SLSC Otterbein College Foreign Study Programs

Descriptions of Otterbein College\u27s different foreign study programs as of the 1969-1970 academic year

SLSC Seminar Planning Fall Semester 1970-1971

Dr. Addington\u27s handwritten outline for the Sierra Leone Program Fall seminar course, 1970-1971, on the back of copies of the September 23 and September 24 editions of the Daily Data at Otterbein. A transcript of the handwritten schedule is available as a separate file below

Inhaled Carbon Monoxide Provides Cerebral Cytoprotection in Pigs

Carbon monoxide (CO) at low concentrations imparts protective effects in numerous preclinical small animal models of brain injury. Evidence of protection in large animal models of cerebral injury, however, has not been tested. Neurologic deficits following open heart surgery are likely related in part to ischemia reperfusion injury that occurs during cardiopulmonary bypass surgery. Using a model of deep hypothermic circulatory arrest (DHCA) in piglets, we evaluated the effects of CO to reduce cerebral injury. DHCA and cardiopulmonary bypass (CPB) induced significant alterations in metabolic demands, including a decrease in the oxygen/glucose index (OGI), an increase in lactate/glucose index (LGI) and a rise in cerebral blood pressure that ultimately resulted in increased cell death in the neocortex and hippocampus that was completely abrogated in piglets preconditioned with a low, safe dose of CO. Moreover CO-treated animals maintained normal, pre-CPB OGI and LGI and corresponding cerebral sinus pressures with no change in systemic hemodynamics or metabolic intermediates. Collectively, our data demonstrate that inhaled CO may be beneficial in preventing cerebral injury resulting from DHCA and offer important therapeutic options in newborns undergoing DHCA for open heart surgery

Carbon Monoxide Protects against Liver Failure through Nitric Oxide–induced Heme Oxygenase 1

Carbon monoxide (CO) and nitric oxide (NO) each have mechanistically unique roles in various inflammatory disorders. Although it is known that CO can induce production of NO and that NO can induce expression of the cytoprotective enzyme heme oxygenase 1 (HO-1), there is no information whether the protective effect of CO ever requires NO production or whether either gas must induce expression of HO-1 to exert its functional effects. Using in vitro and in vivo models of tumor necrosis factor α–induced hepatocyte cell death in mice, we find that activation of nuclear factor κB and increased expression of inducible NO are required for the protective effects of CO, whereas the protective effects of NO require up-regulation of HO-1 expression. When protection from cell death is initiated by CO, NO production and HO-1 activity are each required for the protective effect showing for the first time an essential synergy between these two molecules in tandem providing potent cytoprotection

Hard X-ray detection of the high redshift quasar 4C 71.07

BATSE/OSSE observations of the high redshift quasar 4C 71.07 indicate that this is the brightest and furthest AGN so far detected above 20 keV. BATSE Earth occultation data have been used to search for emission from 4C 71.07 from nearly 3 years of observation. The mean source flux over the whole period in the BATSE energy range 20-100 keV is (13.2 +/- 1.06) x 10^(-11) erg cm^(-2) s^(-1) corresponding to a luminosity of 2 x 10^(48) erg s^(-1). The BATSE light curve over the 3 years of observations shows several flare-like events, one of which (in January 1996) is associated with an optical flare (R=16.1) but with a delay of 55 days. The OSSE/BATSE spectral analysis indicates that the source is characterized by a flat power spectrum (Gamma about 1.1 - 1.3) when in a low state; this spectral form is consistent within errors with the ASCA and ROSAT spectra. This means that the power law observed from 0.1 to 10 keV extends up to at least 1 MeV but steepens soon after to meet EGRET high energy data. BATSE data taken around the January 1996 flare suggests that the spectrum could be steeper when the source is in a bright state. The nuF-nu representation of the source is typical of a low frequency peaked/gamma-ray dominated blazar, with the synchrotron peak in the mm-FIR band and the Compton peak in the MeV band. The BATSE and OSSE spectral data seem to favour a model in which the high energy flux is due to the sum of the synchrotron self-Compton and the external Compton contributions; this is also supported by the variability behaviour of the source.Comment: 19 pages, LaTeX, plus 4 .ps figures. accepted by Astrophysical Journa

Heme oxygenase-1 derived carbon monoxide permits maturation of myeloid cells

Critical functions of the immune system are maintained by the ability of myeloid progenitors to differentiate and mature into macrophages. We hypothesized that the cytoprotective gas molecule carbon monoxide (CO), generated endogenously by heme oxygenases (HO), promotes differentiation of progenitors into functional macrophages. Deletion of HO-1, specifically in the myeloid lineage (Lyz-Cre:Hmox1flfl), attenuated the ability of myeloid progenitors to differentiate toward macrophages and decreased the expression of macrophage markers, CD14 and macrophage colony-stimulating factor receptor (MCSFR). We showed that HO-1 and CO induced CD14 expression and efficiently increased expansion and differentiation of myeloid cells into macrophages. Further, CO sensitized myeloid cells to treatment with MCSF at low doses by increasing MCSFR expression, mediated partially through a PI3K-Akt-dependent mechanism. Exposure of mice to CO in a model of marginal bone marrow transplantation significantly improved donor myeloid cell engraftment efficiency, expansion and differentiation, which corresponded to increased serum levels of GM-CSF, IL-1α and MCP-1. Collectively, we conclude that HO-1 and CO in part are critical for myeloid cell differentiation. CO may prove to be a novel therapeutic agent to improve functional recovery of bone marrow cells in patients undergoing irradiation, chemotherapy and/or bone marrow transplantation

Gamma-loud quasars: a view with BeppoSAX

We present $Beppo$SAX observations of the $\gamma$-ray emitting quasars 0836+710, 1510-089 and 2230+114. All the objects have been detected in the PDS up to 100 keV and have extremely flat power-law spectra above 2 keV ($\alpha _x$=0.3--0.5). 0836+710 shows absorption higher than the galactic value and marginal evidence for the presence of the redshifted 6.4 keV Iron line. 1510-089 shows a spectral break around 1 keV, with the low energy spectrum steeper ($\alpha_l$=1.6) than the high energy power-law ($\alpha_h$=0.3). The data are discussed in the light of current Inverse Compton models for the high energy emission.Comment: 4 pages, 2 figures, to appear in the proceedings of the conference "X-Ray Astronomy '99", Bologna, Italy, September 199

Rms-flux relation in the optical fast variability data of BL Lacertae object S5 0716+714

The possibility that BL Lac S5 0716+714 exhibits a linear root mean square (rms)-flux relation in its IntraDay Variability (IDV) is analysed. The results may be used as an argument in the existing debate regarding the source of optical IDV in Active Galactic Nuclei. 63 time series in different optical bands were used. A linear rms-flux relation at a confidence level higher than 65% was recovered for less than 8% of the cases. We were able to check if the magnitude is log-normally distributed for eight timeseries and found, with a confidence > 95%, that this is not the case.Comment: Accepted by Astrophysics and Space Scienc

Escherichia coli heme oxygenase modulates host innate immune responses: Bacteria modulate the immune response

Induction of mammalian heme oxygenase-1 and exposure of animals to carbon monoxide ameliorates experimental colitis. When enteric bacteria, including Escherichia coli, are exposed to low iron conditions, they express an heme oxygenase-like enzyme, chuS, and metabolize heme into iron, biliverdin and carbon monoxide. Given the abundance of enteric bacteria residing in the intestinal lumen, we hypothesized that commensal intestinal bacteria may be a significant source of carbon monoxide, with the consequence that enteric bacteria expressing chuS and other heme oxygenase -like molecules suppress inflammatory immune responses through release of carbon monoxide. Carbon monoxide exposed mice have altered enteric bacterial composition and increased E. coli 16S and chuS DNA by real-time PCR. Moreover, severity of experimental colitis correlates with increased E. coli chuS expression in IL-10 deficient mice. To explore functional roles, E. coli were genetically modified to overexpress chuS or the chuS gene was deleted. Co-culture of chuS-overexpressing E. coli with bone marrow derived macrophages results in decreased IL-12 p40 and increased IL-10 secretion compared to wild-type or chuS-deficient E. coli. Mice infected with chuS-overexpressing E. coli have increased levels of hepatic carbon monoxide and decreased serum IL-12 p40 compared to mice infected with chuS-deficient E. coli. Thus, carbon monoxide alters the composition of the commensal intestinal microbiota and expands E. coli populations harboring the chuS gene. These bacteria are capable of attenuating innate immune responses through expression of chuS. Bacterial heme oxygenase -like molecules and bacterial-derived carbon monoxide may represent novel targets for therapeutic intervention in inflammatory conditions