African American Adults’ Experiences with the Health Care System: In Their Own Words

African Americans suffer a disproportionate burden of death and illness from a number of different chronic diseases. Inequalities in health care practices and poor patient and provider communication between African American patients and health care professionals contribute to these disparities. We describe findings from focus groups with 79 urban African Americans in which the participants discussed their interactions with the healthcare system as well as beliefs and opinions of the healthcare system and professionals. Analysis revealed five major themes: (1) historical and contextual foundations; (2) interpersonal experiences with physicians and other health care workers; (3) discrimination; (4) trust, opinions and attitudes, and (5) improving health care experiences. These findings indicate that perceptions of discrimination and racism were prevalent among African Americans in this study, and that the expectation of a negative interaction is a barrier to seeking care. Authors discuss prevention and public health implications of these findings and make recommendations for health care practitioners

Preliminary Investigation of Rural-Use Aquifers of Boone, Carroll, and Madison Counties, Arkansas

Approximately 500 water wells having driller\u27s lithologic logs were plottedin Boone, Carroll, and Madison Counties, Arkansas. Three aquifers were found to be used by the rural residents and smaller communities. The most shallow of these is the Mississippian Boone-St. Joe aquifer. This aquifer is generally the least productive having a range of .25 to 60 gpm but a median productivity of only 5 gpm. Well depths for the Boone-St. Joe range from 46 to 464 ft. and have a median depth of 225 ft. The Boone-St. Joe aquifer is unconfined to semi-confined and yields sufficient quantities of water only when there is an adequate saturated thickness (generally\u3e100 ft.) and/or a fracture or water-filled cave is intersected. The next aquifer is the first sand below the Chattanooga Shale which can be composed on one to three of the following sandstones: upper Everton, Clifty, and/or Sylamore. The range in yield for this newly designated aquifer is 1 to 70 gpm with a median productivity of 10 gpm. Well depths for the aquifer range from 150 to 824 ft. with a median depth of 460 feet. An isopach map was prepared for this sandstone aquifer zone. There is a rapid thinning trend to the north from 250 ft in central Madison County to 0 ft near the Missouri border. If there is insufficiency or permeability of this aquifer, residents must drill deeper to the Cotter Dolomite. The Cotter-Jefferson City Dolomite is the next aquifer below the Sylamore-Clifty-Everton aquifer. This aquifer zone has a range in yield of 1.5 to 200 gpm and a median yield of 15 gpm. Well depths range from 130 to 1010 ft. with a median depth of 475 feet. A statistical correlation procedure was made among well yield (gpm), photo-lineament proximity, and regolith thickness for all these aquifers in Boone County. The results indicate that more water can be obtained in areas of deep weathering and that deeper weathering is found closer to photo-lineaments. A strong relationship between lineament proximity and yield exists when the aquifers are combined but not for each of the individual aquifers

Libraries in Medical Education (LIME): A Special Interest Group of NEGEA

Purpose: Health science librarians play key roles in medical education by providing curriculum-integrated information skills instruction; by assisting faculty with research; by purchasing and maintaining collections of information resources; by participating in the development of standards and guidelines for educational outcomes; and by creating and managing libraries conducive to education. A group of medical librarians from northeastern medical schools proposed Libraries in Medical Education (LIME) Special Interest Group (SIG) to benefit all NEGEA (Northeast Group on Educational Affairs) members. The SIG will promote communication and collaboration between librarians and NEGEA members on research and curricular initiatives; enhance librarians knowledge and skills of current trends and issues of interest to the medical education community; recognize librarians as valued components of the medical education team; and increase the professional knowledge and skills of NEGEA members through programming delivered at annual meetings by librarians. Methods: In 2006, medical librarians drafted and submitted a proposal to become an official LIME SIG. Librarians have successfully implemented special interest groups within professional organizations. The Libraries in Medical Education SIG instituted within the Central Group on Education Affairs and the active Libraries/Educational Resources Section of American Association of Colleges of Pharmacy (AACP) served as models. Results: In 2007, the LIME was officially accepted by NEGEA as a special interest group. Conclusion: An enthusiastic LIME-SIG group looks forward to an exciting future of collaboration. Presented at the Northeast Group for Educational Affairs Annual Educational Retreat held in Stony Brook, NY, on June 8, 2007

Interaction of Mitochondrial Elongation Factor Tu With Aminoacyl-tRNA and Elongation Factor Ts

Elongation factor (EF) Tu promotes the binding of aminoacyl-tRNA (aa-tRNA) to the acceptor site of the ribosome. This process requires the formation of a ternary complex (EF-Tu·GTP·aa-tRNA). EF-Tu is released from the ribosome as an EF-Tu·GDP complex. Exchange of GDP for GTP is carried out through the formation of a complex with EF-Ts (EF-Tu·Ts). Mammalian mitochondrial EF-Tu (EF-Tumt) differs from the corresponding prokaryotic factors in having a much lower affinity for guanine nucleotides. To further understand the EF-Tumt subcycle, the dissociation constants for the release of aa-tRNA from the ternary complex (K tRNA) and for the dissociation of the EF-Tu·Tsmt complex (K Ts) were investigated. The equilibrium dissociation constant for the ternary complex was 18 ± 4 nM, which is close to that observed in the prokaryotic system. The kinetic dissociation rate constant for the ternary complex was 7.3 × 10− 4 s− 1, which is essentially equivalent to that observed for the ternary complex inEscherichia coli. The binding of EF-Tumt to EF-Tsmt is mutually exclusive with the formation of the ternary complex. K Ts was determined by quantifying the effects of increasing concentrations of EF-Tsmt on the amount of ternary complex formed with EF-Tumt. The value obtained for K Ts(5.5 ± 1.3 nM) is comparable to the value ofK tRNA

Reduced lateral mobility of a fluorescent lipid probe in cholesterol-depleted erythrocyte membrane

The effect of cholesterol depletion of the human erythrocyte membrane on the lateral diffusion rate of a fluorescent lipid probe is reported. At low temperatures (-5 to 5[deg]C), the diffusion of the probe is 50% slower in the cholesterol-depleted membrane than in non-depleted membrane. At high temperatures (30 to 40[deg] C), probe mobility is not affected by cholesterol depletion. These results suggest that cholesterol suppresses aspects of phospholipid phase changes in animal cells in a manner consistent with its behavior in artificial bilayers and multilayers.Whole erythrocytes were depleted of 30-50% of their cholesterol by incubation with a sonicated dispersion of dipalmitoyl phosphatidylcholine. Cells were then labeled with 3,3'-dioctadecylindocarbocyanine (diI), a phospholipid-like fluorescent dye, and hemolyzed into spherical ghosts. The rate of lateral motion of diI was measured by observing the fluorescence recovery after local photobleaching with a focused laser spot.The diffusion rate of the lipid probe in both control and cholesterol-depleted erythrocyte membrane is substantially smaller than in any cell or model membrane previously measured.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23287/1/0000224.pd

Total internal reflection with fluorescence correlation spectroscopy: Applications to substrate-supported planar membranes

In this review paper, the conceptual basis and experimental design of total internal reflection with fluorescence correlation spectroscopy (TIR-FCS) is described. The few applications to date of TIR-FCS to supported membranes are discussed, in addition to a variety of applications not directly involving supported membranes. Methods related, but not technically equivalent, to TIR-FCS are also summarized. Future directions for TIR-FCS are outlined

Distribution and lateral mobility of DC-SIGN on immature dendritic cells-implications for pathogen uptake

The receptor C-type lectin DC-SIGN (CD209) is expressed by immature dendritic cells, functioning as an antigen capture receptor and cell adhesion molecule. Various microbes, including HIV-1, can exploit binding to DC-SIGN to gain entry to dendritic cells. DC-SIGN forms discrete nanoscale clusters on immature dendritic cells that are thought to be important for viral binding. We confirmed that these DC-SIGN clusters also exist both in live dendritic cells and in cell lines that ectopically express DC-SIGN. Moreover, DC-SIGN has an unusual polarized lateral distribution in the plasma membrane of dendritic cells and other cells: the receptor is preferentially localized to the leading edge of the dendritic cell lamellipod and largely excluded from the ventral plasma membrane. Colocalization of DC-SIGN clusters with endocytic activity demonstrated that surface DC-SIGN clusters are enriched near the leading edge, whereas endocytosis of these clusters occurred preferentially at lamellar sites posterior to the leading edge. Therefore, we predicted that DC-SIGN clusters move from the leading edge to zones of internalization. Two modes of lateral mobility were evident from the trajectories of DC-SIGN clusters at the leading edge, directed and non-directed mobility. Clusters with directed mobility moved in a highly linear fashion from the leading edge to rearward locations in the lamella at remarkably high velocity (1420+/-260 nm/second). Based on these data, we propose that DC-SIGN clusters move from the leading edge--where the dendritic cell is likely to encounter pathogens in tissue--to a medial lamellar site where clusters enter the cell via endocytosis. Immature dendritic cells may acquire and internalize HIV and other pathogens by this process

Rifampicin-Independent Interactions between the Pregnane X Receptor Ligand Binding Domain and Peptide Fragments of Coactivator and Corepressor Proteins

The pregnane X receptor (PXR), a member of the nuclear receptor superfamily, regulates the expression of drug-metabolizing enzymes in a ligand-dependent manner. The conventional view of nuclear receptor action is that ligand binding enhances the receptor's affinity for coactivator proteins, while decreasing its affinity for corepressors. To date, however, no known rigorous biophysical studies have been conducted to investigate the interaction among PXR, its coregulators, and ligands. In this work, steady-state total internal reflection fluorescence microscopy (TIRFM) and total internal reflection with fluorescence recovery after photobleaching were used to measure the thermodynamics and kinetics of the interaction between the PXR ligand binding domain and a peptide fragment of the steroid receptor coactivator-1 (SRC-1) in the presence and absence of the established PXR agonist, rifampicin. Equilibrium dissociation and dissociation rate constants of ~5 μM and ~2 s(-1), respectively, were obtained in the presence and absence of rifampicin, indicating that the ligand does not enhance the affinity of the PXR and SRC-1 fragments. Additionally, TIRFM was used to examine the interaction between PXR and a peptide fragment of the corepressor protein, the silencing mediator for retinoid and thyroid receptors (SMRT). An equilibrium dissociation constant of ~70 μM was obtained for SMRT in the presence and absence of rifampicin. These results strongly suggest that the mechanism of ligand-dependent activation in PXR differs significantly from that seen in many other nuclear receptors