE, EMBASE, Scopus, and Web of Science using the following keywords: review of the literature, narrative review, title, abstract, authorship, ethics, peer review, research methods, medical writing, scientific writing, and writing standards. Opinions expressed in the review are also based on personal experience as authors, peer reviewers, and editors.

Design of biodegradable, implantable devices towards clinical translation

Abstract: Biodegradable materials, including natural and synthetic polymers and hydrolyzable metals, constitute the main components of temporary, implantable medical devices. Besides the intrinsic properties of the materials, the most critical factor determining the successful clinical outcome of implantable and degradable devices is the host response, particularly the immune response, which largely depends on the material features and degradation mechanisms. In this Review, we first survey the state of the art in terms of materials options for use in biodegradable medical devices, focusing on degradation mechanisms and their control. In particular, we highlight silk, which is emerging as an important polymer, owing to its mechanical robustness, bioactive component sequestration, degradability without problematic metabolic products and biocompatibility. We then discuss the host response to these biodegradable materials in terms of dynamic tissue–implant interfaces. Next, we examine the clinical translation of three leading biodegradable material systems — natural and synthetic biodegradable polymers and biodegradable metals — and the related challenges in the context of orthopaedic fixation devices, cardiovascular stents and biodegradable electronic devices. Looking to the future, we propose updated material design strategies to improve the clinical outcomes for these biodegradable medical devices. Clinical outcomes with implantable and degradable devices largely depend on host response. This Review surveys material options and degradation mechanisms relevant to host responses to biodegradable devices, examines clinical translation of leading biodegradable materials and proposes updated material-design strategies to improve device performance.

The Platelet-to-Lymphocyte Ratio as an Inflammatory Marker in Rheumatic Diseases

Abstract: The platelet-to-lymphocyte ratio (PLR) has emerged as an informative marker revealing shifts in platelet and lymphocyte counts due to acute inflammatory and prothrombotic states. PLR has been extensively examined in neoplastic diseases accompanied by immune suppression and thrombosis, which can be predicted by combined blood cell counts and their ratios. Several large observational studies have demonstrated the value of shifts in PLR in evaluating the severity of systemic inflammation and predicting infections and other comorbidities, in inflammatory rheumatic diseases. The value of PLR as an inflammatory marker increases when its fluctuations are interpreted along with other complementary hematologic indices, particularly the neutrophil-to-lymphocyte ratio (NLR), which provides additional information about the disease activity, presence of neutrophilic inflammation, infectious complications, and severe organ damage in systemic lupus erythematosus. PLR and NLR have high predictive value in rheumatic diseases with predominantly neutrophilic inflammation (e.g., Behcet disease and familial Mediterranean fever). High PLR, along with elevated platelet count, is potentially useful in diagnosing some systemic vasculitides, particularly giant-cell arteritis. A few longitudinal studies on rheumatic diseases have demonstrated a decrease in PLR in response to anti-inflammatory therapies. The main limitations of PLR studies are preanalytical faults, inadequate standardization of laboratory measurements, and inappropriate subject selection. Nonetheless, accumulating evidence suggests that PLR can provide valuable information to clinicians who encounter multisystem manifestations of rheumatic diseases, which are reflected in shifts in platelet, lymphocyte, neutrophil, or monocyte counts. Interpretation of PLR combined with complementary hematologic indices is advisable to more accurately diagnose inflammatory rheumatic diseases and predict related comorbidities.

A primate-specific, brain isoform of KCNH2 affects cortical physiology, cognition, neuronal repolarization and risk of schizophrenia

Abstract: Organized neuronal firing is crucial for cortical processing and is disrupted in schizophrenia. Using rapid amplification of 5' complementary DNA ends in human brain, we identified a primate-specific isoform (3.1) of the ether-a-go-go-related K(+) channel KCNH2 that modulates neuronal firing. KCNH2-3.1 messenger RNA levels are comparable to full-length KCNH2 (1A) levels in brain but three orders of magnitude lower in heart. In hippocampus from individuals with schizophrenia, KCNH2-3.1 expression is 2.5-fold greater than KCNH2-1A expression. A meta-analysis of five clinical data sets (367 families, 1,158 unrelated cases and 1,704 controls) shows association of single nucleotide polymorphisms in KCNH2 with schizophrenia. Risk-associated alleles predict lower intelligence quotient scores and speed of cognitive processing, altered memory-linked functional magnetic resonance imaging signals and increased KCNH2-3.1 mRNA levels in postmortem hippocampus. KCNH2-3.1 lacks a domain that is crucial for slow channel deactivation. Overexpression of KCNH2-3.1 in primary cortical neurons induces a rapidly deactivating K(+) current and a high-frequency, nonadapting firing pattern. These results identify a previously undescribed KCNH2 channel isoform involved in cortical physiology, cognition and psychosis, providing a potential new therapeutic drug target.

Novel insights and therapeutic interventions for pediatric osteosarcoma

Abstract: High-grade osteosarcomas are the most common primary malignant tumors of bone. With complete surgical resection and multi-agent chemotherapy up to 70% of patients with high-grade osteosarcomas and localized extremity tumors can become long-term survivors. The prognosis, however, is poor for patients with nonresectable, primary metastatic or relapsed disease. Outcome is essentially unchanged for three decades. Herein, we describe selected novel insights into the genomics, biology and immunology of the disease and discuss selected strategies, which hold promise to overcome the current stagnation in the therapeutic success in childhood osteosarcoma.