Millimeter-wave, Terahertz, and Infrared Devices

Contains an introduction, reports on two research projects and a list of publications.National Aeronautics and Space Administration Grant NAGW-4691National Science Foundation Grant AST 94-23608U.S. Army Research Office Grant DAAH04-95-1-0610AASERT/U.S. Army Research Office Grant DAAHO4-94-G-0167Hertz Foundation FellowshipU.S. Army Research Laboratory - Federated Laboratories Grant QK-881

High-Frequency (> 100 GHz) and High-Speed (< 10 ps) Electronic Devices

Contains an introduction, reports on four research projects and a list of publications.Defense Advanced Research Projects Agency Contract MDA972-90-C-0021National Aeronautics and Space Administration Grant NAGW-4691National Aeronautics and Space Administration Grant 959705National Science Foundation Grant AST 94-23608National Science Foundation/MRSEC Grant DMR 94-00334MIT Lincoln Laboratory Advanced Concept Program Grant BX-5464U.S. Army Research Office Grant DAAH04-95-1-0610Hertz Foundation FellowshipU.S. Army - Office of Scientific Research Grant DAAH04-94-G-016

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Practical guidelines for rigor and reproducibility in preclinical and clinical studies on cardioprotection

The potential for ischemic preconditioning to reduce infarct size was first recognized more than 30 years ago. Despite extension of the concept to ischemic postconditioning and remote ischemic conditioning and literally thousands of experimental studies in various species and models which identified a multitude of signaling steps, so far there is only a single and very recent study, which has unequivocally translated cardioprotection to improved clinical outcome as the primary endpoint in patients. Many potential reasons for this disappointing lack of clinical translation of cardioprotection have been proposed, including lack of rigor and reproducibility in preclinical studies, and poor design and conduct of clinical trials. There is, however, universal agreement that robust preclinical data are a mandatory prerequisite to initiate a meaningful clinical trial. In this context, it is disconcerting that the CAESAR consortium (Consortium for preclinicAl assESsment of cARdioprotective therapies) in a highly standardized multi-center approach of preclinical studies identified only ischemic preconditioning, but not nitrite or sildenafil, when given as adjunct to reperfusion, to reduce infarct size. However, ischemic preconditioning—due to its very nature—can only be used in elective interventions, and not in acute myocardial infarction. Therefore, better strategies to identify robust and reproducible strategies of cardioprotection, which can subsequently be tested in clinical trials must be developed. We refer to the recent guidelines for experimental models of myocardial ischemia and infarction, and aim to provide now practical guidelines to ensure rigor and reproducibility in preclinical and clinical studies on cardioprotection. In line with the above guideline, we define rigor as standardized state-of-the-art design, conduct and reporting of a study, which is then a prerequisite for reproducibility, i.e. replication of results by another laboratory when performing exactly the same experiment

Class I HDAC inhibition is a novel pathway for regulating astrocytic apoE secretion

<div><p>Despite the important role of apolipoprotein E (apoE) secretion from astrocytes in brain lipid metabolism and the strong association of apoE4, one of the human apoE isoforms, with sporadic and late onset forms of Alzheimer’s disease (AD) little is known about the regulation of astrocytic apoE. Utilizing annotated chemical libraries and a phenotypic screening strategy that measured apoE secretion from a human astrocytoma cell line, inhibition of pan class I histone deacetylases (HDACs) was identified as a mechanism to increase apoE secretion. Knocking down select HDAC family members alone or in combination revealed that inhibition of the class I HDAC family was responsible for enhancing apoE secretion. Knocking down LXRα and LXRβ genes revealed that the increase in astrocytic apoE in response to HDAC inhibition occurred via an LXR-independent pathway. Collectively, these data suggest that pan class I HDAC inhibition is a novel pathway for regulating astrocytic apoE secretion.</p></div

A pan class I HDAC inhibitor increases astrocytic apoE expression and secretion differently from a prototypic pan LXR agonist.

<p>Concentration-dependent effect of MS275 (o) and TO901317 (●), on secreted apoE protein (<i>A</i>) and relative levels of apoE mRNA (<i>B</i>), ABCA1 mRNA (<i>C</i>), LXRα mRNA (<i>D</i>) and LXRβ mRNA (<i>E</i>) in CCF-STTG1 cells. The amount of apoE protein secreted into the media and the relative mRNA levels of apoE, ABCA1, LXRα and LXRβ after compound treatment were normalized to those obtained from vehicle treated controls. The average of GAPDH and 18S mRNA were used as endogenous controls for mRNA normalization. See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0194661#pone.0194661.s010" target="_blank">S3 Table</a> for gene expression assays. TO901317 and MS275 were synthesized at Pfizer and their binding to LXRα (<i>F</i>) and LXRβ (<i>G</i>) was determined using the Lanthascreen assay (Life Technologies). All data are represented as values ±SEM.</p

Pan class I HDAC inhibition increases astrocytic apoE levels.

<p>(<i>A</i>) The number of targets per class and (<i>B</i>) compounds per target class in Pfizer’s annotated chemogenomics library. (<i>C</i>) Number of library compounds resulting in apoE secretion from the CCF-STTG1 human astrocytoma cells following 10 μM treatment for 48 hours. ApoE levels were normalized to those that were obtained following exposure to 2 μM of TO901317. (<i>D</i>) Concentration-dependent increase in apoE secretion from CCF-STTG1 cells following treatment with HDAC inhibitors: MS275 (o), CI994 (●), SAHA (□) and BML-281(■) and TP38 (▲). Data are normalized to vehicle treated cells. (<i>E</i>) Concentration-dependent increase in apoE mRNA levels in CCF-STTG1 cells following exposure to MS275 and CI994. (<i>F</i>) Concentration-dependent increase in ABCA1 mRNA levels following exposure to MS275 and CI994. (See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0194661#pone.0194661.s010" target="_blank">S3 Table</a> for gene expression assays) (G) Concentration-dependent increase in apoE protein secretion from CCF-STTG1 cells following exposure to MS275 and CI994. (<i>H</i>) Concentration-dependent increase in apoE mRNA levels in primary human astrocytes following exposure to MS275 and CI994. (<i>I</i>) Concentration-dependent increase in apoE protein secretion in primary human astrocytes, expressing apoE3/E3 genotype (lot number 18709), following exposure to MS275 and CI994. Data were normalized to vehicle treated cells. Compounds for Fig 1A-D were synthesized at Pfizer. All data are represented as values ± SEM with n = 3, * p<0.05, ** p<0.01, *** <i>p</i><0.001, **** p<0.0001.</p

Pan class I HDAC inhibition increases astrocytic apoE secretion independent of LXR activation.

<p>Specific siRNA oligonucleotides were used to knock down LXRα (αKD) and LXRβ (βKD) either separately or in combination (αβKD) in CCF-STTG1 cells (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0194661#pone.0194661.s009" target="_blank">S2 Table</a> for siRNA oligonucleotides). Concentration-dependent effect of exposure to TO901317 on apoE protein secreted into the media (<i>A</i>); and on apoE mRNA levels (<i>B</i>) upon knocking down LXRα and LXRβ separately or in combination. Concentration-dependent effect of exposure to MS275 on relative apoE protein secreted into the media (<i>C</i>); and on apoE mRNA levels (<i>D</i>) upon knocking down LXRα and LXRβ separately or in combination. Concentration-dependent effect of exposure to TO901317 (<i>E</i>) and MS275 (<i>F</i>) on relative ABCA1 mRNA level upon knocking down LXRα and LXRβ separately and in combination. (<i>G</i>) Concentration-dependent response of apoE protein secreted from primary human astrocytes (lot number 06589) after exposure to MS275 upon knocking down LXRα and LXRβ separately or in combination. For all, levels were normalized to the respective vehicle treated control. See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0194661#pone.0194661.s006" target="_blank">S6 Fig</a> for knock-down efficiencies of LXRα and LXRβ genes and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0194661#pone.0194661.s010" target="_blank">S3 Table</a> for gene expression assays. All data are represented as values ±SEM.</p