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.

A Randomized, Controlled Trial of Interferon Alfa-2b Alone and after Prednisone Withdrawal for the Treatment of Chronic Hepatitis B

Abstract: Background and Methods. Chronic hepatitis B is a common and often progressive liver disorder for which there is no accepted therapy. To assess the efficacy of treatment with interferon, we randomly assigned patients with chronic hepatitis B to one of the following regimens: prednisone for 6 weeks followed by 5 million units of recombinant interferon alfa-2b daily for 16 weeks; placebo followed by 5 million units of interferon daily for 16 weeks; placebo followed by 1 million units of interferon daily for 16 weeks; or observation with no treatment. Results. Hepatitis B e antigen and hepatitis B viral DNA disappeared from serum significantly more often in the patients given prednisone plus interferon (16 of 44 patients, or 36 percent) or 5 million units of interferon alone (15 of 41; 37 percent) than in the untreated controls (3 of 43; 7 percent; P<0.001); the difference between those given 1 million units of interferon (7 of 41; 17 percent) and the controls was not significant. The strongest indep...

Trafficking of Normal Stem Cells and Metastasis of Cancer Stem Cells Involve Similar Mechanisms: Pivotal Role of the SDF-1–CXCR4 Axis

Abstract: The alpha-chemokine stromal-derived factor (SDF)-1 and the G-protein-coupled seven-span transmembrane receptor CXCR4 axis regulates the trafficking of various cell types. In this review, we present the concept that the SDF-1-CXCR4 axis is a master regulator of trafficking of both normal and cancer stem cells. Supporting this is growing evidence that SDF-1 plays a pivotal role in the regulation of trafficking of normal hematopoietic stem cells (HSCs) and their homing/retention in bone marrow. Moreover, functional CXCR4 is also expressed on nonhematopoietic tissue-committed stem/progenitor cells (TCSCs); hence, the SDF-1-CXCR4 axis emerges as a pivotal regulator of trafficking of various types of stem cells in the body. Furthermore, because most if not all malignancies originate in the stem/progenitor cell compartment, cancer stem cells also express CXCR4 on their surface and, as a result, the SDF-1-CXCR4 axis is also involved in directing their trafficking/metastasis to organs that highly express SDF-1 (e.g., lymph nodes, lungs, liver, and bones). Hence, we postulate that the metastasis of cancer stem cells and trafficking of normal stem cells involve similar mechanisms, and we discuss here the common molecular mechanisms involved in these processes. Finally, the responsiveness of CXCR4+ normal and malignant stem cells to an SDF-1 gradient may be regulated positively/primed by several small molecules related to inflammation which enhance incorporation of CXCR4 into membrane lipid rafts, or may be inhibited/blocked by small CXCR4 antagonist peptides. Consequently, strategies aimed at modulating the SDF-1-CXCR4 axis could have important clinical applications both in regenerative medicine to deliver normal stem cells to the tissues/organs and in clinical hematology/oncology to inhibit metastasis of cancer stem cells.

Analysis of defect generation in Ti–6Al–4V parts made using powder bed fusion additive manufacturing processes

Abstract: Ti–6Al–4V parts made using additive manufacturing processes such as selective laser melting (SLM) and electron beam melting (EBM) are subject to the inclusion of defects. This study purposely fabricated Ti–6Al–4V samples with defects by varying process parameters from the factory default settings in both SLM and EBM systems. Process parameters are classified according to their tendency to create certain types of porosity. Finally, defect characteristics are discussed with respect to defect generation mechanisms; and effective process windows for SLM and EBM system are discussed.

Initial clinical manifestations of Parkinson's disease: features and pathophysiological mechanisms

Abstract: A dopaminergic deficiency in patients with Parkinson's disease (PD) causes abnormalities of movement, behaviour, learning, and emotions. The main motor features (ie, tremor, rigidity, and akinesia) are associated with a deficiency of dopamine in the posterior putamen and the motor circuit. Hypokinesia and bradykinesia might have a dual anatomo-functional basis: hypokinesia mediated by brainstem mechanisms and bradykinesia by cortical mechanisms. The classic pathophysiological model for PD (ie, hyperactivity in the globus pallidus pars interna and substantia nigra pars reticulata) does not explain rigidity and tremor, which might be caused by changes in primary motor cortex activity. Executive functions (ie, planning and problem solving) are also impaired in early PD, but are usually not clinically noticed. These impairments are associated with dopamine deficiency in the caudate nucleus and with dysfunction of the associative and other non-motor circuits. Apathy, anxiety, and depression are the main psychiatric manifestations in untreated PD, which might be caused by ventral striatum dopaminergic deficit and depletion of serotonin and norepinephrine. In this Review we discuss the motor, cognitive, and psychiatric manifestations associated with the dopaminergic deficiency in the early phase of the parkinsonian state and the different circuits implicated, and we propose distinct mechanisms to explain the wide clinical range of PD symptoms at the time of diagnosis.