A rationally designed small molecule for identifying an <i>in vivo</i> link between metal–amyloid-β complexes and the pathogenesis of Alzheimer's disease

Beck, Michael W.,Oh, Shin Bi,Kerr, Richard A.,Lee, Hyuck Jin,Kim, So Hee,Kim, Sujeong,Jang, Milim,Ruotolo, Brandon T.,Lee, Joo-Yong,Lim, Mi Hee Royal Society of Chemistry 2015 Chemical Science Vol.6 No.3

<▼1><P>An <I>in vivo</I> chemical tool designed to target metal–Aβ complexes and modulate their activity was applied to the 5XFAD mouse model of Alzheimer’s disease (AD) demonstrating the involvement of metal–Aβ in AD pathology.</P></▼1><▼2><P>Multiple factors, including amyloid-β (Aβ), metals, and reactive oxygen species (ROS), are involved in the development of Alzheimer's disease (AD). Metal ions can interact with Aβ species generating toxic oligomers and ROS <I>in vitro</I>; however, the involvement of metal–Aβ complexes in AD pathology <I>in vivo</I> remains unclear. To solve this uncertainty, we have developed a chemical tool (<B>L2-b</B>) that specifically targets metal–Aβ complexes and modulates their reactivity (<I>i.e.</I>, metal–Aβ aggregation, toxic oligomer formation, and ROS production). Through the studies presented herein, we demonstrate that <B>L2-b</B> is able to specifically interact with metal–Aβ complexes over metal-free Aβ analogues, redirect metal–Aβ aggregation into off-pathway, nontoxic less structured Aβ aggregates, and diminish metal–Aβ-induced ROS production, overall mitigating metal–Aβ-triggered toxicity, confirmed by multidisciplinary approaches. <B>L2-b</B> is also verified to enter the brain <I>in vivo</I> with relative metabolic stability. Most importantly, upon treatment of 5XFAD AD mice with <B>L2-b</B>, (i) metal–Aβ complexes are targeted and modulated in the brain; (ii) amyloid pathology is reduced; and (iii) cognition deficits are significantly improved. To the best of our knowledge, by employing an <I>in vivo</I> chemical tool specifically prepared for investigating metal–Aβ complexes, we report for the first time experimental evidence that metal–Aβ complexes are related directly to AD pathogenesis.</P></▼2>

Sputum Inflammatory Mediators Are Increased in Aspergillus fumigatus Culture-Positive Asthmatics

Michael A Ghebre,Dhananjay Desai,Amisha Singapuri,Joanne Woods,Laura Rapley,Suzanne Cohen,Athula Herath,Andrew J Wardlaw,Catherine H Pashley,Richard May,Chris E Brightling 대한천식알레르기학회 2017 Allergy, Asthma & Immunology Research Vol.9 No.2

Aspergillus fumigatus sensitization and culture in asthma are associated with disease severity and lung function impairment, but their relationship with airway inflammation is poorly understood. We investigated the profile of 24 sputum inflammatory mediators in A. fumigatus culture-positive or-negative moderate-to-severe asthmatics. Fifty-two subjects were recruited from a single center. A. fumigatus was cultured from 19 asthmatics. Asthma control, symptom score, lung function, and sputum cell count were not significantly different between the asthmatics with and without a positive A. fumigatus culture. All of the sputum mediators were numerically increased in subjects with a positive versus negative sputum A. fumigatus culture. Sputum TNF-R2 was significantly elevated (P=0.03) and the mediator that best distinguished A. fumigatus culture-positive from culturenegative subjects (receiver-operator characteristic area under the curve 0.66 [95% CI: 0.51 to 0.82, P=0.045]). A. fumigates-positive culture in moderate- to-severe asthma is associated with increased inflammatory sputum mediators.

Mass Production of Pullulan with Optimized Concentrations of Carbon and Nitrogen Sources by Aureobasidium pullulans HP-2001 in a 100-L Bioreactor with the Inner Pressure

( Seo Hyung Pil ),( Chung Han Chung ),( Sung Koo Kim ),( Richard A Gross ),( David L. Kaplan ),( Jin Woo Lee ) 한국미생물생명공학회 2004 Journal of microbiology and biotechnology Vol.14 No.2

The Hexameric Helicase DnaB Adopts a Nonplanar Conformation during Translocation

Itsathitphaisarn, O.,Wing, Richard A.,Eliason, William K.,Wang, J.,Steitz, Thomas A. Cell Press ; MIT Press 2012 Cell Vol.151 No.2

DNA polymerases can only synthesize nascent DNA from single-stranded DNA (ssDNA) templates. In bacteria, the unwinding of parental duplex DNA is carried out by the replicative DNA helicase (DnaB) that couples NTP hydrolysis to 5' to 3' translocation. The crystal structure of the DnaB hexamer in complex with GDP-AlF<SUB>4</SUB> and ssDNA reported here reveals that DnaB adopts a closed spiral staircase quaternary structure around an A-form ssDNA with each C-terminal domain coordinating two nucleotides of ssDNA. The structure not only provides structural insights into the translocation mechanism of superfamily IV helicases but also suggests that members of this superfamily employ a translocation mechanism that is distinct from other helicase superfamilies. We propose a hand-over-hand mechanism in which sequential hydrolysis of NTP causes a sequential 5' to 3' movement of the subunits along the helical axis of the staircase, resulting in the unwinding of two nucleotides per subunit.

Cytokines Stimulate Lung Epithelial Cells to Release Nitric Oxide

Robbins, Richard A.,Kwon, O-Jung The Korean Academy of Tuberculosis and Respiratory 1995 Tuberculosis and Respiratory Diseases Vol.42 No.4

Cytokine release from alveolar macrophages and subsequent interaction of these cytokines with the bronchial epithelium can induce epithelial cells to release inflammatory mediators. Nitric oxide(NO), a highly reactive gas formed from arginine by nitric oxide synthase(NOS), is known to be involved in inflammation and edema formation, and the inducible form of NOS(iNOS) can be increased by cytokines. In this context, we hypothesized that lung epithelial cells could be stimulated by cytokines released by alveolar macrophages to express iNOS. To test this hypothesis, the murine lung epithelial cell line, LA-4, or the human lung epithelial cell line, A549, were stimulated with culture supernatant fluids from alveolar macrophages. NO production was assessed by evaluating the culture supernatant fluids for nitrite and nitrate, the stable end products of NO. Both murine and human cell culture supernatant fluids demonstrated an increase in nitrite and nitrate which were time- and dose-dependent and attenuated by $TNF{\alpha}$ and IL-$1{\beta}$ antibodies(p<0.05, all comparisons). Consistent with these observations, cytomix a combination of $TNF{\alpha}$, IL-$1{\beta}$, and $\gamma$-interferon, stimulated the lung epithelial cell lines as well as primary cultures of human bronchial epithelial cells to increase their NO production as evidenced by an increase in nitrite and nitrate in their culture supernatant fluids, an increase in the iNOS staining by immunocytochemistry, and an increase in iNOS mRNA by Northern blottin(p<0.05, all comparisons). The cytokine effects on iNOS were all attenuated by dexamethasone. To determine if these in vitro observations are reflected in vivo, exhaled NO was measured and found to be increased in asthmatics not receiving corticosteroids. These data demonstrate that alveolar macrophage derived cytokines increase iNOS expression in lung epithelial cells and that these in vitro observations are mirrored by increased exhaled NO levels in asthmatics. Increased NO in the lung may contribute to edema formation and airway narrowing.

Night shift preparation, performance, and perception: are there differences between emergency medicine nurses, residents, and faculty?

John R. Richards,Taylor L. Stayton,Jason A. Wells,Aman K. Parikh,Erik G. Laurin 대한응급의학회 2018 Clinical and Experimental Emergency Medicine Vol.5 No.4

Objective Determine differences between faculty, residents, and nurses regarding night shift preparation, performance, recovery, and perception of emotional and physical health effects. Methods Survey study performed at an urban university medical center emergency department with an accredited residency program in emergency medicine. Results Forty-seven faculty, 37 residents, and 90 nurses completed the survey. There was no difference in use of physical sleep aids between groups, except nurses utilized blackout curtains more (69%) than residents (60%) and faculty (45%). Bedroom temperature preference was similar. The routine use of pharmacologic sleep aids differed: nurses and residents (both 38%) compared to faculty (13%). Residents routinely used melatonin more (79%) than did faculty (33%) and nurses (38%). Faculty preferred not to eat (45%), whereas residents (24%) preferred a full meal. The majority (>72%) in all groups drank coffee before their night shift and reported feeling tired despite their routine, with 4:00 a.m. as median nadir. Faculty reported a higher rate (41%) of falling asleep while driving compared to residents (14%) and nurses (32%), but the accident rate (3% to 6%) did not differ significantly. All had similar opinions regarding night shift-associated health effects. However, faculty reported lower level of satisfaction working night shifts, whereas nurses agreed less than the other groups regarding increased risk of drug and alcohol dependence. Conclusion Faculty, residents, and nurses shared many characteristics. Faculty tended to not use pharmacologic sleep aids, not eat before their shift, fall asleep at a higher rate while driving home, and enjoy night shift work less.

Nonlinear characteristics in the magnetoconductance of electron billiards

Matthew S. Fairbanks,Colleen A. Marlow,Richard P. Taylor,Heiner Linke 한국물리학회 2008 Current Applied Physics Vol.8 No.3,4

The effect of an applied bias on transport through an electron billiard is studied by analysis of magnetoconductance uctuations. It isshown that at low bias, nonlinear eects are well-described by electron heating alone, while at higher bias (V > 2 mV, or approximately 5% of the electron Fermi energy) non-equilibrium eects become signicant. We chart this behavior by examining the eective electrontemperature plotted against the empirical parameter Q (average energy level spacing over energy level broadening) and the spectral scal-ing exponent a. The high bias data shows a departure from a curve composed of lattice temperature data for the same device, which indicates a change in electron dynamics within the billiard.

Biosynthesis of Novel Exopolymers by Aureobasidium pullulans

Lee,Jin W.,Deng,Fang,Yeomans,Walter G.,Allen,Alfred L.,Gross,Richard A.,Kaplan,David L. 한국생명과학회 1998 한국생명과학회 학술발표회 Vol.20 No.-

Exopolymers produced by A. pullulans ATCC 42023 under aerobic conditions with glucose, mannose, and glucose analogs including 3-O- methyl-D-glucose, glucosamine, N-acetylglucosamine, and 2-deoxy-D- glucose as carbon sources contained glucose and mannose. The molar ratio of glucose to mannose in exopolymers and the molecular weight of exopolymers varied with the carbon source and culture time. Exopolymers synthesized with glucose and mannose as carbon sources showed glucose contents of 87±3 and 89±2%, respectively, with a decreased molecular weight from 3.50 - 2.12 x 10^6 to 0.85 - 0.77 x 10^6 with culture time. The molar ratio of glucose to mannose in the exopolymer synthesized with glucosamine changed from 55±3 : 45±3 to 29±2 : 71±2 and its molecular weight increased from 2.73 x 10^6 to 4.86 x10^6 with culture time. The molar ratio of glucose to mannose in exopolymers ranged from 87±3 : 13±3 to 28±2 : 72±2 and can be controlled by carbon source. On the basis on the results from enzyme hydrolysis of the exopolymers and comparison of ¹H- and ^(13)C-NMR chromatograms, the mannose as a monomeric component is substituted for glucose without changing the structure of pullulan.

Photo-Induced Cytotoxicity of Prodigiosin Analogues

Park, Gyung-Se,Tomlinson, John T.,Misenheimer, Jacob A.,Kucera, Gregory L.,Manderville, Richard A. Korean Chemical Society 2007 Bulletin of the Korean Chemical Society Vol.28 No.1

Prodigiosin (1) is the parent member of a class of polypyrrole natural products that exhibit promising anticancer activities. They can facilitate copper-promoted oxidative DNA damage by binding to copper ions, and this activity is thought to represent their mechanism of cytotoxicity in the dark. They also possess photoinduced cytotoxicity, although 1 is too toxic in the dark to be used effectively for the treatment of cancer by photodynamic therapies. To circumvent dark toxicity by prodigiosins, the semi-synthetic analogue 2, in which the N-pyrrolic atoms of 1 are methylated to block copper coordination, and the synthetic phenyl analogues 3 and 4, which lack the copper-coordinating A-pyrrole ring of 1, were tested for their ability to inhibit colony formation of HL-60 cancer cells in the absence and presence of visible light (λ > 495 nm). Our results show that 2-4 lack cytotoxicity in the dark, but are able to inhibit colony formation of HL-60 cells following irradiation for 30 min. The synthetic derivative 4 exhibits photo-induced cytotoxicity similar to that of the natural product 1, demonstrating the potential use of prodigiosin-based compounds for treatment of cancers following irradiation with visible light.

Photo-Induced Cytotoxicity of Prodigiosin Analogues

Gyungse Park*,John T. Tomlinson,Jacob A. Misenheimer,Gregory L. Kucera,Richard A. Manderville* 대한화학회 2007 Bulletin of the Korean Chemical Society Vol.28 No.1

Prodigiosin (1) is the parent member of a class of polypyrrole natural products that exhibit promising anticancer activities. They can facilitate copper-promoted oxidative DNA damage by binding to copper ions, and this activity is thought to represent their mechanism of cytotoxicity in the dark. They also possess photoinduced cytotoxicity, although 1 is too toxic in the dark to be used effectively for the treatment of cancer by photodynamic therapies. To circumvent dark toxicity by prodigiosins, the semi-synthetic analogue 2, in which the N-pyrrolic atoms of 1 are methylated to block copper coordination, and the synthetic phenyl analogues 3 and 4, which lack the copper-coordinating A-pyrrole ring of 1, were tested for their ability to inhibit colony formation of HL-60 cancer cells in the absence and presence of visible light (l > 495 nm). Our results show that 2-4 lack cytotoxicity in the dark, but are able to inhibit colony formation of HL-60 cells following irradiation for 30 min. The synthetic derivative 4 exhibits photo-induced cytotoxicity similar to that of the natural product 1, demonstrating the potential use of prodigiosin-based compounds for treatment of cancers following irradiation with visible light.