University of Louisville

About: University of Louisville is a education organization based out in Louisville, Kentucky, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 24600 authors who have published 49248 publications receiving 1573346 citations. The organization is also known as: UofL.

Does this patient have appendicitis

Abstract: Appendicitis is a common cause of abdominal pain for which prompt diagnosis is rewarded by a marked decrease in morbidity and mortality. The history and physical examination are at least as accurate as any laboratory modality in diagnosing or excluding appendicitis. Those signs and symptoms most helpful in diagnosing or excluding appendicitis are reviewed. The presence of a positive psoas sign, fever, or migratory pain to the right lower quadrant suggests an increased likelihood of appendicitis. Conversely, the presence of vomiting before pain makes appendicitis unlikely. The lack of the classic migration of pain, right lower quadrant pain, guarding, or fever makes appendicitis less likely. This article reviews the literature evaluating the operating characteristics of the most useful elements of the history and physical examination for the diagnosis of appendicitis.

Biocloud: Cloud Computing for Biological, Genomics, and Drug Design

Abstract: Cloud computing has emerged rapidly as an exciting new paradigm that offers a challenging model of computing and services. Leveraging cloud computing technology, bioinformatics tools can be made available as services to anyone, anywhere, and through any device. The use of large biodatasets, its highly demanding algorithms, and the hardware for sudden computational resources makes large-scale biodata analysis an attractive test case for cloud computing. This special issue aims to foster the dissemination of high quality research in any new idea, method, theory, and technique related to cloud computing and bioinformatics and to showcase the most recent developments and research in cloud computing for biological, genomics, and drug design, considering genomics and drug design on the cloud, biological tools on the cloud, biodatabase on the cloud, cloud-based biocomputing, and all kinds of successful applications. The research papers selected for this special issue represent recent progresses in the aspects, including theoretical studies, practical applications, new analysis and modeling technology, programming methodologies, and experimental prototypes. All of these papers not only provide novel ideas and state-of-the-art techniques in the field but also stimulate future research in the biocloud environments.

Tissue-specific muscle, neural and liver stem/progenitor cells reside in the bone marrow, respond to an SDF-1 gradient and are mobilized into peripheral blood during stress and tissue injury

Abstract: Several reports imply that bone marrow hematopoietic stem cells transdifferentiate into tissue-specific stem cells; however, the possibility of committed tissue-specific stem cells pre-existing in the bone marrow has not been dealt with adequately. We present here an alternative explanation of the so-called phenomenon of stem cell transdifferentiation. First, we postulate that tissue-committed stem/progenitor cells circulate in the peripheral blood and compete for tissue-specific niches. The circulation of these cells plays an important physiological role in maintaining a pool of stem cells in distant parts of the body and the number of these cells in peripheral blood can be increased by the administration of agents similar to those used for mobilization of hematopoietic stem cells. Second, we postulate that bone marrow tissue is a source of various stem-cell chemoattractants and survival factors and provides an environment that chemoattracts tissue-specific circulating stem/progenitor cells. In this context, we envision bone marrow as a "home" or "hide-out place" not only of hematopoietic stem cells but also of already differentiated circulating tissue-specific stem/progenitors. In support of this concept, we report here that mRNA of several early markers for muscle (Myf-5, Myo-D), neural (GFAP, nestin) and liver (CK19, fetoprotein) is detectable in circulating (adherent cell-depleted) peripheral blood mononuclear cells. Moreover, using real-time RT-PCR, we found that the level of expression of these markers increases in the peripheral blood of humans and mice after mobilization by G-CSF. Furthermore, using stromal-derived factor-1 (SDF-1) chemotaxis and real-time RT-PCR analysis, we present evidence that early tissue-specific stem cells reside in normal human and murine bone marrow, express the CXCR4 receptor on their surface and can be highly enriched (in humans and mice) after chemotaxis to SDF-1 gradient. All our experiments were performed on freshly isolated cells to exclude the potential contribution of transdifferentiated hematopoietic stem or mesenchymal cells in the culture. We maintain that any transdifferentiation studies employing populations of bone marrow cells should rule out the possibility that the apparently pure hematopoietic stem cell population could in fact contain pre-existing tissue-specific stem/progenitors.

A giant planet undergoing extreme-ultraviolet irradiation by its hot massive-star host

Abstract: The amount of ultraviolet irradiation and ablation experienced by a planet depends strongly on the temperature of its host star. Of the thousands of extrasolar planets now known, only six have been found that transit hot, A-type stars (with temperatures of 7,300–10,000 kelvin), and no planets are known to transit the even hotter B-type stars. For example, WASP-33 is an A-type star with a temperature of about 7,430 kelvin, which hosts the hottest known transiting planet, WASP-33b (ref. 1); the planet is itself as hot as a red dwarf star of type M (ref. 2). WASP-33b displays a large heat differential between its dayside and nightside, and is highly inflated–traits that have been linked to high insolation. However, even at the temperature of its dayside, its atmosphere probably resembles the molecule-dominated atmospheres of other planets and, given the level of ultraviolet irradiation it experiences, its atmosphere is unlikely to be substantially ablated over the lifetime of its star. Here we report observations of the bright star HD 195689 (also known as KELT-9), which reveal a close-in (orbital period of about 1.48 days) transiting giant planet, KELT-9b. At approximately 10,170 kelvin, the host star is at the dividing line between stars of type A and B, and we measure the dayside temperature of KELT-9b to be about 4,600 kelvin. This is as hot as stars of stellar type K4 (ref. 5). The molecules in K stars are entirely dissociated, and so the primary sources of opacity in the dayside atmosphere of KELT-9b are probably atomic metals. Furthermore, KELT-9b receives 700 times more extreme-ultraviolet radiation (that is, with wavelengths shorter than 91.2 nanometres) than WASP-33b, leading to a predicted range of mass-loss rates that could leave the planet largely stripped of its envelope during the main-sequence lifetime of the host star.