Tendencies in medical publications

To describe the trends of research design in publications from high-impact medical journals. Methods: A cross-sectional, descriptive study was conducted by searching the 2011 electronic publications of the journals: New England Journal of Medicine, Journal of the American Medical Association, The Lancet, British Medical Journal, and Annals of Internal Medicine. Studies were classified as primary and secondary. The journal impact factor was taken from the Journal Citation Report website. Descriptive statistics were used to analyze and interpret the data. Results: We analyzed 1130 publications: 804 primary and 326 secondary studies, which represented 71.2% and 28.8% of the total publications, respectively. Among the primary studies, randomized clinical trials (30.4%) were the most prevalent, followed by cohort studies (21.9%) and case reports (9.0%). Conclusions: These findings can have implications in Evidence-Based Medicine programs. Literature review should focus on reviewing secondary articles first, then experimental studies and finally, observational studie

Buněčné mechanismy segregace a konsolidace paměti u potkanního modelu Alzheimerovy choroby

in English Memory is a key component of human cognition that enables individuals to learn and make decisions based on recalling past events. These processes are severely impaired in various neuropathologies, the most socially significant being Alzheimer's disease (AD). Alzheimer's dementia is a progressive neurological disorder that damages memory and also induces pronounced non-cognitive symptoms. Despite extensive research, the cause of AD remains unknown, and its pathophysiology requires intensive study. The transgenic model TgF344-AD mimics the hereditary form of AD, displaying symptoms such as amyloid-beta plaque formation, hyperphosphorylated tau accumulation, and cognitive deficits. In humans, these symptoms often appear earlier than significant amyloid deposition, suggesting that functional impairments precede apparent structural changes. The primary aim of this work is a detailed characterization of the cognitive abilities of spatial navigation and memory in the TgF344-AD model across different age categories-from the period before amyloid plaque formation to their development. Related studies reflect functional cellular and structural changes observed in the same model. This model also serves as a valuable source of information on non-cognitive pathologies associated with AD. Therefore,...in Czech Paměť je klíčovou součástí lidského poznávání, která umožňuje jednotlivcům učit se a rozhodovat na základě vybavování si minulých událostí. Tyto procesy jsou vážně narušeny při rozličných neuropatologiích, z nichž společensky nejzávažnější je Alzheimerova choroba. Alzheimerova demence (AD) je progresivní neurologická porucha, která poškozuje paměť a zároveň vyvolává i výrazné nekognitivní příznaky. Navzdory rozsáhlému výzkumu je příčina AD neznámá, a rovněž její patofyziologie vyžaduje intenzivní studium. Transgenní model TgF344-AD napodobuje dědičnou formu AD projevy, jako je formování amyloid-beta plaků, akumulace hyperfosforylovaného tau a kognitivní deficit. U lidí se yto příznaky často objevují dříve než významné ukládání amyloidu, což naznačuje, že funkční poruchy předcházejí zjevným strukturálním změnám. Hlavním cílem této práce je detailní charakteristika kognitivních schopností prostorové navigace a paměti modelu TgF-344 AD napříč různými věkovými kategoriemi - od období před formováním amyloidových plaků, až po jejich rozvinutí. Další související studie reflektují funkční celulární a strukturální změny, pozorované na stejném modelu. Tento model je též cenným zdrojem informací o nekognitivních patologiích, souvisejících s AD. Proto jsme kvantifikovali úroveň úzkostného chování a...Ústav patologické fyziologieLékařská fakulta v PlzniFaculty of Medicine in Pilse

Estimating Prevalence, Demographics, and Costs of ME/CFS Using Large Scale Medical Claims Data and Machine Learning

Techniques of data mining and machine learning were applied to a large database of medical and facility claims from commercially insured patients to determine the prevalence, gender demographics, and costs for individuals with provider-assigned diagnosis codes for myalgic encephalomyelitis (ME) or chronic fatigue syndrome (CFS). The frequency of diagnosis was 519–1,038/100,000 with the relative risk of females being diagnosed with ME or CFS compared to males 1.238 and 1.178, respectively. While the percentage of women diagnosed with ME/CFS is higher than the percentage of men, ME/CFS is not a “women's disease.” Thirty-five to forty percent of diagnosed patients are men. Extrapolating from this frequency of diagnosis and based on the estimated 2017 population of the United States, a rough estimate for the number of patients who may be diagnosed with ME or CFS in the U.S. is 1.7 million to 3.38 million. Patients diagnosed with CFS appear to represent a more heterogeneous group than those diagnosed with ME. A machine learning model based on characteristics of individuals diagnosed with ME was developed and applied, resulting in a predicted prevalence of 857/100,000 (p > 0.01), or roughly 2.8 million in the U.S. Average annual costs for individuals with a diagnosis of ME or CFS were compared with those for lupus (all categories) and multiple sclerosis (MS), and found to be 50% higher for ME and CFS than for lupus or MS, and three to four times higher than for the general insured population. A separate aspect of the study attempted to determine if a diagnosis of ME or CFS could be predicted based on symptom codes in the insurance claims records. Due to the absence of specific codes for some core symptoms, we were unable to validate that the information in insurance claims records is sufficient to identify diagnosed patients or suggest that a diagnosis of ME or CFS should be considered based solely on looking for presence of those symptoms. These results show that a prevalence rate of 857/100,000 for ME/CFS is not unreasonable; therefore, it is not a rare disease, but in fact a relatively common one

Contrast enhanced X-ray computed tomography imaging of amyloid plaques in Alzheimer disease rat model on lab based micro CT system

Amyloid plaques are small (similar to 50 mu m), highly-dense aggregates of amyloid beta (A beta) protein in brain tissue, supposed to play a key role in pathogenesis of Alzheimer's disease (AD). Plaques' in vivo detection, spatial distribution and quantitative characterization could be an essential marker in diagnostics and evaluation of AD progress. However, current imaging methods in clinics possess substantial limits in sensitivity towards A beta plaques to play a considerable role in AD screening. Contrast enhanced X-ray micro computed tomography (micro CT) is an emerging highly sensitive imaging technique capable of high resolution visualization of rodent brain. In this study we show the absorption based contrast enhanced X-ray micro CT imaging is viable method for detection and 3D analysis of A beta plaques in transgenic rodent models of Alzheimer's disease. Using iodine contrasted brain tissue isolated from the Tg-F344-AD rat model we show the micro CT imaging is capable of precise imaging of A beta plaques, making possible to further analyze various aspects of their 3D spatial distribution and other properties

Evolution of the life cycle in land plants

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92043/1/j.1759-6831.2012.00188.x.pd