ROS mediated selection for increased NADPH availability in Escherichia coli.

Science.gov (United States)

Reynolds, Thomas S; Courtney, Colleen M; Erickson, Keesha E; Wolfe, Lisa M; Chatterjee, Anushree; Nagpal, Prashant; Gill, Ryan T

2017-11-01

The economical production of chemicals and fuels by microbial processes remains an intense area of interest in biotechnology. A key limitation in such efforts concerns the availability of key co-factors, in this case NADPH, required for target pathways. Many of the strategies pursued for increasing NADPH availability in Escherichia coli involve manipulations to the central metabolism, which can create redox imbalances and overall growth defects. In this study we used a reactive oxygen species based selection to search for novel methods of increasing NADPH availability. We report a loss of function mutation in the gene hdfR appears to increase NADPH availability in E. coli. Additionally, we show this excess NADPH can be used to improve the production of 3HP in E. coli. © 2017 Wiley Periodicals, Inc.

Aspergillus fumigatus SidA is a highly specific ornithine hydroxylase with bound flavin cofactor.

Science.gov (United States)

Chocklett, Samuel W; Sobrado, Pablo

2010-08-10

Ferrichrome is a hydroxamate-containing siderophore produced by the pathogenic fungus Aspergillus fumigatus under iron-limiting conditions. This siderophore contains N(5)-hydroxylated l-ornithines essential for iron binding. A. fumigatus siderophore A (Af SidA) catalyzes the flavin- and NADPH-dependent hydroxylation of l-ornithine in ferrichrome biosynthesis. Af SidA was recombinantly expressed and purified as a soluble tetramer and is the first member of this class of flavin monooxygenases to be isolated with a bound flavin cofactor. The enzyme showed typical saturation kinetics with respect to l-ornithine while substrate inhibition was observed at high concentrations of NADPH and NADH. Increasing amounts of hydrogen peroxide were measured as a function of reduced nicotinamide coenzyme concentration, indicating that inhibition was caused by increased uncoupling. Af SidA is highly specific for its amino acid substrate, only hydroxylating l-ornithine. An 8-fold preference in the catalytic efficiency was determined for NADPH compared to NADH. In the absence of substrate, Af SidA can be reduced by NADPH, and a C4a-(hydro)peroxyflavin intermediate is observed. The decay of this intermediate is accelerated by l-ornithine binding. This intermediate was only stabilized by NADPH and not by NADH, suggesting a role for NADP(+) in the stabilization of intermediates in the reaction of Af SidA. NADP(+) is a competitive inhibitor with respect to NADPH, demonstrating that Af SidA forms a ternary complex with NADP(+) and l-ornithine during catalysis. The data suggest that Af SidA likely proceeds by a sequential kinetic mechanism.

A Class I UV-Blocking (senofilcon A) Soft Contact Lens Prevents UVA-induced Yellow Fluorescence and NADH loss in the Rabbit Lens Nucleus in vivo

Science.gov (United States)

Giblin, Frank J.; Lin, Li-Ren; Simpanya, Mukoma F.; Leverenz, Victor R.; Fick, Catherine E.

2012-01-01

It is known that fluorescence, much of it caused by UVA light excitation, increases in the aging human lens, resulting in loss of sharp vision. This study used an in vivo animal model to investigate UVA-excited fluorescence in the rabbit lens, which contains a high level of the UVA chromophore NADH, existing both free and bound to λ-crystallin. Also, the ability of a Class I (senofilcon A) soft contact lens to protect against UVA-induced effects on the rabbit lens was tested. Rabbit eyes were irradiated with UVA light in vivo (100 mW/cm2 on the cornea) for 1 hour using monochromatic 365 nm light. Irradiation was conducted in the presence of either a senofilcon A contact lens, a minimally UV-absorbing lotrafilcon A contact lens, or no contact lens at all. Eyes irradiated without a contact lens showed blue 365 nm-excited fluorescence initially, but this changed to intense yellow fluorescence after 1 hour. Isolated, previously irradiated lenses exhibited yellow fluorescence originating from the lens nucleus when viewed under 365 nm light, but showed normal blue fluorescence arising from the cortex. Previously irradiated lenses also exhibited a faint yellow color when observed under visible light. The senofilcon A contact lens protected completely against the UVA-induced effects on fluorescence and lens yellowing, whereas the lotrafilcon A lens showed no protection. The UVA-exposure also produced a 53% loss of total NADH (free plus bound) in the lens nucleus, with only a 13% drop in the anterior cortex. NADH loss in the nucleus was completely prevented with use of a senofilcon A contact lens, but no significant protection was observed with a lotrafilcon A lens. Overall, the senofilcon A lens provided an average of 67% protection against UVA-induced loss of four pyridine nucleotides in four different regions of the lens. HPLC analysis with fluorescence detection indicated a nearly six-fold increase in 365 nm-excited yellow fluorescence arising from lens nuclear �

Biochemical and molecular characterization of an azoreductase from Staphylococcus aureus, a tetrameric NADPH-dependent flavoprotein

Science.gov (United States)

Chen, Huizhong; Hopper, Sherryll L.; Cerniglia, Carl E.

2018-01-01

Azo dyes are a predominant class of colourants used in tattooing, cosmetics, foods and consumer products. A gene encoding NADPH-flavin azoreductase (Azo1) from the skin bacterium Staphylococcus aureus ATCC 25923 was identified and overexpressed in Escherichia coli. RT-PCR results demonstrated that the azo1 gene was constitutively expressed at the mRNA level in S. aureus. Azo1 was found to be a tetramer with a native molecular mass of 85 kDa containing four non-covalently bound FMN. Azo1 requires NADPH, but not NADH, as an electron donor for its activity. The enzyme was resolved to dimeric apoprotein by removing the flavin prosthetic groups using hydrophobic-interaction chromatography. The dimeric apoprotein was reconstituted on-column and in free stage with FMN, resulting in the formation of a fully functional native-like tetrameric enzyme. The enzyme cleaved the model azo dye 2-[4-(dimethylamino)phenylazo]benzoic acid (Methyl Red) into N,N-dimethyl-p-phenylenediamine and 2-aminobenzoic acid. The apparent Km values for NADPH and Methyl Red substrates were 0·;074 and 0·057 mM, respectively. The apparent Vmax was 0·4 µM min−1 (mg protein)−1. Azo1 was also able to metabolize Orange II, Amaranth, Ponceau BS and Ponceau S azo dyes. Azo1 represents the first azoreductase to be identified and characterized from human skin microflora. PMID:15870453

A Class I UV-blocking (senofilcon A) soft contact lens prevents UVA-induced yellow fluorescence and NADH loss in the rabbit lens nucleus in vivo.

Science.gov (United States)

Giblin, Frank J; Lin, Li-Ren; Simpanya, Mukoma F; Leverenz, Victor R; Fick, Catherine E

2012-09-01

It is known that fluorescence, much of it caused by UVA light excitation, increases in the aging human lens, resulting in loss of sharp vision. This study used an in vivo animal model to investigate UVA-excited fluorescence in the rabbit lens, which contains a high level of the UVA chromophore NADH, existing both free and bound to λ-crystallin. Also, the ability of a Class I (senofilcon A) soft contact lens to protect against UVA-induced effects on the rabbit lens was tested. Rabbit eyes were irradiated with UVA light in vivo (100 mW/cm(2) on the cornea) for 1 h using monochromatic 365 nm light. Irradiation was conducted in the presence of either a senofilcon A contact lens, a minimally UV-absorbing lotrafilcon A contact lens, or no contact lens at all. Eyes irradiated without a contact lens showed blue 365 nm-excited fluorescence initially, but this changed to intense yellow fluorescence after 1 h. Isolated, previously irradiated lenses exhibited yellow fluorescence originating from the lens nucleus when viewed under 365 nm light, but showed normal blue fluorescence arising from the cortex. Previously irradiated lenses also exhibited a faint yellow color when observed under visible light. The senofilcon A contact lens protected completely against the UVA-induced effects on fluorescence and lens yellowing, whereas the lotrafilcon A lens showed no protection. The UVA-exposure also produced a 53% loss of total NADH (free plus bound) in the lens nucleus, with only a 13% drop in the anterior cortex. NADH loss in the nucleus was completely prevented with use of a senofilcon A contact lens, but no significant protection was observed with a lotrafilcon A lens. Overall, the senofilcon A lens provided an average of 67% protection against UVA-induced loss of four pyridine nucleotides in four different regions of the lens. HPLC analysis with fluorescence detection indicated a nearly six-fold increase in 365 nm-excited yellow fluorescence arising from lens nuclear �

Thermodynamic and NMR analyses of NADPH binding to lipocalin-type prostaglandin D synthase

International Nuclear Information System (INIS)

Qin, Shubin; Shimamoto, Shigeru; Maruno, Takahiro; Kobayashi, Yuji; Kawahara, Kazuki; Yoshida, Takuya; Ohkubo, Tadayasu

2015-01-01

Lipocalin-type prostaglandin D synthase (L-PGDS) is one of the most abundant proteins in human cerebrospinal fluid (CSF) with dual functions as a prostaglandin D_2 (PGD_2) synthase and a transporter of lipophilic ligands. Recent studies revealed that L-PGDS plays important roles in protecting against various neuronal diseases induced by reactive oxygen species (ROS). However, the molecular mechanisms of such protective actions of L-PGDS remain unknown. In this study, we conducted thermodynamic and nuclear magnetic resonance (NMR) analyses, and demonstrated that L-PGDS binds to nicotinamide coenzymes, including NADPH, NADP"+, and NADH. Although a hydrophilic ligand is not common for L-PGDS, these ligands, especially NADPH showed specific interaction with L-PGDS at the upper pocket of its ligand-binding cavity with an unusually bifurcated shape. The binding affinity of L-PGDS for NADPH was comparable to that previously reported for NADPH oxidases and NADPH in vitro. These results suggested that L-PGDS potentially attenuates the activities of NADPH oxidases through interaction with NADPH. Given that NADPH is the substrate for NADPH oxidases that play key roles in neuronal cell death by generating excessive ROS, these results imply a novel linkage between L-PGDS and ROS. - Highlights: • Interactions of L-PGDS with nicotinamide coenzymes were studied by ITC and NMR. • The binding affinity of L-PGDS was strongest to NADPH among nicotinamide coenzymes. • NADPH binds to the upper part of L-PGDS ligand-binding cavity. • L-PGDS binds to both lipophilic and hydrophilic ligands. • This study implies a novel linkage between L-PGDS and reactive oxygen species.

Thermodynamic and NMR analyses of NADPH binding to lipocalin-type prostaglandin D synthase

Energy Technology Data Exchange (ETDEWEB)

Qin, Shubin [Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Shimamoto, Shigeru [Faculty of Science and Engineering, Kinki University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502 (Japan); Maruno, Takahiro; Kobayashi, Yuji [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Kawahara, Kazuki; Yoshida, Takuya [Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Ohkubo, Tadayasu, E-mail: ohkubo@phs.osaka-u.ac.jp [Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan)

2015-12-04

Lipocalin-type prostaglandin D synthase (L-PGDS) is one of the most abundant proteins in human cerebrospinal fluid (CSF) with dual functions as a prostaglandin D{sub 2} (PGD{sub 2}) synthase and a transporter of lipophilic ligands. Recent studies revealed that L-PGDS plays important roles in protecting against various neuronal diseases induced by reactive oxygen species (ROS). However, the molecular mechanisms of such protective actions of L-PGDS remain unknown. In this study, we conducted thermodynamic and nuclear magnetic resonance (NMR) analyses, and demonstrated that L-PGDS binds to nicotinamide coenzymes, including NADPH, NADP{sup +}, and NADH. Although a hydrophilic ligand is not common for L-PGDS, these ligands, especially NADPH showed specific interaction with L-PGDS at the upper pocket of its ligand-binding cavity with an unusually bifurcated shape. The binding affinity of L-PGDS for NADPH was comparable to that previously reported for NADPH oxidases and NADPH in vitro. These results suggested that L-PGDS potentially attenuates the activities of NADPH oxidases through interaction with NADPH. Given that NADPH is the substrate for NADPH oxidases that play key roles in neuronal cell death by generating excessive ROS, these results imply a novel linkage between L-PGDS and ROS. - Highlights: • Interactions of L-PGDS with nicotinamide coenzymes were studied by ITC and NMR. • The binding affinity of L-PGDS was strongest to NADPH among nicotinamide coenzymes. • NADPH binds to the upper part of L-PGDS ligand-binding cavity. • L-PGDS binds to both lipophilic and hydrophilic ligands. • This study implies a novel linkage between L-PGDS and reactive oxygen species.

Mitochondrial type II NAD(PH dehydrogenases in fungal cell death

Directory of Open Access Journals (Sweden)

A. Pedro Gonçalves

2015-03-01

Full Text Available During aerobic respiration, cells produce energy through oxidative phosphorylation, which includes a specialized group of multi-subunit complexes in the inner mitochondrial membrane known as the electron transport chain. However, this canonical pathway is branched into single polypeptide alternative routes in some fungi, plants, protists and bacteria. They confer metabolic plasticity, allowing cells to adapt to different environmental conditions and stresses. Type II NAD(PH dehydrogenases (also called alternative NAD(PH dehydrogenases are non-proton pumping enzymes that bypass complex I. Recent evidence points to the involvement of fungal alternative NAD(PH dehydrogenases in the process of programmed cell death, in addition to their action as overflow systems upon oxidative stress. Consistent with this, alternative NAD(PH dehydrogenases are phylogenetically related to cell death - promoting proteins of the apoptosis-inducing factor (AIF-family.

Deciphering the role of NADPH oxidase in complex interactions between maize (Zea mays L.) genotypes and cereal aphids.

Science.gov (United States)

Sytykiewicz, Hubert

2016-07-22

Plant NADPH oxidases (NOXs) encompass a group of membrane-bound enzymes participating in formation of reactive oxygen species (ROS) under physiological conditions as well as in response to environmental stressors. The purpose of the survey was to unveil the role of NADPH oxidase in pro-oxidative responses of maize (Zea mays L.) seedling leaves exposed to cereal aphids' infestation. The impact of apteral females of bird cherry-oat aphid (Rhopalosiphum padi L.) and grain aphid (Sitobion avenae F.) feeding on expression levels of all four NADPH oxidase genes (rbohA, rbohB, rbohC, rbohD) and total activity of NOX enzyme in maize plants were investigated. In addition, inhibitory effect of diphenylene iodonium (DPI) pre-treatment on NOX activity and hydrogen peroxide content in aphid-stressed maize seedlings was studied. Leaf infestation biotests were accomplished on 14-day-old seedlings representing two aphid-resistant varieties (Ambrozja and Waza) and two aphid-susceptible ones (Tasty Sweet and Złota Karłowa). Insects' attack led to profound upregulation of rbohA and rbohD genes in tested host plants, lower elevations were noted in level of rbohB mRNA, whereas abundance of rbohC transcript was not significantly altered. It was uncovered aphid-induced enhancement of NOX activity in examined plants. Higher increases in expression of all investigated rboh genes and activity of NADPH oxidase occurred in tissues of more resistant maize cultivars than in susceptible ones. Furthermore, DPI treatment resulted in strong reduction of NOX activity and H2O2 accumulation in aphid-infested Z. mays plants, thus evidencing circumstantial role of the enzyme in insect-elicited ROS generation. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of near-UV light on Na-K-ATPase of the rat lens

Energy Technology Data Exchange (ETDEWEB)

Torriglia, A.; Zigman, S.

1988-06-01

The influence of in vitro near-UV radiation exposure on the physical state of the rat lens and on its membrane-bound Na-K-ATPase activity was investigated. Lens swelling was correlated to the appearance of opacities and the inactivation of the enzyme. The results show a significant decrease in the Na-K-ATPase activity which may be an early change leading to osmotic type cataracts. The dose-effect curves obtained for cortical and epithelial enzymes were different. Since the data do not follow a mono-exponential function, the existence of two forms of Na-K-ATPase in the lens is discussed.

Detection of membrane-bound and soluble antigens by magnetic levitation

DEFF Research Database (Denmark)

Andersen, Mikkel Schou; Howard, Emily; Lu, Shulin

2017-01-01

blood cell-bound Epstein-Barr viral particles, and soluble IL-6, and validate the results by flow cytometry and immunofluorescence microscopy performed in parallel. Additionally, employing an inexpensive, single lens, manual focus, wifi-enabled camera, we extend the portability of our method for its...

Vitamin C degradation products and pathways in the human lens.

Science.gov (United States)

Nemet, Ina; Monnier, Vincent M

2011-10-28

Vitamin C and its degradation products participate in chemical modifications of proteins in vivo through non-enzymatic glycation (Maillard reaction) and formation of different products called advanced glycation end products. Vitamin C levels are particularly high in selected tissues, such as lens, brain and adrenal gland, and its degradation products can inflict substantial protein damage via formation of advanced glycation end products. However, the pathways of in vivo vitamin C degradation are poorly understood. Here we have determined the levels of vitamin C oxidation and degradation products dehydroascorbic acid, 2,3-diketogulonic acid, 3-deoxythreosone, xylosone, and threosone in the human lens using o-phenylenediamine to trap both free and protein-bound adducts. In the protein-free fraction and water-soluble proteins (WSP), all five listed degradation products were identified. Dehydroascorbic acid, 2,3-diketogulonic acid, and 3-deoxythreosone were the major products in the protein-free fraction, whereas in the WSP, 3-deoxythreosone was the most abundant measured dicarbonyl. In addition, 3-deoxythreosone in WSP showed positive linear correlation with age (p degradation product bound to human lens proteins provides in vivo evidence for the non-oxidative pathway of dehydroascorbate degradation into erythrulose as a major pathway for vitamin C degradation in vivo.

Desbalanço redox: NADPH oxidase como um alvo terapêutico no manejo cardiovascular Desbalance redox: NADPH oxidasa como un objetivo terapéutico en el manejo cardiovascular Redox unbalance: NADPH oxidase as therapeutic target in blood pressure control

Directory of Open Access Journals (Sweden)

Luiza A. Rabêlo

2010-05-01

Full Text Available Vários estudos destacam as espécies reativas de oxigênio e nitrogênio (ERONs como importantes contribuintes na patogênese de numerosas doenças cardiovasculares, incluindo hipertensão, aterosclerose e falência cardíaca. Tais espécies são moléculas altamente bioativas e com vida curta derivadas, principalmente, da redução do oxigênio molecular. O complexo enzimático da NADPH oxidase é a maior fonte dessas espécies reativas na vasculatura. Sob condições fisiológicas, a formação e eliminação destas substâncias aparecem balanceadas na parede vascular. Durante o desbalanço redox, entretanto, há um aumento na atividade da NADPH oxidase e predomínio de agentes pró-oxidantes, superando a capacidade de defesa orgânica antioxidante. Além disso, tal hiperatividade enzimática reduz a biodisponibilidade do óxido nítrico, crucial para a vasodilatação e a manutenção da função vascular normal. Apesar de a NADPH oxidase relacionar-se diretamente à disfunção endotelial, foi primeiramente descrita por sua expressão em fagócitos, onde sua atividade determina a eficácia dos mecanismos de defesa orgânica contra patógenos. As sutis diferenças existentes entre as unidades estruturais das NADPH oxidases, a depender do tipo celular que as expressa, podem ter implicações terapêuticas, permitindo a inibição seletiva do desequilíbrio redox induzido pela NADPH oxidase, sem comprometer, entretanto, sua participação nas vias fisiológicas de sinalização celular que garantem a proteção contra microorganismos.Varios estudios destacan las especies reactivas de oxígeno y nitrógeno (ERON como importantes contribuyentes en la patogénesis de numerosas enfermedades cardiovasculares, incluyendo hipertensión, aterosclerosis y falla cardíaca. Tales especies son moléculas altamente bioactivas y con vida corta derivadas, principalmente, de la reducción del oxígeno molecular. El complejo enzimático de la NADPH oxidasa es

Angiotensin II inhibits the Na+-K+ pump via PKC-dependent activation of NADPH oxidase.

Science.gov (United States)

White, Caroline N; Figtree, Gemma A; Liu, Chia-Chi; Garcia, Alvaro; Hamilton, Elisha J; Chia, Karin K M; Rasmussen, Helge H

2009-04-01

The sarcolemmal Na(+)-K(+) pump, pivotal in cardiac myocyte function, is inhibited by angiotensin II (ANG II). Since ANG II activates NADPH oxidase, we tested the hypothesis that NADPH oxidase mediates the pump inhibition. Exposure to 100 nmol/l ANG II increased superoxide-sensitive fluorescence of isolated rabbit ventricular myocytes. The increase was abolished by pegylated superoxide dismutase (SOD), by the NADPH oxidase inhibitor apocynin, and by myristolated inhibitory peptide to epsilon-protein kinase C (epsilonPKC), previously implicated in ANG II-induced Na(+)-K(+) pump inhibition. A role for epsilonPKC was also supported by an ANG II-induced increase in coimmunoprecipitation of epsilonPKC with the receptor for the activated kinase and with the cytosolic p47(phox) subunit of NADPH oxidase. ANG II decreased electrogenic Na(+)-K(+) pump current in voltage-clamped myocytes. The decrease was abolished by SOD, by the gp91ds inhibitory peptide that blocks assembly and activation of NADPH oxidase, and by epsilonPKC inhibitory peptide. Since colocalization should facilitate NADPH oxidase-dependent regulation of the Na(+)-K(+) pump, we examined whether there is physical association between the pump subunits and NADPH oxidase. The alpha(1)-subunit coimmunoprecipitated with caveolin 3 and with membrane-associated p22(phox) and cytosolic p47(phox) NADPH oxidase subunits at baseline. ANG II had no effect on alpha(1)/caveolin 3 or alpha(1)/p22(phox) interaction, but it increased alpha(1)/p47(phox) coimmunoprecipitation. We conclude that ANG II inhibits the Na(+)-K(+) pump via PKC-dependent NADPH oxidase activation.

The effect of near-UV light on Na-K-ATPase of the rat lens

International Nuclear Information System (INIS)

Torriglia, A.; Zigman, S.

1988-01-01

The influence of in vitro near-UV radiation exposure on the physical state of the rat lens and on its membrane-bound Na-K-ATPase activity was investigated. Lens swelling was correlated to the appearance of opacities and the inactivation of the enzyme. The results show a significant decrease in the Na-K-ATPase activity which may be an early change leading to osmotic type cataracts. The dose-effect curves obtained for cortical and epithelial enzymes were different. Since the data do not follow a mono-exponential function, the existence of two forms of Na-K-ATPase in the lens is discussed. (author)

Human lens colouration, age and cataract

International Nuclear Information System (INIS)

Truscott, R.J.W.; Garner, B.; Hood, B.

1999-01-01

Full text: The human lens biosynthesises UV filter compounds which effectively remove light in the 300-400nm band. These chemicals are present either as an aid to visual acuity, or to filter out damaging UV radiation. The primate UV filters are 3-hydroxykynurenine analogues derived from the metabolism of tryptophan. We have recently demonstrated that these endogenous UV filters are not innocuous, but are in fact capable of binding to proteins, including the crystalline proteins which make up the bulk of the lens. Thus, over time, the levels of protein - bound UV filters increase and this results in the human lens becoming progressively more yellow as we age. This colouration affects our colour vision and it may also be responsible for the brown colour of lenses which is the hallmark of age-related nuclear cataract. An understanding of the intrinsic instability of the endogenous UV filters, combined with changes in the internal transport of these and other small molecular weight compounds including antioxidants, such as glutathione, is allowing us to gain an insight into the processes responsible for the development of age-related cataract: the major cause of world blindness

Single lens to lens duplication: The missing link

OpenAIRE

Bhatt, Rupal; Jethani, Jitendra; Saluja, Praveen; Bharti, Vinay

2008-01-01

Congenital anomalies of the lens include a wide range from lens coloboma to primary aphakia and doubling of lens. There have been few case reports of double lens; the etiology suggested is metaplastic changes in the surface ectoderm that leads to formation of two lens vesicles and hence resulting in double lens. We report a case with bilobed lens, which raises the possibility of explaining the etiology of double lens.

Sex-related differences in NADPH-dependent lipid peroxidation induced by cadmium

Energy Technology Data Exchange (ETDEWEB)

Sato, Masao; Nagai, Yasushi

1986-10-01

Male and female rats were dosed once a day for 2 days with injections of 1.5 mg Cd/kg. Formation of thiobarbituric acid reactive substances (TBA-RS) was significantly increased in male rat liver but not in the females. NADPH-dependent lipid peroxidation in vitro in microsomes derived from untreated rat liver was greater in males than in females. Furthermore, addition of cadmium (Cd) to microsomes isolated from male rat liver produced a dose-dependent potentiation of NADPH-dependent lipid peroxidation from low concentrations of CD. In microsomes derived from females a significant increase in lipid peroxidation was observed only at high Cd concentrations. NADPH-dependent lipid peroxidation enhanced by Cd was greater in the males than in the females. These data suggest that a sex-related difference in the ability of Cd to induce lipid peroxidation in vivo in rat liver appears to be mediated partly through differences in hepatic microsomal NADPH-dependent lipid peroxidation.

Constitutive NADPH-Dependent Electron Transferase Activity of the Nox4 Dehydrogenase Domain?

OpenAIRE

Nisimoto, Yukio; Jackson, Heather M.; Ogawa, Hisamitsu; Kawahara, Tsukasa; Lambeth, J. David

2010-01-01

NADPH oxidase 4 (Nox4) is constitutively active, while Nox2 requires the cytosolic regulatory subunits p47 phox and p67 phox and activated Rac with activation by phorbol 12-myristate 13-acetate (PMA). This study was undertaken to identify the domain on Nox4 that confers constitutive activity. Lysates from Nox4-expressing cells exhibited constitutive NADPH- but not NADH-dependent hydrogen peroxide production with a K m for NADPH of 55 ? 10 ?M. The concentration of Nox4 in cell lysates was esti...

On-field evaluation of operator lens protective devices in interventional radiology

International Nuclear Information System (INIS)

Strocchi, S.; Chiaravalli, A.; Veronese, I.; Novario, R.

2016-01-01

The recent publication of the Euratom Directive 2013/59, adopting the reduction of eye lens dose limits from 150 to 20 mSv y"-"1, calls for the development of new tools and methodologies for evaluating the eye lens dose absorbed by the medical staff involved in interventional radiology practices. Moreover, the effectiveness of the protective devices, like leaded glasses, which can be employed for radiation protection purposes, must be tested under typical exposure scenarios. In this work, eye lens dose measurements were carried out on an anthropomorphic phantom simulating a physician bound to perform standard interventional neuroradiology angiographic procedures. The correlation between eye lens doses, in terms of Hp(0.07), and the equivalent dose [again in terms of Hp(0.07)] monthly measured with thermoluminescent dosemeters placed above the lead apron at the chest level was studied, in the presence and in the absence of different types of leaded glasses. (authors)

Two X-linked chronic granulomatous disease patients with unusual NADPH oxidase properties

NARCIS (Netherlands)

Wolach, Baruch; Broides, Arnon; Zeeli, Tal; Gavrieli, Ronit; de Boer, Martin; van Leeuwen, Karin; Levy, Jacov; Roos, Dirk

2011-01-01

Chronic granulomatous disease (CGD) is an immune deficiency syndrome caused by defects in the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, the enzyme that generates reactive oxygen species (ROS) in phagocytizing leukocytes. This study evaluates the NADPH oxidase capacity in two

Introducing extra NADPH consumption ability significantly increases the photosynthetic efficiency and biomass production of cyanobacteria.

Science.gov (United States)

Zhou, Jie; Zhang, Fuliang; Meng, Hengkai; Zhang, Yanping; Li, Yin

2016-11-01

Increasing photosynthetic efficiency is crucial to increasing biomass production to meet the growing demands for food and energy. Previous theoretical arithmetic analysis suggests that the light reactions and dark reactions are imperfectly coupled due to shortage of ATP supply, or accumulation of NADPH. Here we hypothesized that solely increasing NADPH consumption might improve the coupling of light reactions and dark reactions, thereby increasing the photosynthetic efficiency and biomass production. To test this hypothesis, an NADPH consumption pathway was constructed in cyanobacterium Synechocystis sp. PCC 6803. The resulting extra NADPH-consuming mutant grew much faster and achieved a higher biomass concentration. Analyses of photosynthesis characteristics showed the activities of photosystem II and photosystem I and the light saturation point of the NADPH-consuming mutant all significantly increased. Thus, we demonstrated that introducing extra NADPH consumption ability is a promising strategy to increase photosynthetic efficiency and to enable utilization of high-intensity lights. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Pancreatic Beta-Cell Purification by Altering FAD and NAD(PH Metabolism

Directory of Open Access Journals (Sweden)

P. de Vos

2008-07-01

Full Text Available Isolation of primary beta cells from other cells within in the pancreatic islets is of importance for many fields of islet research. However, up to now, no satisfactory method has been developed that gained high numbers of viable beta cells, without considerable alpha-cell contamination. In this study, we investigated whether rat beta cells can be isolated from nonbeta endocrine cells by manipulating the flavin adenine dinucleotide (FAD and nicotinamide-adenine dinucleotide phosphate (NAD(PH autofluorescence. Beta cells were isolated from dispersed islets by flow cytometry, based on their high FAD and NAD(PH fluorescence. To improve beta cell yield and purity, the cellular FAD and NAD(PH contents were altered by preincubation in culture media containing varying amounts of D-glucose and amino acids. Manipulation of the cellular FAD and NAD(PH fluorescence improves beta cell yield and purity after sorting. This method is also a fast and reliable method to measure beta cell functional viability. A conceivable application is assessing beta cell viability before transplantation.

Engineering an NADPH/NADP⁺ Redox Biosensor in Yeast

DEFF Research Database (Denmark)

Zhang, Jie; Sonnenschein, Nikolaus; Pihl, Thomas Peter Boye

2016-01-01

Genetically encoded biosensors have emerged as powerful tools for timely and precise in vivo evaluation of cellular metabolism. In particular, biosensors that can couple intercellular cues with downstream signaling responses are currently attracting major attention within health science and biote......Genetically encoded biosensors have emerged as powerful tools for timely and precise in vivo evaluation of cellular metabolism. In particular, biosensors that can couple intercellular cues with downstream signaling responses are currently attracting major attention within health science...... in the budding yeast Saccharomyces cerevisiae. Using the biosensor, we are able to monitor the cause of oxidative stress by chemical induction, and changes in NADPH/NADP+ ratios caused by genetic manipulations. Because of the regulatory potential of the biosensor, we also show that the biosensor can actuate upon...... NADPH deficiency by activation of NADPH regeneration. Finally, we couple the biosensor with an expression of dosage-sensitive genes (DSGs) and thereby create a novel tunable sensor-selector useful for synthetic selection of cells with higher NADPH/NADP+ ratios from mixed cell populations. We show...

Blockade of TGF-β 1 Signalling Inhibits Cardiac NADPH Oxidase Overactivity in Hypertensive Rats

Directory of Open Access Journals (Sweden)

José Luis Miguel-Carrasco

2012-01-01

Full Text Available NADPH oxidases constitute a major source of superoxide anion (⋅O2 - in hypertension. Several studies suggest an important role of NADPH oxidases in different effects mediated by TGF-β 1. In this study we show that chronic administration of P144, a peptide synthesized from type III TGF-β 1 receptor, significantly reduced the cardiac NADPH oxidase expression and activity as well as in the nitrotyrosine levels observed in control spontaneously hypertensive rats (V-SHR to levels similar to control normotensive Wistar Kyoto rats. In addition, P144 was also able to reduce the significant increases in the expression of collagen type I protein and mRNA observed in hearts from V-SHR. In addition, positive correlations between collagen expression, NADPH oxidase activity, and nitrotyrosine levels were found in all animals. Finally, TGF-β 1-stimulated Rat-2 exhibited significant increases in NADPH oxidase activity that was inhibited in the presence of P144. It could be concluded that the blockade of TGF-β 1 with P144 inhibited cardiac NADPH oxidase in SHR, thus adding new data to elucidate the involvement of this enzyme in the profibrotic actions of TGF-β 1.

Innervation of the sheep pineal gland by nonsympathetic nerve fibers containing NADPH-diaphorase activity

DEFF Research Database (Denmark)

López-Figueroa, Manuel O.; Ravault, Jean-Paul; Cozzi, Bruno

1997-01-01

Neuroanatomy, NADPH-diaphorase, nitric oxide, innervation, superior cervical ganglionectomy, neuropeptide Y.......Neuroanatomy, NADPH-diaphorase, nitric oxide, innervation, superior cervical ganglionectomy, neuropeptide Y....

Functional heterogeneity of NADPH oxidase-mediated contractions to endothelin with vascular aging.

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Meyer, Matthias R; Barton, Matthias; Prossnitz, Eric R

2014-11-24

Aging, a physiological process and main risk factor for cardiovascular and renal diseases, is associated with endothelial cell dysfunction partly resulting from NADPH oxidase-dependent oxidative stress. Because increased formation of endothelium-derived endothelin-1 (ET-1) may contribute to vascular aging, we studied the role of NADPH oxidase function in age-dependent contractions to ET-1. Renal arteries and abdominal aortas from young and old C57BL6 mice (4 and 24 months of age) were prepared for isometric force measurements. Contractions to ET-1 (0.1-100 nmol/L) were determined in the presence and absence of the NADPH oxidase-selective inhibitor gp91ds-tat (3 μmol/L). To exclude age-dependent differential effects of NO bioactivity between vascular beds, all experiments were conducted in the presence of the NO synthase inhibitor L-NAME (300 μmol/L). In young animals, ET-1-induced contractions were 6-fold stronger in the renal artery than in the aorta (prenal artery and aorta, respectively (pAging had no effect on NADPH oxidase-dependent and -independent contractions to ET-1 in the renal artery. In contrast, contractions to ET-1 were markedly reduced in the aged aorta (5-fold, page-dependent heterogeneity of NADPH oxidase-mediated vascular contractions to ET-1, demonstrating an inherent resistance to functional changes in the renal artery but not in the aorta with aging. Thus, local activity of NADPH oxidase differentially modulates responses to ET-1 with aging in distinct vascular beds. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

Circadian and Metabolic Perspectives in the Role Played by NADPH in Cancer

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Isabel Méndez

2018-03-01

Full Text Available Physiological activity in healthy conditions requires a coordinated interaction between the molecular circadian clock and the network of biochemical pathways. An important metabolic parameter in the interface between these two entities is the redox state. Among the redox coenzymes that regulate the fluxes of enzymatic reactions is the NADP+/NADPH pair. Indeed, the main biosynthetic pathways need NADPH to serve as an electron donor for cellular anabolic transformations. The existence of a metabolic circadian clock is well established, and it was first identified in mammalian red blood cells. The metabolic circadian clock is independent of transcriptional activity and is sustained by the enzymatic complex peroxiredoxin/thioredoxin/NADPH. This complex shows 24-h redox fluctuations metabolizing H2O2 in various tissues and species (fungi, insects, and mammals. Although this NADPH-sensitive metabolic clock is autonomous in erythrocytes that lack a nucleus, it functions in concert with the transcriptional circadian clock in other cell types to accomplish the task of timing cellular physiology. During carcinogenesis, circadian alterations influence cell cycle onset and promote tumoral growth. These alterations also deregulate cellular energetics through a process known as aerobic glycolysis, or the Warburg effect. The Warburg effect is a typical response of cancer cells in which the metabolism turns into glycolysis even in the presence of functional mitochondria. This alteration has been interpreted as a cellular strategy to increase biomass during cancer, and one of its main factors is the availability of NADPH. This minireview explores the potential role of NADPH as a circadian and cancer-promoting metabolite.

Aberration design of zoom lens systems using thick lens modules.

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Zhang, Jinkai; Chen, Xiaobo; Xi, Juntong; Wu, Zhuoqi

2014-12-20

A systematic approach for the aberration design of a zoom lens system using a thick lens module is presented. Each component is treated as a thick lens module at the beginning of the design. A thick lens module refers to a thick lens component with a real lens structure, like lens materials, lens curvatures, lens thicknesses, and lens interval distances. All nine third-order aberrations of a thick lens component are considered during the design. The relationship of component aberrations in different zoom positions can be approximated from the aberration shift. After minimizing the aberrations of the zoom lens system, the nine third-order aberrations of every lens component can be determined. Then the thick lens structure of every lens component can be determined after optimization according to their first-order properties and third-order aberration targets. After a third optimization for minimum practical third-order aberrations of a zoom lens system, the aberration design using the thick lens module is complete, which provides a practical zoom lens system with thick lens structures. A double-sided telecentric zoom lens system is designed using the thick lens module in this paper, which shows that this method is practical for zoom lens design.

Targeting NADPH oxidase decreases oxidative stress in the transgenic sickle cell mouse penis.

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Musicki, Biljana; Liu, Tongyun; Sezen, Sena F; Burnett, Arthur L

2012-08-01

Sickle cell disease (SCD) is a state of chronic vasculopathy characterized by endothelial dysfunction and increased oxidative stress, but the sources and mechanisms responsible for reactive oxygen species (ROS) production in the penis are unknown. We evaluated whether SCD activates NADPH oxidase, induces endothelial nitric oxide synthase (eNOS) uncoupling, and decreases antioxidants in the SCD mouse penis. We further tested the hypothesis that targeting NADPH oxidase decreases oxidative stress in the SCD mouse penis. SCD transgenic (sickle) mice were used as an animal model of SCD. Hemizygous (hemi) mice served as controls. Mice received an NADPH oxidase inhibitor apocynin (10 mM in drinking water) or vehicle. Penes were excised at baseline for molecular studies. Markers of oxidative stress (4-hydroxy-2-nonenal [HNE]), sources of ROS (eNOS uncoupling and NADPH oxidase subunits p67(phox) , p47(phox) , and gp91(phox) ), and enzymatic antioxidants (superoxide dismutase [SOD]1, SOD2, catalase, and glutathione peroxidase-1 [GPx1]) were measured by Western blot in penes. Sources of ROS, oxidative stress, and enzymatic antioxidants in the SCD penis. Relative to hemi mice, SCD increased (Ppenis. Apocynin treatment of sickle mice reversed (P0.05) prevented eNOS uncoupling in the penis. Apocynin treatment of hemi mice did not affect any of these parameters. NADPH oxidase and eNOS uncoupling are sources of oxidative stress in the SCD penis; decreased GPx1 further contributes to oxidative stress. Inhibition of NADPH oxidase upregulation decreases oxidative stress, implying a major role for NADPH oxidase as a ROS source and a potential target for improving vascular function in the SCD mouse penis. © 2012 International Society for Sexual Medicine.

Functional Assembly of Soluble and Membrane Recombinant Proteins of Mammalian NADPH Oxidase Complex.

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Souabni, Hajer; Ezzine, Aymen; Bizouarn, Tania; Baciou, Laura

2017-01-01

Activation of phagocyte cells from an innate immune system is associated with a massive consumption of molecular oxygen to generate highly reactive oxygen species (ROS) as microbial weapons. This is achieved by a multiprotein complex, the so-called NADPH oxidase. The activity of phagocyte NADPH oxidase relies on an assembly of more than five proteins, among them the membrane heterodimer named flavocytochrome b 558 (Cytb 558 ), constituted by the tight association of the gp91 phox (also named Nox2) and p22 phox proteins. The Cytb 558 is the membrane catalytic core of the NADPH oxidase complex, through which the reducing equivalent provided by NADPH is transferred via the associated prosthetic groups (one flavin and two hemes) to reduce dioxygen into superoxide anion. The other major proteins (p47 phox , p67 phox , p40 phox , Rac) requisite for the complex activity are cytosolic proteins. Thus, the NADPH oxidase functioning relies on a synergic multi-partner assembly that in vivo can be hardly studied at the molecular level due to the cell complexity. Thus, a cell-free assay method has been developed to study the NADPH oxidase activity that allows measuring and eventually quantifying the ROS generation based on optical techniques following reduction of cytochrome c. This setup is a valuable tool for the identification of protein interactions, of crucial components and additives for a functional enzyme. Recently, this method was improved by the engineering and the production of a complete recombinant NADPH oxidase complex using the combination of purified proteins expressed in bacterial and yeast host cells. The reconstitution into artificial membrane leads to a fully controllable system that permits fine functional studies.

NADPH-diaphorase expression in the Meibomian glands of rat palpebra in postnatal development

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D. Kluchova

2010-11-01

Full Text Available In the current study, we aimed at investigating the presence of nitric oxide synthase (NOS positive nerve fibers in rat meibomian glands (MGs at various stages of development. There is good evidence to suggest that nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d is a surrogate for neuronal nitric oxide synthase (NOS. Sections of the central, upper eyelids of Wistar rats were processed histochemically for NADPH-d to investigate the presence and distribution of NOS-positive nerve fibers at the following time points: day 1 and weeks 1, 2 and 3 post partum, and in adult controls. At day 1, MG acini were lightly stained and located at a distance from the mucosal border. Vessels were accompanied by intensely stained NADPH-d positive nerve fibers. At the week 1 time point, both the vessels and the NADPH-d positive fibers were still present, but less numerous. MGs were now closer to the mucosa, so that the submucosa was thinner. The acini were mostly pale but occasionally darker. At week 3, there were fewer blood vessels in both the submucosa and within the septa. Darker acini were more common than lightly stained acini. NADPH-d positive dots were observed in the vicinity of the MGs. At the week 3 time point, MGs were adjacent to the mucosal border and stained more intensely than at earlier times; almost all acini were stained. The microscopic appearances were almost identical with those of adult palpebra. Submucosal and septal blood vessels and NADPH-d positive nerve fibers were less numerous. NADPH-d histochemical staining confirmed differences in the density of stained nerve fibers at different developmental stages. The greatest density of NADPH-d -positive nerve fibers occurred in 1-day-old rats whereas they were less numerous in adult rat eyelids. Nerves innervating MGs utilize nitric oxide (NO as a neurotransmitter mostly in early developmental stages and this need thereafter decreases and stabilizes at 3 weeks postnatally.

Dynamic single-cell NAD(P)H measurement reveals oscillatory metabolism throughout the E. coli cell division cycle.

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Zhang, Zheng; Milias-Argeitis, Andreas; Heinemann, Matthias

2018-02-01

Recent work has shown that metabolism between individual bacterial cells in an otherwise isogenetic population can be different. To investigate such heterogeneity, experimental methods to zoom into the metabolism of individual cells are required. To this end, the autofluoresence of the redox cofactors NADH and NADPH offers great potential for single-cell dynamic NAD(P)H measurements. However, NAD(P)H excitation requires UV light, which can cause cell damage. In this work, we developed a method for time-lapse NAD(P)H imaging in single E. coli cells. Our method combines a setup with reduced background emission, UV-enhanced microscopy equipment and optimized exposure settings, overall generating acceptable NAD(P)H signals from single cells, with minimal negative effect on cell growth. Through different experiments, in which we perturb E. coli's redox metabolism, we demonstrated that the acquired fluorescence signal indeed corresponds to NAD(P)H. Using this new method, for the first time, we report that intracellular NAD(P)H levels oscillate along the bacterial cell division cycle. The developed method for dynamic measurement of NAD(P)H in single bacterial cells will be an important tool to zoom into metabolism of individual cells.

Sistema NADPH oxidasa: nuevos retos y perspectivas = NADPH oxidase system: new challenges and perspectives

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Arango Rincón, Julián Camilo

2010-12-01

Full Text Available El sistema NADPH oxidasa es un complejo multiproteico encargado de producir especies reactivas del oxígeno (ROS, por reactive oxygen species en diferentes células y tejidos. Es de gran importancia en las células fagocíticas (principalmente neutrófilos y macrófagos porque participa en la destrucción de microorganismos patógenos, mediante la fagocitosis y la formación de las trampas extracelulares de neutrófilos (NET, por neutrophils extracelular traps, así como en la activación de procesos inflamatorios. Las alteraciones en la producción de ROS por parte de las células fagocíticas a causa de defectos genéticos en los componentes del sistema generan la inmunodeficiencia primaria denominada enfermedad granulomatosa crónica (EGC. Este es un artículo de revisión sobre los componentes del sistema NADPH oxidasa, su distribución celular, mecanismo de activación y acción, así como de las funciones que desempeña en otros tejidos. Además, se revisan los defectos moleculares que llevan a la EGC y el tratamiento de esta, incluyendo la terapia con IFNγ, y finalmente las perspectivas para el estudio del sistema.

Young and Especially Senescent Endothelial Microvesicles Produce NADPH: The Fuel for Their Antioxidant Machinery

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Guillermo Bodega

2018-01-01

Full Text Available In a previous study, we demonstrated that endothelial microvesicles (eMVs have a well-developed enzymatic team involved in reactive oxygen species detoxification. In the present paper, we demonstrate that eMVs can synthesize the reducing power (NAD(PH that nourishes this enzymatic team, especially those eMVs derived from senescent human umbilical vein endothelial cells. Moreover, we have demonstrated that the molecules that nourish the enzymatic machinery involved in NAD(PH synthesis are blood plasma metabolites: lactate, pyruvate, glucose, glycerol, and branched-chain amino acids. Drastic biochemical changes are observed in senescent eMVs to optimize the synthesis of reducing power. Mitochondrial activity is diminished and the glycolytic pathway is modified to increase the activity of the pentose phosphate pathway. Different dehydrogenases involved in NADPH synthesis are also increased. Functional experiments have demonstrated that eMVs can synthesize NADPH. In addition, the existence of NADPH in eMVs was confirmed by mass spectrometry. Multiphoton confocal microscopy images corroborate the synthesis of reducing power in eMVs. In conclusion, our present and previous results demonstrate that eMVs can act as autonomous reactive oxygen species scavengers: they use blood metabolites to synthesize the NADPH that fuels their antioxidant machinery. Moreover, senescent eMVs have a stronger reactive oxygen species scavenging capacity than young eMVs.

Paraquat and maneb co-exposure induces noradrenergic locus coeruleus neurodegeneration through NADPH oxidase-mediated microglial activation

International Nuclear Information System (INIS)

Hou, Liyan; Zhang, Cong; Wang, Ke; Liu, Xiaofang; Wang, Hongwei; Che, Yuning; Sun, Fuqiang; Zhou, Xueying; Zhao, Xiulan; Wang, Qingshan

2017-01-01

Highlights: • Microglial activation induced by paraquat and maneb precedes noradrenergic neurodegeneration in locus coeruleus. • NADPH oxidase activation contributes to microglia-mediated neuroinflammation and related noradrenergic neurodegeneration. • Inhibition of NADPH oxidase by apocynin protects noradrenergic neurons against paraquat and maneb-induced toxicity. - Abstract: Co-exposure to paraquat (PQ) and maneb (Mb) has been shown to increase the risk of Parkinson’s disease (PD) and dopaminergic (DA) neurodegeneration in the substantia nigra pars compacta (SNpc) is observed in PQ and Mb-treated experimental animals. The loss of noradrenergic locus coeruleus (LC/NE) neurons in brainstem is a common feature shared by multiple neurodegenerative diseases, including PD. However, whether PQ and Mb is able to damage LC/NE neurons remains undefined. In this study, mice treated with combined PQ and Mb displayed progressive LC/NE neurodegeneration. Time course studies revealed that the activation of microglia preceded LC/NE neurodegeneration. Mechanistically, the activation of NADPH oxidase contributed to microglial activation and subsequent LC/NE neurodegeneration. We found that PQ and Mb co-exposure induced activation of NADPH oxidase as shown by increased superoxide production and membrane translocation of p47 phox , a cytosolic subunit of NADPH oxidase. Inhibition of NADPH oxidase by apocynin, a widely used NADPH oxidase inhibitor, suppressed microglial activation and gene expressions of proinflammatory factors. Furthermore, reduced activation of nuclear factor-κB (NF-κB) pathway was observed in apocynin-treated mice. More importantly, inhibition of NADPH oxidase by apocynin afforded LC/NE neuroprotection against PQ and Mb-induced neurotoxicity. Thus, our findings revealed the critical role NADPH oxidase-mediated microglial activation in driving LC/NE neurodegeneration induced by PQ and Mb, providing new insights into the pathogenesis of environmental

NADPH- Diaphorase positive cardiac neurons in the atria of mice. A morphoquantitative study

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Castelucci Patrícia

2006-02-01

Full Text Available Abstract Background The present study was conducted to determine the location, the morphology and distribution of NADPH-diaphorase positive neurons in the cardiac nerve plexus of the atria of mice (ASn. This plexus lies over the muscular layer of the atria, dorsal to the muscle itself, in the connective tissue of the subepicardium. NADPH- diaphorase staining was performed on whole-mount preparations of the atria mice. For descriptive purposes, all data are presented as means ± SEM. Results The majority of the NADPH-diaphorase positive neurons were observed in the ganglia of the plexus. A few single neurons were also observed. The number of NADPH-d positive neurons was 57 ± 4 (ranging from 39 to 79 neurons. The ganglion neurons were located in 3 distinct groups: (1 in the region situated cranial to the pulmonary veins, (2 caudally to the pulmonary veins, and (3 in the atrial groove. The largest group of neurons was located cranially to the pulmonary veins (66.7%. Three morphological types of NADPH-diaphorase neurons could be distinguished on the basis of their shape: unipolar cells, bipolar cells and cells with three processes (multipolar cells. The unipolar neurons predominated (78.9%, whereas the multipolar were encountered less frequently (5,3%. The sizes (area of maximal cell profile of the neurons ranged from about 90 μm2to about 220 μm2. Morphometrically, the three types of neurons were similar and there were no significant differences in their sizes. The total number of cardiac neurons (obtained by staining the neurons with NADH-diaphorase method was 530 ± 23. Therefore, the NADPH-diaphorase positive neurons of the heart represent 10% of the number of cardiac neurons stained by NADH. Conclusion The obtained data have shown that the NADPH-d positive neurons in the cardiac plexus of the atria of mice are morphologically different, and therefore, it is possible that the function of the neurons may also be different.

Ultrafine carbon particles promote rotenone-induced dopamine neuronal loss through activating microglial NADPH oxidase

Energy Technology Data Exchange (ETDEWEB)

Wang, Yinxi; Liu, Dan; Zhang, Huifeng; Wang, Yixin [Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, 100191 (China); Wei, Ling [Beijing Center for Physical & Chemical Analysis, Beijing 100089 (China); Liu, Yutong [School of Life Science, Beijing Normal University, Beijing 100875 (China); Liao, Jieying [Department of Translational Medicine, Xiamen Institute of Rare Earth Materials, Chinese Academy of Sciences, Xiamen 361024 (China); Gao, Hui-Ming [Model Animal Research Center of Nanjing University, Nanjing 211800 (China); Zhou, Hui, E-mail: hardhui@gmail.com [Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, 100191 (China)

2017-05-01

Background: Atmospheric ultrafine particles (UFPs) and pesticide rotenone were considered as potential environmental risk factors for Parkinson's disease (PD). However, whether and how UFPs alone and in combination with rotenone affect the pathogenesis of PD remains largely unknown. Methods: Ultrafine carbon black (ufCB, a surrogate of UFPs) and rotenone were used individually or in combination to determine their roles in chronic dopaminergic (DA) loss in neuron-glia, and neuron-enriched, mix-glia cultures. Immunochemistry using antibody against tyrosine hydroxylase was performed to detect DA neuronal loss. Measurement of extracellular superoxide and intracellular reactive oxygen species (ROS) were performed to examine activation of NADPH oxidase. Genetic deletion and pharmacological inhibition of NADPH oxidase and MAC-1 receptor in microglia were employed to examine their role in DA neuronal loss triggered by ufCB and rotenone. Results: In rodent midbrain neuron-glia cultures, ufCB and rotenone alone caused neuronal death in a dose-dependent manner. In particularly, ufCB at doses of 50 and 100 μg/cm{sup 2} induced significant loss of DA neurons. More importantly, nontoxic doses of ufCB (10 μg/cm{sup 2}) and rotenone (2 nM) induced synergistic toxicity to DA neurons. Microglial activation was essential in this process. Furthermore, superoxide production from microglial NADPH oxidase was critical in ufCB/rotenone-induced neurotoxicity. Studies in mix-glia cultures showed that ufCB treatment activated microglial NADPH oxidase to induce superoxide production. Firstly, ufCB enhanced the expression of NADPH oxidase subunits (gp91{sup phox}, p47{sup phox} and p40{sup phox}); secondly, ufCB was recognized by microglial surface MAC-1 receptor and consequently promoted rotenone-induced p47{sup phox} and p67{sup phox} translocation assembling active NADPH oxidase. Conclusion: ufCB and rotenone worked in synergy to activate NADPH oxidase in microglia, leading to

Ultrafine carbon particles promote rotenone-induced dopamine neuronal loss through activating microglial NADPH oxidase

International Nuclear Information System (INIS)

Wang, Yinxi; Liu, Dan; Zhang, Huifeng; Wang, Yixin; Wei, Ling; Liu, Yutong; Liao, Jieying; Gao, Hui-Ming; Zhou, Hui

2017-01-01

Background: Atmospheric ultrafine particles (UFPs) and pesticide rotenone were considered as potential environmental risk factors for Parkinson's disease (PD). However, whether and how UFPs alone and in combination with rotenone affect the pathogenesis of PD remains largely unknown. Methods: Ultrafine carbon black (ufCB, a surrogate of UFPs) and rotenone were used individually or in combination to determine their roles in chronic dopaminergic (DA) loss in neuron-glia, and neuron-enriched, mix-glia cultures. Immunochemistry using antibody against tyrosine hydroxylase was performed to detect DA neuronal loss. Measurement of extracellular superoxide and intracellular reactive oxygen species (ROS) were performed to examine activation of NADPH oxidase. Genetic deletion and pharmacological inhibition of NADPH oxidase and MAC-1 receptor in microglia were employed to examine their role in DA neuronal loss triggered by ufCB and rotenone. Results: In rodent midbrain neuron-glia cultures, ufCB and rotenone alone caused neuronal death in a dose-dependent manner. In particularly, ufCB at doses of 50 and 100 μg/cm 2 induced significant loss of DA neurons. More importantly, nontoxic doses of ufCB (10 μg/cm 2 ) and rotenone (2 nM) induced synergistic toxicity to DA neurons. Microglial activation was essential in this process. Furthermore, superoxide production from microglial NADPH oxidase was critical in ufCB/rotenone-induced neurotoxicity. Studies in mix-glia cultures showed that ufCB treatment activated microglial NADPH oxidase to induce superoxide production. Firstly, ufCB enhanced the expression of NADPH oxidase subunits (gp91 phox , p47 phox and p40 phox ); secondly, ufCB was recognized by microglial surface MAC-1 receptor and consequently promoted rotenone-induced p47 phox and p67 phox translocation assembling active NADPH oxidase. Conclusion: ufCB and rotenone worked in synergy to activate NADPH oxidase in microglia, leading to oxidative damage to DA neurons. Our

Perturbation of human coronary artery endothelial cell redox state and NADPH generation by methylglyoxal.

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Philip E Morgan

Full Text Available Diabetes is associated with elevated plasma glucose, increased reactive aldehyde formation, oxidative damage, and glycation/glycoxidation of biomolecules. Cellular detoxification of, or protection against, such modifications commonly requires NADPH-dependent reducing equivalents (e.g. GSH. We hypothesised that reactive aldehydes may modulate cellular redox status via the inhibition of NADPH-generating enzymes, resulting in decreased thiol and NADPH levels. Primary human coronary artery endothelial cells (HCAEC were incubated with high glucose (25 mM, 24 h, 37°C, or methylglyoxal (MGO, glyoxal, or glycolaldehyde (100-500 µM, 1 h, 37°C, before quantification of intracellular thiols and NADPH-generating enzyme activities. Exposure to MGO, but not the other species examined, significantly (P<0.05 decreased total thiols (∼35%, further experiments with MGO showed significant losses of GSH (∼40% and NADPH (∼10%; these changes did not result in an immediate loss of cell viability. Significantly decreased (∼10% NADPH-producing enzyme activity was observed for HCAEC when glucose-6-phosphate or 2-deoxyglucose-6-phosphate were used as substrates. Cell lysate experiments showed significant MGO-dose dependent inhibition of glucose-6-phosphate-dependent enzymes and isocitrate dehydrogenase, but not malic enzyme. Analysis of intact cell or lysate proteins showed that arginine-derived hydroimidazolones were the predominant advanced glycation end-product (AGE formed; lower levels of N(ε-(carboxyethyllysine (CEL and N(ε-(carboxymethyllysine (CML were also detected. These data support a novel mechanism by which MGO exposure results in changes in redox status in human coronary artery endothelial cells, via inhibition of NADPH-generating enzymes, with resultant changes in reduced protein thiol and GSH levels. These changes may contribute to the endothelial cell dysfunction observed in diabetes-associated atherosclerosis.

Structure of Hordeum vulgare NADPH-dependent thioredoxin reductase 2. Unwinding the reaction mechanism

International Nuclear Information System (INIS)

Kirkensgaard, Kristine G.; Hägglund, Per; Finnie, Christine; Svensson, Birte; Henriksen, Anette

2009-01-01

The first crystal structure of a cereal NTR, a protein involved in seed development and germination, has been determined. The structure is in a conformation that excludes NADPH binding and indicates that a domain reorientation facilitated by Trx binding precedes NADPH binding in the reaction mechanism. Thioredoxins (Trxs) are protein disulfide reductases that regulate the intracellular redox environment and are important for seed germination in plants. Trxs are in turn regulated by NADPH-dependent thioredoxin reductases (NTRs), which provide reducing equivalents to Trx using NADPH to recycle Trxs to the active form. Here, the first crystal structure of a cereal NTR, HvNTR2 from Hordeum vulgare (barley), is presented, which is also the first structure of a monocot plant NTR. The structure was determined at 2.6 Å resolution and refined to an R cryst of 19.0% and an R free of 23.8%. The dimeric protein is structurally similar to the structures of AtNTR-B from Arabidopsis thaliana and other known low-molecular-weight NTRs. However, the relative position of the two NTR cofactor-binding domains, the FAD and the NADPH domains, is not the same. The NADPH domain is rotated by 25° and bent by a 38% closure relative to the FAD domain in comparison with AtNTR-B. The structure may represent an intermediate between the two conformations described previously: the flavin-oxidizing (FO) and the flavin-reducing (FR) conformations. Here, analysis of interdomain contacts as well as phylogenetic studies lead to the proposal of a new reaction scheme in which NTR–Trx interactions mediate the FO to FR transformation

Structure of Hordeum vulgare NADPH-dependent thioredoxin reductase 2. Unwinding the reaction mechanism

Energy Technology Data Exchange (ETDEWEB)

Kirkensgaard, Kristine G. [Carlsberg Laboratory (Denmark); Enzyme and Protein Chemistry, Department of Systems BioIogy, Technical University of Denmark (Denmark); Hägglund, Per; Finnie, Christine; Svensson, Birte [Enzyme and Protein Chemistry, Department of Systems BioIogy, Technical University of Denmark (Denmark); Henriksen, Anette, E-mail: anette@crc.dk [Carlsberg Laboratory (Denmark)

2009-09-01

The first crystal structure of a cereal NTR, a protein involved in seed development and germination, has been determined. The structure is in a conformation that excludes NADPH binding and indicates that a domain reorientation facilitated by Trx binding precedes NADPH binding in the reaction mechanism. Thioredoxins (Trxs) are protein disulfide reductases that regulate the intracellular redox environment and are important for seed germination in plants. Trxs are in turn regulated by NADPH-dependent thioredoxin reductases (NTRs), which provide reducing equivalents to Trx using NADPH to recycle Trxs to the active form. Here, the first crystal structure of a cereal NTR, HvNTR2 from Hordeum vulgare (barley), is presented, which is also the first structure of a monocot plant NTR. The structure was determined at 2.6 Å resolution and refined to an R{sub cryst} of 19.0% and an R{sub free} of 23.8%. The dimeric protein is structurally similar to the structures of AtNTR-B from Arabidopsis thaliana and other known low-molecular-weight NTRs. However, the relative position of the two NTR cofactor-binding domains, the FAD and the NADPH domains, is not the same. The NADPH domain is rotated by 25° and bent by a 38% closure relative to the FAD domain in comparison with AtNTR-B. The structure may represent an intermediate between the two conformations described previously: the flavin-oxidizing (FO) and the flavin-reducing (FR) conformations. Here, analysis of interdomain contacts as well as phylogenetic studies lead to the proposal of a new reaction scheme in which NTR–Trx interactions mediate the FO to FR transformation.

Dual utilization of NADPH and NADH cofactors enhances xylitol production in engineered Saccharomyces cerevisiae.

Science.gov (United States)

Jo, Jung-Hyun; Oh, Sun-Young; Lee, Hyeun-Soo; Park, Yong-Cheol; Seo, Jin-Ho

2015-12-01

Xylitol, a natural sweetener, can be produced by hydrogenation of xylose in hemicelluloses. In microbial processes, utilization of only NADPH cofactor limited commercialization of xylitol biosynthesis. To overcome this drawback, Saccharomyces cerevisiae D452-2 was engineered to express two types of xylose reductase (XR) with either NADPH-dependence or NADH-preference. Engineered S. cerevisiae DWM expressing both the XRs exhibited higher xylitol productivity than the yeast strain expressing NADPH-dependent XR only (DWW) in both batch and glucose-limited fed-batch cultures. Furthermore, the coexpression of S. cerevisiae ZWF1 and ACS1 genes in the DWM strain increased intracellular concentrations of NADPH and NADH and improved maximum xylitol productivity by 17%, relative to that for the DWM strain. Finally, the optimized fed-batch fermentation of S. cerevisiae DWM-ZWF1-ACS1 resulted in 196.2 g/L xylitol concentration, 4.27 g/L h productivity and almost the theoretical yield. Expression of the two types of XR utilizing both NADPH and NADH is a promising strategy to meet the industrial demands for microbial xylitol production. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lens stem cells may reside outside the lens capsule: an hypothesis

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Meyer Rita A

2007-06-01

Full Text Available Abstract In this paper, we consider the ocular lens in the context of contemporary developments in biological ideas. We attempt to reconcile lens biology with stem cell concepts and a dearth of lens tumors. Historically, the lens has been viewed as a closed system, in which cells at the periphery of the lens epithelium differentiate into fiber cells. Theoretical considerations led us to question whether the intracapsular lens is indeed self-contained. Since stem cells generate tumors and the lens does not naturally develop tumors, we reasoned that lens stem cells may not be present within the capsule. We hypothesize that lens stem cells reside outside the lens capsule, in the nearby ciliary body. Our ideas challenge the existing lens biology paradigm. We begin our discussion with lens background information, in order to describe our lens stem cell hypothesis in the context of published data. Then we present the ciliary body as a possible source for lens stem cells, and conclude by comparing the ocular lens with the corneal epithelium.

[The distribution of NADPH-diaphorase and neuronal no synthase in rat medulla oblongata nuclei].

Science.gov (United States)

Chertok, V M; Kotsuba, A E

2013-01-01

The distribution of nitroxide ergic neurons in the medulla oblongata nuclei in Wistar rats (n = 8) was studied histochemically (NADPH-diaphorase) and using immunohistochemistry with an antiserum against neuronal form of nitric oxide synthase (nNOS). NADPH-diaphorase activity was found in large and small neurons of the sensory, autonomic and motor nuclei. The latter were especially rich in the cells demonstrating the activity of the enzyme. Unlike NADPH-diaphorase, nNOS in the corresponding nuclei was always detected in the fewer number of neurons, predominantly of small sizes. The sensory nuclei (nucleus of solitary tract, reticular parvocellular and lateral nuclei, spinal nucleus of the trigeminal nerve) contained 1.5-3 times more nNOS neurons than in motor nuclei. In some nuclei (nucleus ambiguus, hypoglossal nerve nucleus), containing numerous NADPH-diaphorase-positive neurons, immunoreactive cells were particularly rare.

Depletion of NADP(H) due to CD38 activation triggers endothelial dysfunction in the postischemic heart.

Science.gov (United States)

Reyes, Levy A; Boslett, James; Varadharaj, Saradhadevi; De Pascali, Francesco; Hemann, Craig; Druhan, Lawrence J; Ambrosio, Giuseppe; El-Mahdy, Mohamed; Zweier, Jay L

2015-09-15

In the postischemic heart, coronary vasodilation is impaired due to loss of endothelial nitric oxide synthase (eNOS) function. Although the eNOS cofactor tetrahydrobiopterin (BH4) is depleted, its repletion only partially restores eNOS-mediated coronary vasodilation, indicating that other critical factors trigger endothelial dysfunction. Therefore, studies were performed to characterize the unidentified factor(s) that trigger endothelial dysfunction in the postischemic heart. We observed that depletion of the eNOS substrate NADPH occurs in the postischemic heart with near total depletion from the endothelium, triggering impaired eNOS function and limiting BH4 rescue through NADPH-dependent salvage pathways. In isolated rat hearts subjected to 30 min of ischemia and reperfusion (I/R), depletion of the NADP(H) pool occurred and was most marked in the endothelium, with >85% depletion. Repletion of NADPH after I/R increased NOS-dependent coronary flow well above that with BH4 alone. With combined NADPH and BH4 repletion, full restoration of NOS-dependent coronary flow occurred. Profound endothelial NADPH depletion was identified to be due to marked activation of the NAD(P)ase-activity of CD38 and could be prevented by inhibition or specific knockdown of this protein. Depletion of the NADPH precursor, NADP(+), coincided with formation of 2'-phospho-ADP ribose, a CD38-derived signaling molecule. Inhibition of CD38 prevented NADP(H) depletion and preserved endothelium-dependent relaxation and NO generation with increased recovery of contractile function and decreased infarction in the postischemic heart. Thus, CD38 activation is an important cause of postischemic endothelial dysfunction and presents a novel therapeutic target for prevention of this dysfunction in unstable coronary syndromes.

OBSERVATIONAL UPPER BOUND ON THE COSMIC ABUNDANCES OF NEGATIVE-MASS COMPACT OBJECTS AND ELLIS WORMHOLES FROM THE SLOAN DIGITAL SKY SURVEY QUASAR LENS SEARCH

Energy Technology Data Exchange (ETDEWEB)

Takahashi, Ryuichi; Asada, Hideki [Faculty of Science and Technology, Hirosaki University, Hirosaki 036-8561 (Japan)

2013-05-01

The latest result in the Sloan Digital Sky Survey Quasar Lens Search (SQLS) has set the first cosmological constraints on negative-mass compact objects and Ellis wormholes. There are no multiple images lensed by the above two exotic objects for {approx}50, 000 distant quasars in the SQLS data. Therefore, an upper bound is put on the cosmic abundances of these lenses. The number density of negative-mass compact objects is n < 10{sup -8}(10{sup -4}) h {sup 3} Mpc{sup -3} at the mass scale |M| > 10{sup 15}(10{sup 12}) M{sub Sun }, which corresponds to the cosmological density parameter |{Omega}| < 10{sup -4} at the galaxy and cluster mass range |M| = 10{sup 12-15} M{sub Sun }. The number density of the Ellis wormhole is n < 10{sup -4} h {sup 3} Mpc{sup -3} for a range of the throat radius a = 10-10{sup 4} pc, which is much smaller than the Einstein ring radius.

Constitutive NADPH-dependent electron transferase activity of the Nox4 dehydrogenase domain.

Science.gov (United States)

Nisimoto, Yukio; Jackson, Heather M; Ogawa, Hisamitsu; Kawahara, Tsukasa; Lambeth, J David

2010-03-23

NADPH oxidase 4 (Nox4) is constitutively active, while Nox2 requires the cytosolic regulatory subunits p47(phox) and p67(phox) and activated Rac with activation by phorbol 12-myristate 13-acetate (PMA). This study was undertaken to identify the domain on Nox4 that confers constitutive activity. Lysates from Nox4-expressing cells exhibited constitutive NADPH- but not NADH-dependent hydrogen peroxide production with a K(m) for NADPH of 55 +/- 10 microM. The concentration of Nox4 in cell lysates was estimated using Western blotting and allowed calculation of a turnover of approximately 200 mol of H(2)O(2) min(-1) (mol of Nox4)(-1). A chimeric protein (Nox2/4) consisting of the Nox2 transmembrane (TM) domain and the Nox4 dehydrogenase (DH) domain showed H(2)O(2) production in the absence of cytosolic regulatory subunits. In contrast, chimera Nox4/2, consisting of the Nox4 TM and Nox2 DH domains, exhibited PMA-dependent activation that required coexpression of regulatory subunits. Nox DH domains from several Nox isoforms were purified and evaluated for their electron transferase activities. Nox1 DH, Nox2 DH, and Nox5 DH domains exhibited barely detectable activities toward artificial electron acceptors, while the Nox4 DH domain exhibited significant rates of reduction of cytochrome c (160 min(-1), largely superoxide dismutase-independent), ferricyanide (470 min(-1)), and other electron acceptors (artificial dyes and cytochrome b(5)). Rates were similar to those observed for H(2)O(2) production by the Nox4 holoenzyme in cell lysates. The activity required added FAD and was seen with NADPH but not NADH. These results indicate that the Nox4 DH domain exists in an intrinsically activated state and that electron transfer from NADPH to FAD is likely to be rate-limiting in the NADPH-dependent reduction of oxygen by holo-Nox4.

NADPH oxidases as novel pharmacologic targets against influenza A virus infection.

Science.gov (United States)

Vlahos, Ross; Selemidis, Stavros

2014-12-01

Influenza A viruses represent a major global health care challenge, with imminent pandemics, emerging antiviral resistance, and long lag times for vaccine development, raising a pressing need for novel pharmacologic strategies that ideally target the pathology irrespective of the infecting strain. Reactive oxygen species (ROS) pervade all facets of cell biology with both detrimental and protective properties. Indeed, there is compelling evidence that activation of the NADPH oxidase 2 (NOX2) isoform of the NADPH oxidase family of ROS-producing enzymes promotes lung oxidative stress, inflammation, injury, and dysfunction resulting from influenza A viruses of low to high pathogenicity, as well as impeding virus clearance. By contrast, the dual oxidase isoforms produce ROS that provide vital protective antiviral effects for the host. In this review, we propose that inhibitors of NOX2 are better alternatives than broad-spectrum antioxidant approaches for treatment of influenza pathologies, for which clinical efficacy may have been limited owing to poor bioavailability and inadvertent removal of beneficial ROS. Finally, we briefly describe the current suite of NADPH oxidase inhibitors and the molecular features of the NADPH oxidase enzymes that could be exploited by drug discovery for development of more specific and novel inhibitors to prevent or treat disease caused by influenza. Copyright © 2014 by The American Society for Pharmacology and Experimental Therapeutics.

Peroxidasin-mediated crosslinking of collagen IV is independent of NADPH oxidases

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Gábor Sirokmány

2018-06-01

Full Text Available Collagen IV is a major component of the basement membrane in epithelial tissues. The NC1 domains of collagen IV protomers are covalently linked together through sulfilimine bonds, the formation of which is catalyzed by peroxidasin. Although hydrogen peroxide is essential for this reaction, the exact source of the oxidant remains elusive. Members of the NOX/DUOX NADPH oxidase family are specifically devoted to the production of superoxide and hydrogen peroxide. Our aim in this study was to find out if NADPH oxidases contribute in vivo to the formation of collagen IV sulfilimine crosslinks. We used multiple genetically modified in vivo model systems to provide a detailed assessment of this question. Our data indicate that in various peroxidasin-expressing tissues sulfilimine crosslinks between the NC1 domains of collagen IV can be readily detected in the absence of functioning NADPH oxidases. We also analyzed how subatmospheric oxygen levels influence the collagen IV network in collagen-producing cultured cells with rapid matrix turnover. We showed that collagen IV crosslinks remain intact even under strongly hypoxic conditions. Our hypothesis is that during collagen IV network formation PXDN cooperates with a NOX/DUOX-independent H2O2 source that is functional also at very low ambient oxygen levels. Keywords: Peroxidasin, NADPH oxidase, Hydrogen peroxide, Collagen IV, Sulfilimine

Resveratrol protects vascular endothelial cells from high glucose-induced apoptosis through inhibition of NADPH oxidase activation-driven oxidative stress.

Science.gov (United States)

Chen, Feng; Qian, Li-Hua; Deng, Bo; Liu, Zhi-Min; Zhao, Ying; Le, Ying-Ying

2013-09-01

Hyperglycemia-induced oxidative stress has been implicated in diabetic vascular complications in which NADPH oxidase is a major source of reactive oxygen species (ROS) generation. Resveratrol is a naturally occurring polyphenol, which has vasoprotective effects in diabetic animal models and inhibits high glucose (HG)-induced oxidative stress in endothelial cells. We aimed to examine whether HG-induced NADPH oxidase activation and ROS production contribute to glucotoxicity to endothelial cells and the effect of resveratrol on glucotoxicity. Using a murine brain microvascular endothelial cell line bEnd3, we found that NADPH oxidase inhibitor (apocynin) and resveratrol both inhibited HG-induced endothelial cell apoptosis. HG-induced elevation of NADPH oxidase activity and production of ROS were inhibited by apocynin, suggesting that HG induces endothelial cell apoptosis through NADPH oxidase-mediated ROS production. Mechanistic studies revealed that HG upregulated NADPH oxidase subunit Nox1 but not Nox2, Nox4, and p22(phox) expression through NF-κB activation, which resulted in elevation of NADPH oxidase activity and consequent ROS production. Resveratrol prevented HG-induced endothelial cell apoptosis through inhibiting HG-induced NF-κB activation, NADPH oxidase activity elevation, and ROS production. HG induces endothelial cell apoptosis through NF-κB/NADPH oxidase/ROS pathway, which was inhibited by resveratrol. Our findings provide new potential therapeutic targets against brain vascular complications of diabetes. © 2013 John Wiley & Sons Ltd.

Changes in the distribution of lens calcium during development of x-ray cataract

International Nuclear Information System (INIS)

Hightower, K.R.; Giblin, F.J.; Reddy, V.N.

1983-01-01

The present study was designed to examine the possible role of calcium in the opacification of x-ray-induced cataract in rabbit. The results demonstrate that the concentration of calcium in x-rayed lenses, just prior to lens hydration (7.5 weeks postirradiation), was twice that present in contralateral control lenses. At this stage of immature cataract, the lens nucleus remained transparent and maintained a normal level of calcium, but the lens cortex, containing regions of subcapsular opacification, accumulated a level of calcium that was twice that of the control. In the completely opaque mature cataract, (8-9 weeks post x-ray), both the cortex and nucleus had gained significant amounts of calcium. As the concentration of total calcium increased in the immature x-ray cataract, the amount of the cation bound to membranes and insoluble proteins of the cytosol also increased comparably. However, the relative proportion of calcium in the various fractions remained unaltered in the immature cataract; in both control lenses and immature cataracts, 20% of the total calcium remained in the membrane pellet and 70% was located in the soluble protein fraction. Only in the mature stage of cataract was a shift in the distribution of calcium apparent, as the proportion of calcium in the soluble protein fraction increased to 90%. Although only 7% of the total calcium in a mature cataract was bound to membrane, the amount represented a fivefold increase over the control. The results of this study demonstrate that an elevation in lens calcium accompanies the opacification process in x-ray cataract. The work also suggests that changes in calcium levels are not likely to result from inactivation of Ca-ATPase

Interrupted reperfusion reduces the activation of NADPH oxidase after cerebral I/R injury.

Science.gov (United States)

Shen, Jia; Bai, Xiao-Yin; Qin, Yuan; Jin, Wei-Wei; Zhou, Jing-Yin; Zhou, Ji-Ping; Yan, Ying-Gang; Wang, Qiong; Bruce, Iain C; Chen, Jiang-Hua; Xia, Qiang

2011-06-15

Interrupted reperfusion reduces ischemia/reperfusion (I/R) injury. This study was designed to determine whether NADPH oxidase participates in the neural protection against global I/R injury after interrupted reperfusion. Mice were randomly divided into five groups: sham (sham-operated), I/R (20-min global I/R), RR (I/R+interrupted reperfusion), Apo (I/R+apocynin administration), and RR+Apo. Behavioral tests (pole test, beam walking, and Morris water maze) and Nissl staining were undertaken in all five groups; superoxide levels, expression of gp91(phox) and p47(phox), p47(phox) translocation, and Rac1 activation were measured in the sham, I/R, and RR groups. The motor coordination, bradykinesia, and spatial learning and memory, as well as the neuron survival rates, were better in the RR, Apo, and RR+Apo groups than in the I/R group. The NADPH oxidase-dependent superoxide levels, p47(phox) and gp91(phox) expression, p47(phox) translocation, and Rac1 activation were lower in the RR group than in the I/R group. In conclusion, the neural protective effect of interrupted reperfusion is at least partly mediated by decreasing the expression and assembly of NADPH oxidase and the levels of NADPH oxidase-derived superoxide. The most striking reduction Rac1-GTP in the RR group suggests that interrupted reperfusion also acts on the activation of assembled NADPH oxidase by reducing the availability of Rac1-GTP. Copyright © 2011 Elsevier Inc. All rights reserved.

The NADPH thioredoxin reductase C functions as an electron donor to 2-Cys peroxiredoxin in a thermophilic cyanobacterium Thermosynechococcus elongatus BP-1

International Nuclear Information System (INIS)

Sueoka, Keigo; Yamazaki, Teruaki; Hiyama, Tetsuo; Nakamoto, Hitoshi

2009-01-01

An NADPH thioredoxin reductase C was co-purified with a 2-Cys peroxiredoxin by the combination of anion exchange chromatography and electroelution from gel slices after native PAGE from a thermophilic cyanobacterium Thermosynechococcus elongatus as an NAD(P)H oxidase complex induced by oxidative stress. The result provided a strong evidence that the NADPH thioredoxin reductase C interacts with the 2-Cys peroxiredoxin in vivo. An in vitro reconstitution assay with purified recombinant proteins revealed that both proteins were essential for an NADPH-dependent reduction of H 2 O 2 . These results suggest that the reductase transfers the reducing power from NADPH to the peroxiredoxin, which reduces peroxides in the cyanobacterium under oxidative stress. In contrast with other NADPH thioredoxin reductases, the NADPH thioredoxin reductase C contains a thioredoxin-like domain in addition to an NADPH thioredoxin reductase domain in the same polypeptide. Each domain contains a conserved CXYC motif. A point mutation at the CXYC motif in the NADPH thioredoxin reductase domain resulted in loss of the NADPH oxidation activity, while a mutation at the CXYC motif in the thioredoxin-like domain did not affect the electron transfer, indicating that this motif is not essential in the electron transport from NADPH to the 2-Cys peroxiredoxin.

Crystal structure of conjugated polyketone reductase (CPR-C1) from Candida parapsilosis IFO 0708 complexed with NADPH.

Science.gov (United States)

Qin, Hui-Min; Yamamura, Akihiro; Miyakawa, Takuya; Kataoka, Michihiko; Maruoka, Shintaro; Ohtsuka, Jun; Nagata, Koji; Shimizu, Sakayu; Tanokura, Masaru

2013-11-01

Conjugated polyketone reductase (CPR-C1) from Candida parapsilosis IFO 0708 is a member of the aldo-keto reductase (AKR) superfamily and reduces ketopantoyl lactone to d-pantoyl lactone in a NADPH-dependent and stereospecific manner. We determined the crystal structure of CPR-C1.NADPH complex at 2.20 Å resolution. CPR-C1 adopted a triose-phosphate isomerase (TIM) barrel fold at the core of the structure in which Thr25 and Lys26 of the GXGTX motif bind uniquely to the adenosine 2'-phosphate group of NADPH. This finding provides a novel structural basis for NADPH binding of the AKR superfamily. Copyright © 2013 Wiley Periodicals, Inc.

A Correlation of Thin Lens Approximation to Thick Lens Design by Using Coddington Factors in Lens Design and Manufacturing

OpenAIRE

FARSAKOĞLU, Ö. Faruk

2014-01-01

The effect of Coddington factors on aberration functions has been analysed using thin lens approximation. Minimizing spherical aberrations of singlet lenses using Coddington factors in lens design depending on lens manufacturing is discussed. Notation of lens test plate pairs used in lens manufacturing is also presented in terms of Coddington shape factors.

The role of oxidative stress and NADPH oxidase in the pathogenesis of atherosclerosis

Directory of Open Access Journals (Sweden)

Dorota Bryk

2017-01-01

Full Text Available Reactive oxygen species (ROS play a key role in the pathogenesis of atherosclerosis. The main mechanisms which are involved are low-density lipoprotein oxidative modification, inactivation of nitric oxide and modulation of redox-sensitive signaling pathways. ROS contribute to several aspects of atherosclerosis including endothelial cell dysfunction, monocyte/macrophage recruitment and activation, stimulation of inflammation, and inducing smooth muscle cell migration and proliferation. NADPH oxidase is the main source of ROS in the vasculature. This enzyme consists of a membrane-bound heterodimer of gp91phox and p22phox, cytosolic regulatory subunits p47phox, p67phox and p40phox, and small GTP-binding proteins rac1 and rac 2. Seven distinct isoforms of this enzyme have been identified, of which four (NOX1, 2, 4 and 5 may have cardiovascular function. In this paper, we review the current state of knowledge concerning the role of oxidative stress and NOX enzymes in pathogenesis of atherosclerosis. Moreover, we analyze the experimental studies that explore the relationship between the NOX family and atherosclerosis.

Ozone affects pollen viability and NAD(P)H oxidase release from Ambrosia artemisiifolia pollen

International Nuclear Information System (INIS)

Pasqualini, Stefania; Tedeschini, Emma; Frenguelli, Giuseppe; Wopfner, Nicole; Ferreira, Fatima; D'Amato, Gennaro; Ederli, Luisa

2011-01-01

Air pollution is frequently proposed as a cause of the increased incidence of allergy in industrialised countries. We investigated the impact of ozone (O 3 ) on reactive oxygen species (ROS) and allergen content of ragweed pollen (Ambrosia artemisiifolia). Pollen was exposed to acute O 3 fumigation, with analysis of pollen viability, ROS and nitric oxide (NO) content, activity of nicotinamide adenine dinucleotide phosphate (NAD[P]H) oxidase, and expression of major allergens. There was decreased pollen viability after O 3 fumigation, which indicates damage to the pollen membrane system, although the ROS and NO contents were not changed or were only slightly induced, respectively. Ozone exposure induced a significant enhancement of the ROS-generating enzyme NAD(P)H oxidase. The expression of the allergen Amb a 1 was not affected by O 3 , determined from the mRNA levels of the major allergens. We conclude that O 3 can increase ragweed pollen allergenicity through stimulation of ROS-generating NAD(P)H oxidase. - Highlights: → O 3 reduces the viability of ragweed pollen. → ROS and allergens of ragweed pollen were not affected by O 3 exposure. → O 3 enhances the activity of the ROS-generating enzyme NAD(P)H oxidase. → O 3 increases ragweed pollen allergenicity through NAD(P)H-oxidase stimulation. - This study focuses on the effects of the atmospheric pollutant ozone on ROS content and NAD(P)H oxidase activity of ragweed pollen grains.

Ozone affects pollen viability and NAD(P)H oxidase release from Ambrosia artemisiifolia pollen

Energy Technology Data Exchange (ETDEWEB)

Pasqualini, Stefania, E-mail: spas@unipg.it [Department of Applied Biology, University of Perugia, Perugia (Italy); Tedeschini, Emma; Frenguelli, Giuseppe [Department of Applied Biology, University of Perugia, Perugia (Italy); Wopfner, Nicole; Ferreira, Fatima [Department of Molecular Biology, CD Laboratory for Allergy Diagnosis and Therapy, University of Salzburg, Salzburg (Austria); D' Amato, Gennaro [Division of Respiratory and Allergic Diseases, ' A. Cardarelli' High Speciality Hospital, Naples (Italy); Ederli, Luisa [Department of Applied Biology, University of Perugia, Perugia (Italy)

2011-10-15

Air pollution is frequently proposed as a cause of the increased incidence of allergy in industrialised countries. We investigated the impact of ozone (O{sub 3}) on reactive oxygen species (ROS) and allergen content of ragweed pollen (Ambrosia artemisiifolia). Pollen was exposed to acute O{sub 3} fumigation, with analysis of pollen viability, ROS and nitric oxide (NO) content, activity of nicotinamide adenine dinucleotide phosphate (NAD[P]H) oxidase, and expression of major allergens. There was decreased pollen viability after O{sub 3} fumigation, which indicates damage to the pollen membrane system, although the ROS and NO contents were not changed or were only slightly induced, respectively. Ozone exposure induced a significant enhancement of the ROS-generating enzyme NAD(P)H oxidase. The expression of the allergen Amb a 1 was not affected by O{sub 3}, determined from the mRNA levels of the major allergens. We conclude that O{sub 3} can increase ragweed pollen allergenicity through stimulation of ROS-generating NAD(P)H oxidase. - Highlights: > O{sub 3} reduces the viability of ragweed pollen. > ROS and allergens of ragweed pollen were not affected by O{sub 3} exposure. > O{sub 3} enhances the activity of the ROS-generating enzyme NAD(P)H oxidase. > O{sub 3} increases ragweed pollen allergenicity through NAD(P)H-oxidase stimulation. - This study focuses on the effects of the atmospheric pollutant ozone on ROS content and NAD(P)H oxidase activity of ragweed pollen grains.

NADPH-d activity in rat thymus after the application of retinoid acid

Directory of Open Access Journals (Sweden)

F. Dorko

2012-02-01

Full Text Available The aim of this work was to determine the localization of nicotinamide-adenine dinucleotide phosphate-diaphorase (NADPH-d activity as the marker for synthesis of nitric oxide synthase (NOS in the rat thymus after the application of retinoid acid (RA on 1st, 7th, 14th and 21st days of gestation. The given results can build the basis for understanding of the role of NOS in rat thymus. NADPH-d positive cells were represented with dark-blue color and were localized on corticomedullar junction of the thymus. These cells were of different intensity of coloring and were shaped in oval, circle or irregular forms. NADPH-d positive nerve fibers were observed in perivascular topography. They were marked more strongly in the case of control group. The result of application of RA to gravid rats was that the birth weights of newborn rats and their thymuses were smaller, but without statistically significance.

Immunohistochemical studies of lens crystallins in the dysgenetic lens (dyl) mutant mice

NARCIS (Netherlands)

Brahma, S.K.; Sanyal, S.

1984-01-01

The lens in the dyl mutant mice shows a persistent lens-ectodermal connection as well as degeneration and extrusion of lens materials after the initial differentiation of the fibres. Immunohistochemical investigation of the ontogeny of the lens crystallins in this developing mutant lens has been

Scattered radiation risk to the lens of the eyes for staff involved in using mobile C-arm fluoroscopy unit: Which position is riskiest?

Energy Technology Data Exchange (ETDEWEB)

Salleh, H.; Matori, M. K.; Isa, M. J. M. [Agensi Nuklear Malaysia, Bangi, 43000 Kajang, Selangor (Malaysia); Samat, S. B. [Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

2015-09-25

Cataractogenesis is something to be concerned by radiologist and radiographer who work extensively in fluoroscopy. The increasing use of fluoroscopy or interventional fluoroscopy has to come with safety awareness on scattered radiation risk for staff performing the procedure. This study is looking into the radiation risk to the lens of the eyes for staff involved in fluoroscopy using the mobile C-arm fluoroscopy unit. The Toshiba SXT-1000A and Alderson Rando phantom were used in this study. Based on the results, it is found clearly that over couch (OC) procedure is riskier than under couch (UC) procedure. The cathode bound area is clearly riskier than anode bound area especially for UC procedure. More doses (at least +1,568 % of safest position) are received by the lens of the eyes for staff standing at the cathode bound area especially the position opposite to the x-ray tube.

Scattered radiation risk to the lens of the eyes for staff involved in using mobile C-arm fluoroscopy unit: Which position is riskiest?

International Nuclear Information System (INIS)

Salleh, H.; Matori, M. K.; Isa, M. J. M.; Samat, S. B.

2015-01-01

Cataractogenesis is something to be concerned by radiologist and radiographer who work extensively in fluoroscopy. The increasing use of fluoroscopy or interventional fluoroscopy has to come with safety awareness on scattered radiation risk for staff performing the procedure. This study is looking into the radiation risk to the lens of the eyes for staff involved in fluoroscopy using the mobile C-arm fluoroscopy unit. The Toshiba SXT-1000A and Alderson Rando phantom were used in this study. Based on the results, it is found clearly that over couch (OC) procedure is riskier than under couch (UC) procedure. The cathode bound area is clearly riskier than anode bound area especially for UC procedure. More doses (at least +1,568 % of safest position) are received by the lens of the eyes for staff standing at the cathode bound area especially the position opposite to the x-ray tube

The Hinge Segment of Human NADPH-Cytochrome P450 Reductase in Conformational Switching: The Critical Role of Ionic Strength

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Diana Campelo

2017-10-01

Full Text Available NADPH-cytochrome P450 reductase (CPR is a redox partner of microsomal cytochromes P450 and is a prototype of the diflavin reductase family. CPR contains 3 distinct functional domains: a FMN-binding domain (acceptor reduction, a linker (hinge, and a connecting/FAD domain (NADPH oxidation. It has been demonstrated that the mechanism of CPR exhibits an important step in which it switches from a compact, closed conformation (locked state to an ensemble of open conformations (unlocked state, the latter enabling electron transfer to redox partners. The conformational equilibrium between the locked and unlocked states has been shown to be highly dependent on ionic strength, reinforcing the hypothesis of the presence of critical salt interactions at the interface between the FMN and connecting FAD domains. Here we show that specific residues of the hinge segment are important in the control of the conformational equilibrium of CPR. We constructed six single mutants and two double mutants of the human CPR, targeting residues G240, S243, I245 and R246 of the hinge segment, with the aim of modifying the flexibility or the potential ionic interactions of the hinge segment. We measured the reduction of cytochrome c at various salt concentrations of these 8 mutants, either in the soluble or membrane-bound form of human CPR. All mutants were found capable of reducing cytochrome c yet with different efficiency and their maximal rates of cytochrome c reduction were shifted to lower salt concentration. In particular, residue R246 seems to play a key role in a salt bridge network present at the interface of the hinge and the connecting domain. Interestingly, the effects of mutations, although similar, demonstrated specific differences when present in the soluble or membrane-bound context. Our results demonstrate that the electrostatic and flexibility properties of the hinge segment are critical for electron transfer from CPR to its redox partners.

Sharing of secondary electrons by in-lens and out-lens detector in low-voltage scanning electron microscope equipped with immersion lens.

Science.gov (United States)

Kumagai, Kazuhiro; Sekiguchi, Takashi

2009-03-01

To understand secondary electron (SE) image formation with in-lens and out-lens detector in low-voltage scanning electron microscopy (LV-SEM), we have evaluated SE signals of an in-lens and an out-lens detector in LV-SEM. From the energy distribution spectra of SEs with various boosting voltages of the immersion lens system, we revealed that the electrostatic field of the immersion lens mainly collects electrons with energy lower than 40eV, acting as a low-pass filter. This effect is also observed as a contrast change in LV-SEM images taken by in-lens and out-lens detectors.

Sulforaphane-induced transcription of thioredoxin reductase in lens: possible significance against cataract formation

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Varma SD

2013-10-01

Full Text Available Shambhu D Varma, Krish Chandrasekaran, Svitlana Kovtun Department of Ophthalmology and Visual Sciences, University of Maryland, Baltimore, MD, USA Purpose: Sulforaphane is a phytochemically derived organic isothiocyanate 1-isothiocyanato-4-methylsulfinyl-butane present naturally in crucifers, including broccoli and cauliflower. Biochemically, it has been reported to induce the transcription of several antioxidant enzymes. Since such enzymes have been implicated in preventing cataract formation triggered by the intraocular generation of oxy-radical species, the purpose of this investigation was to examine whether it could induce the formation of antioxidant enzymes in the eye lens. Thioredoxin reductase (TrxR was used as the target of such induction. Methods: Mice lenses were cultured for an overnight period of 17 hours in medium 199 fortified with 10% fetal calf serum. Incubation was conducted in the absence and presence of sulforaphane (5 µM. Subsequently, the lenses were homogenized in phosphate-buffered saline (PBS, followed by centrifugation. TrxR activity was determined in the supernatant by measuring the nicotinamide adenine dinucleotide phosphate (reduced (NADPH-dependent reduction of 5,5´-dithiobis-2-nitrobenzoic acid (DTNB. Non-specific reduction of DTNB was corrected for by conducting parallel determinations in the presence of aurothiomalate. The reduction of DTNB was followed spectrophotometrically at 410 nm. Results: The activity of TrxR in the lenses incubated with sulforaphane was found to be elevated to 18 times of that observed in lenses incubated without sulforaphane. It was also noticeably higher in the lenses incubated without sulforaphane than in the un-incubated fresh lenses. However, this increase was much lower than that observed for lenses incubated with sulforaphane. Conclusion: Sulforaphane has been found to enhance TrxR activity in the mouse lens in culture. In view of the protective effect of the antioxidant enzymes

Consumption of NADPH for 2-HG Synthesis Increases Pentose Phosphate Pathway Flux and Sensitizes Cells to Oxidative Stress

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Susan J. Gelman

2018-01-01

Full Text Available Summary: Gain-of-function mutations in isocitrate dehydrogenase 1 (IDH1 occur in multiple types of human cancer. Here, we show that these mutations significantly disrupt NADPH homeostasis by consuming NADPH for 2-hydroxyglutarate (2-HG synthesis. Cells respond to 2-HG synthesis, but not exogenous administration of 2-HG, by increasing pentose phosphate pathway (PPP flux. We show that 2-HG production competes with reductive biosynthesis and the buffering of oxidative stress, processes that also require NADPH. IDH1 mutants have a decreased capacity to synthesize palmitate and an increased sensitivity to oxidative stress. Our results demonstrate that, even when NADPH is limiting, IDH1 mutants continue to synthesize 2-HG at the expense of other NADPH-requiring pathways that are essential for cell viability. Thus, rather than attempting to decrease 2-HG synthesis in the clinic, the consumption of NADPH by mutant IDH1 may be exploited as a metabolic weakness that sensitizes tumor cells to ionizing radiation, a commonly used anti-cancer therapy. : Using liquid chromatography/mass spectrometry (LC/MS and stable isotope tracing, Gelman et al. find that 2-HG production in cells with IDH1 mutations leads to increased pentose phosphate pathway activity to generate NADPH. Production of 2-HG competes with other NADPH-dependent pathways and sensitizes cells to redox stress. Keywords: 2-hydroxyglutarate, cancer metabolism, LC/MS, metabolomcis, pentose phosphate pathway, redox regulation

Purification, crystallization and preliminary X-ray analysis of l-sorbose reductase from Gluconobacter frateurii complexed with l-sorbose or NADPH

International Nuclear Information System (INIS)

Kubota, Keiko; Nagata, Koji; Miyazono, Ken-ichi; Toyama, Hirohide; Matsushita, Kazunobu; Tanokura, Masaru

2009-01-01

NADPH-dependent l-sorbose reductase from G. frateurii (SR) was expressed, purified and crystallized with l-sorbose or NADPH using the sitting-drop vapour-diffusion method. Crystals of the SR–l-sorbose complex and SR–NADPH complex diffracted X-rays to 2.38 and 1.90 Å resolution, respectively. NADPH-dependent l-sorbose reductase (SR) from Gluconobacter frateurii was expressed in Escherichia coli, purified and crystallized with l-sorbose or NADPH using the sitting-drop vapour-diffusion method at 293 K. Crystals of the SR–l-sorbose complex and the SR–NADPH complex were obtained using reservoir solutions containing PEG 2000 or PEG 400 as precipitants and diffracted X-rays to 2.38 and 1.90 Å resolution, respectively. The crystal of the SR–l-sorbose complex belonged to space group C222 1 , with unit-cell parameters a = 124.2, b = 124.1, c = 60.8 Å. The crystal of the SR–NADPH complex belonged to space group P2 1 , with unit-cell parameters a = 124.3, b = 61.0, c = 124.5 Å, β = 89.99°. The crystals contained two and eight molecules, respectively, in the asymmetric unit

Activation of NADPH oxidase mediates increased endoplasmic reticulum stress and left ventricular remodeling after myocardial infarction in rabbits.

Science.gov (United States)

Li, Bao; Tian, Jing; Sun, Yi; Xu, Tao-Rui; Chi, Rui-Fang; Zhang, Xiao-Li; Hu, Xin-Ling; Zhang, Yue-An; Qin, Fu-Zhong; Zhang, Wei-Fang

2015-05-01

Nicotinamide adenine dinucleotide 3-phosphate (NADPH) oxidase activity and endoplasmic reticulum (ER) stress are increased after myocardial infarction (MI). In this study, we proposed to test whether activation of the NADPH oxidase in the remote non-infarcted myocardium mediates ER stress and left ventricular (LV) remodeling after MI. Rabbits with MI or sham operation were randomly assigned to orally receive an NADPH oxidase inhibitor apocynin or placebo for 30 days. The agents were administered beginning at 1 week after surgery. MI rabbits exhibited decreases in LV fractional shortening, LV ejection fraction and the first derivative of the LV pressure rise, which were abolished by apocynin treatment. NADPH oxidase Nox2 protein and mRNA expressions were increased in the remote non-infarcted myocardium after MI. Immunolabeling further revealed that Nox2 was increased in cardiac myocytes in the remote myocardium. The apocynin treatment prevented increases in the Nox2 expression, NADPH oxidase activity, oxidative stress, myocyte apoptosis and GRP78, CHOP and cleaved caspase 12 protein expression in the remote myocardium. The apocynin treatment also attenuated increases in myocyte diameter and cardiac fibrosis. In cultured H9C2 cardiomyocytes exposed to angiotensin II, an important stimulus for post-MI remodeling, Nox2 knockdown with siRNA significantly inhibited angiotensin II-induced NADPH oxidase activation, reactive oxygen species and GRP78 and CHOP protein expression. We conclude that NADPH oxidase inhibition attenuates increased ER stress in the remote non-infarcted myocardium and LV remodeling late after MI in rabbits. These findings suggest that the activation of NADPH oxidase in the remote non-infarcted myocardium mediates increased ER stress, contributing to myocyte apoptosis and LV remodeling after MI. Copyright © 2015 Elsevier B.V. All rights reserved.

Oligo-carrageenan kappa increases NADPH, ascorbate and glutathione syntheses and TRR/TRX activities enhancing photosynthesis, basal metabolism, and growth in Eucalyptus trees.

Science.gov (United States)

González, Alberto; Moenne, Fabiola; Gómez, Melissa; Sáez, Claudio A; Contreras, Rodrigo A; Moenne, Alejandra

2014-01-01

In order to analyze the effect of OC kappa in redox status, photosynthesis, basal metabolism and growth in Eucalyptus globulus, trees were treated with water (control), with OC kappa at 1 mg mL(-1), or treated with inhibitors of NAD(P)H, ascorbate (ASC), and glutathione (GSH) syntheses and thioredoxin reductase (TRR) activity, CHS-828, lycorine, buthionine sulfoximine (BSO), and auranofin, respectively, and with OC kappa, and cultivated for 4 months. Treatment with OC kappa induced an increase in NADPH, ASC, and GSH syntheses, TRR and thioredoxin (TRX) activities, photosynthesis, growth and activities of basal metabolism enzymes such as rubisco, glutamine synthetase (GlnS), adenosine 5'-phosphosulfate reductase (APR), involved in C, N, and S assimilation, respectively, Krebs cycle and purine/pyrimidine synthesis enzymes. Treatment with inhibitors and OC kappa showed that increases in ASC, GSH, and TRR/TRX enhanced NADPH synthesis, increases in NADPH and TRR/TRX enhanced ASC and GSH syntheses, and only the increase in NADPH enhanced TRR/TRX activities. In addition, the increase in NADPH, ASC, GSH, and TRR/TRX enhanced photosynthesis and growth. Moreover, the increase in NADPH, ASC and TRR/TRX enhanced activities of rubisco, Krebs cycle, and purine/pyrimidine synthesis enzymes, the increase in GSH, NADPH, and TRR/TRX enhanced APR activity, and the increase in NADPH and TRR/TRX enhanced GlnS activity. Thus, OC kappa increases NADPH, ASC, and GSH syntheses leading to a more reducing redox status, the increase in NADPH, ASC, GSH syntheses, and TRR/TRX activities are cross-talking events leading to activation of photosynthesis, basal metabolism, and growth in Eucalyptus trees.

Oligo-carrageenan kappa increases NADPH, ascorbate and glutathione syntheses and TRR/TRX activities enhancing photosynthesis, basal metabolism, and growth in Eucalyptus trees

Directory of Open Access Journals (Sweden)

Alberto eGonzález

2014-10-01

Full Text Available In order to analyze the effect of OC kappa in redox status, photosynthesis, basal metabolism and growth in Eucalyptus globulus, trees were treated with water (control, with OC kappa at 1 mg mL-1, or treated with inhibitors of NAD(PH, ascorbate (ASC and glutathione (GSH syntheses and thioredoxin reductase (TRR activity, CHS-828, lycorine, buthionine sulfoximine (BSO and auranofin, respectively, and with OC kappa, and cultivated for 4 months. Treatment with OC kappa induced an increase in NADPH, ASC, and GSH syntheses, TRR and thioredoxin (TRX activities, photosynthesis, growth and activities of basal metabolism enzymes such as rubisco, glutamine synthetase (GlnS, adenosine 5´-phosphosulfate reductase (APR, involved in C, N and S assimilation, respectively, Krebs cycle and purine/pyrimidine synthesis enzymes. Treatment with inhibitors and OC kappa showed that increases in ASC, GSH and TRR/TRX enhanced NADPH synthesis, increases in NADPH and TRR/TRX enhanced ASC and GSH syntheses, and only the increase in NADPH enhanced TRR/TRX activities. In addition, the increase in NADPH, ASC, GSH and TRR/TRX enhanced photosynthesis and growth. Moreover, the increase in NADPH, ASC and TRR/TRX enhanced activities of rubisco, Krebs cycle and purine/pyrimidine synthesis enzymes, the increase in GSH, NADPH, and TRR/TRX enhanced APR activity, and the increase in NADPH and TRR/TRX enhanced GlnS activity. Thus, OC kappa increases NADPH, ASC and GSH syntheses leading to a more reducing redox status, the increase in NADPH, ASC, GSH syntheses and TRR/TRX activities are cross-talking events leading to activation of photosynthesis, basal metabolism and growth in Eucalyptus trees.

NAD(H) and NADP(H) Redox Couples and Cellular Energy Metabolism.

Science.gov (United States)

Xiao, Wusheng; Wang, Rui-Sheng; Handy, Diane E; Loscalzo, Joseph

2018-01-20

The nicotinamide adenine dinucleotide (NAD + )/reduced NAD + (NADH) and NADP + /reduced NADP + (NADPH) redox couples are essential for maintaining cellular redox homeostasis and for modulating numerous biological events, including cellular metabolism. Deficiency or imbalance of these two redox couples has been associated with many pathological disorders. Recent Advances: Newly identified biosynthetic enzymes and newly developed genetically encoded biosensors enable us to understand better how cells maintain compartmentalized NAD(H) and NADP(H) pools. The concept of redox stress (oxidative and reductive stress) reflected by changes in NAD(H)/NADP(H) has increasingly gained attention. The emerging roles of NAD + -consuming proteins in regulating cellular redox and metabolic homeostasis are active research topics. The biosynthesis and distribution of cellular NAD(H) and NADP(H) are highly compartmentalized. It is critical to understand how cells maintain the steady levels of these redox couple pools to ensure their normal functions and simultaneously avoid inducing redox stress. In addition, it is essential to understand how NAD(H)- and NADP(H)-utilizing enzymes interact with other signaling pathways, such as those regulated by hypoxia-inducible factor, to maintain cellular redox homeostasis and energy metabolism. Additional studies are needed to investigate the inter-relationships among compartmentalized NAD(H)/NADP(H) pools and how these two dinucleotide redox couples collaboratively regulate cellular redox states and cellular metabolism under normal and pathological conditions. Furthermore, recent studies suggest the utility of using pharmacological interventions or nutrient-based bioactive NAD + precursors as therapeutic interventions for metabolic diseases. Thus, a better understanding of the cellular functions of NAD(H) and NADP(H) may facilitate efforts to address a host of pathological disorders effectively. Antioxid. Redox Signal. 28, 251-272.

cAMP-dependent phosphorylation of bovine lens alpha-crystallin

International Nuclear Information System (INIS)

Spector, A.; Chiesa, R.; Sredy, J.; Garner, W.

1985-01-01

This communication reports that the A1 and B1 chains of bovine lens alpha-crystallin are phosphorylated. The conclusion is based on the following evidence: (i) When soluble preparations from lens cortex are incubated with [gamma- 32 P]ATP, a cAMP-dependent labeling of a high molecular weight protein is obtained. (ii) After NaDodSO 4 /PAGE, the label is found in two bands with Mr 22,000 and 20,000, corresponding to the B and A chains of alpha-crystallin, respectively. (iii) Isoelectric focusing indicates that the radioactivity is almost exclusively in bands with pI values of 5.58 and 6.70, corresponding to the A1 and B1 chains, respectively. (iv) Similar results are obtained in experiments of [ 32 P]orthophosphate incorporation in lens organ culture. (v) Analyses of the digested protein indicate the label is exclusively in phosphoserine. (vi) 31 P NMR analyses of native, proteolytically digested, and urea-treated alpha-crystallin gives a chemical shift of 4.6 ppm relative to 85% H 3 PO 4 at pH 7.4, suggesting that the phosphate is covalently bound to a serine in the protein. An abundance of approximately one phosphate per four or five monomer units was found. (vii) Similar results were obtained by chemical analyses of independently prepared alpha-crystallin samples. The results are consistent with the view that the A1 and B1 chains arise as result of the phosphorylation of directly synthesized A2 and B2 polypeptides. It is suggested that this metabolically controlled phosphorylation may be associated with the terminal differentiation of the lens epithelial cell and the intracellular organization of the lens fiber cell

Interferon gamma/NADPH oxidase defence system in immunity and cancer

Czech Academy of Sciences Publication Activity Database

Hodný, Zdeněk; Reiniš, Milan; Hubáčková, Soňa; Vašicová, Pavla; Bartek, Jiří

-, 01 Sep (2015) ISSN 2162-4011 Institutional support: RVO:68378050 ; RVO:61388971 Keywords : IFNγ * NADPH oxidase * immunity * cancer Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 6.266, year: 2014

Crosstalk between HDAC6 and Nox2-based NADPH oxidase mediates HIV-1 Tat-induced pro-inflammatory responses in astrocytes

Directory of Open Access Journals (Sweden)

Gi Soo Youn

2017-08-01

Full Text Available Histone deacetylase 6 (HDAC6 likely is important in inflammatory diseases. However, how HDAC6 exerts its effect on inflammatory processes remains unclear. HIV-1 transactivator of transcription (Tat activates NADPH oxidase resulting in generation of reactive oxygen species (ROS, leading to extensive neuro-inflammation in the central nervous system. We investigated the correlation of HDAC6 and NADPH oxidase in HIV-1 Tat-stimulated astrocytes. HDAC6 knockdown attenuated HIV-1 Tat-induced ROS generation and NADPH oxidase activation. HDAC6 knockdown suppressed HIV-1 Tat-induced expression of NADPH oxidase subunits, such as Nox2, p47phox, and p22phox. Specific inhibition of HDAC6 using tubastatin A suppressed HIV-1 Tat-induced ROS generation and activation of NADPH oxidase. N-acetyl cysteine, diphenyl iodonium, and apocynin suppressed HIV-1 Tat-induced expression of HDAC6 and the pro-inflammatory chemokines CCL2, CXCL8, and CXCL10. Nox2 knockdown attenuated HIV-1 Tat-induced HDAC6 expression and subsequent expression of chemokines. The collective results point to the potential crosstalk between HDAC6 and NADPH oxidase, which could be a combined therapeutic target for relief of HIV-1 Tat-mediated neuro-inflammation. Keywords: HIV-1 Tat, HDAC6, NADPH oxidase, ROS, Inflammation, Astrocytes

A novel strategy involved in [corrected] anti-oxidative defense: the conversion of NADH into NADPH by a metabolic network.

Directory of Open Access Journals (Sweden)

Ranji Singh

Full Text Available The reduced nicotinamide adenine dinucleotide phosphate (NADPH is pivotal to the cellular anti-oxidative defence strategies in most organisms. Although its production mediated by different enzyme systems has been relatively well-studied, metabolic networks dedicated to the biogenesis of NADPH have not been fully characterized. In this report, a metabolic pathway that promotes the conversion of reduced nicotinamide adenine dinucleotide (NADH, a pro-oxidant into NADPH has been uncovered in Pseudomonas fluorescens exposed to oxidative stress. Enzymes such as pyruvate carboxylase (PC, malic enzyme (ME, malate dehydrogenase (MDH, malate synthase (MS, and isocitrate lyase (ICL that are involved in disparate metabolic modules, converged to create a metabolic network aimed at the transformation of NADH into NADPH. The downregulation of phosphoenol carboxykinase (PEPCK and the upregulation of pyruvate kinase (PK ensured that this metabolic cycle fixed NADH into NADPH to combat the oxidative stress triggered by the menadione insult. This is the first demonstration of a metabolic network invoked to generate NADPH from NADH, a process that may be very effective in combating oxidative stress as the increase of an anti-oxidant is coupled to the decrease of a pro-oxidant.

Enhanced production of GDP-L-fucose by overexpression of NADPH regenerator in recombinant Escherichia coli.

Science.gov (United States)

Lee, Won-Heong; Chin, Young-Wook; Han, Nam Soo; Kim, Myoung-Dong; Seo, Jin-Ho

2011-08-01

Biosynthesis of guanosine 5'-diphosphate-L-fucose (GDP-L-fucose) requires NADPH as a reducing cofactor. In this study, endogenous NADPH regenerating enzymes such as glucose-6-phosphate dehydrogenase (G6PDH), isocitrate dehydrogenase (Icd), and NADP(+)-dependent malate dehydrogenase (MaeB) were overexpressed to increase GDP-L-fucose production in recombinant Escherichia coli. The effects of overexpression of each NADPH regenerating enzyme on GDP-L-fucose production were investigated in a series of batch and fed-batch fermentations. Batch fermentations showed that overexpression of G6PDH was the most effective for GDP-L-fucose production. However, GDP-L-fucose production was not enhanced by overexpression of G6PDH in the glucose-limited fed-batch fermentation. Hence, a glucose feeding strategy was optimized to enhance GDP-L-fucose production. Fed-batch fermentation with a pH-stat feeding mode for sufficient supply of glucose significantly enhanced GDP-L-fucose production compared with glucose-limited fed-batch fermentation. A maximum GDP-L-fucose concentration of 235.2 ± 3.3 mg l(-1), corresponding to a 21% enhancement in the GDP-L-fucose production compared with the control strain overexpressing GDP-L-fucose biosynthetic enzymes only, was achieved in the pH-stat fed-batch fermentation of the recombinant E. coli overexpressing G6PDH. It was concluded that sufficient glucose supply and efficient NADPH regeneration are crucial for NADPH-dependent GDP-L-fucose production in recombinant E. coli.

[Increasing reductant NADPH content via metabolic engineering of PHB synthesis pathway in Synechocystis sp. PCC 6803].

Science.gov (United States)

Xie, Juan; Zhou, Jie; Zhang, Haifeng; Li, Yin

2011-07-01

Cyanobacteria have become attractive hosts for renewable chemicals production. The low productivity, however, prevents it from industrial application. Reductant NAD(P)H availability is a chief hurdle for the production of reductive metabolites in microbes. To increase NADPH content in Synechocystis sp. PCC 6803, PHB synthase encoding gene phaC and phaE in Synechocystis was inactivated by replacing phaC&E genes with chloromycetin resistance cassette via homologous recombination. PCR analysis showed that mutant S.delta phaC&E with complete genome segregation was generated. The comparison between growth curves of S.wt and S.delta phaC&E indicated the knockout of phaC & phaE genes did not affect obviously the cell growth. Gas chromatography analysis showed that the accumulation of PHB in wild type was about 2.3% of the dry cell weight, whereas no PHB was detected in the mutant S.delta phaC&E. The data indicated that inactivation of PHB synthase gene phaC and phaE interrupted the synthesis of PHB. Further comparative study of wild type and mutant demonstrated that NADPH content in S.delta phaC&E was obviously increased. On the third day, the NADPH content in S.delta phaC&E was up to 1.85 fold higher than that in wild type. These results indicated that deleting PHB synthase gene phaC and phaE not only can block the synthesis of PHB, but also can save NADPH to contribute reductant sink in cyanobacteria. Hence, the engineered cyanobacterial strain S.delta phaC&E, in which carbon flux was redirected and NADPH was increased, will be a potential host strain for chemicals production in cyanobacteria.

Redox conditions and protein oxidation in plant mitochondria

DEFF Research Database (Denmark)

Møller, Ian Max; Kasimova, Marina R.; Krab, Klaas

2005-01-01

Redox conditions and protein oxidation in plant mitochondria NAD(P)H has a central position in respiratory metabolism. It is produced by a large number of enzymes, e.g. the Krebs cycle dehydrogenases, in the mitochondrial matrix and is oxidised by, amongst others, the respiratory chain. Most...... of this NAD(P)H appears to be bound to proteins, in fact free NAD(P)H – an important parameter in metabolic regulation - has never been observed in mitochondria. We have estimated free and bound NAD(P)H in isolated plant mitochondria under different metabolic conditions. The fluorescence spectra of free...... and bound NADH was determined and used to deconvolute fluorescence spectra of actively respiring mitochondria. Most of the mitochondrial NADH is bound in states 2 and 4. The amount of free NADH is lower but relatively constant even increasing a little in state 3 where it is about equal to bound NADH...

Post-lens tear turbidity and visual quality after scleral lens wear.

Science.gov (United States)

Carracedo, Gonzalo; Serramito-Blanco, Maria; Martin-Gil, Alba; Wang, Zicheng; Rodriguez-Pomar, Candela; Pintor, Jesús

2017-11-01

The aim was to evaluate the turbidity and thickness of the post-lens tear layer and its effect on visual quality in patients with keratoconus after the beginning of lens wear and before lens removal at the end of eight hours. Twenty-six patients with keratoconus (aged 36.95 ± 8.95 years) participated voluntarily in the study. The sample was divided into two groups: patients with intrastromal corneal ring (ICRS group) and patients without ICRS (KC group). Distance visual acuity (VA), contrast sensitivity, pachymetry, post-lens tear layer height and post-lens tear layer turbidity (percentage area occupied and number of particles per mm 2 ) were evaluated with optical coherence tomography before and after wearing a scleral lens. A significant increase of turbidity was found in all groups assessed (p turbidity parameters with distance VA but no correlation between turbidity and post-lens tear layer thickness at the beginning was found (p > 0.05). A strong correlation in all groups between the post-lens tear layer at the beginning and differences of tear layer thickness between two measures was also found (p turbidity. © 2017 Optometry Australia.

NADPH oxidase is involved in regulation of gene expression and ROS overproduction in soybean (Glycine max L. seedlings exposed to cadmium

Directory of Open Access Journals (Sweden)

Jagna Chmielowska-Bąk

2017-06-01

Full Text Available Cadmium-induced oxidative burst is partially mediated by NADPH oxidase. The aim of the present research was to evaluate the role of NADPH oxidase in soybeans’ response to short-term cadmium stress. The application of an NADPH oxidase inhibitor, diphenyleneiodonium chloride (DPI, affected expression of two Cd-inducible genes, encoding DOF1 and MYBZ2 transcription factors. This effect was observed after 3 h of treatment. Interestingly, Cd-dependent increases in NADPH oxidase activity occurred only after a period of time ranging from 6 and 24 h of stress. Stimulation of the enzyme correlated in time with a significant accumulation of reactive oxygen species (ROS. Further analysis revealed that pharmacological inhibition of NADPH oxidase activity during 24 h of Cd stress does not affect Cd uptake, seedling growth, or the level of lipid peroxidation. The role of NADPH oxidase in the response of soybean seedlings to short-term Cd exposure is discussed.

Disinfection capacity of PuriLens contact lens cleaning unit against Acanthamoeba.

Science.gov (United States)

Hwang, Thomas S; Hyon, Joon Young; Song, Jae Kyung; Reviglio, Victor E; Spahr, Harry T; O'Brien, Terrence P

2004-01-01

The PuriLens contact lens system is indicated for cleaning and disinfection of soft (hydrophilic) contact lenses by means of subsonic agitation to remove lens deposits and microorganisms, and ultraviolet irradiation of the storage solution for disinfection. The capacity of the PuriLens system to disinfect storage solutions contaminated with known concentrations of Staphylococcus aureus, Pseudomonas aeruginosa, and Acanthamoeba species was evaluated. An in vitro assessment of the antibacterial and antiparasitic efficacy of the PuriLens system was performed. Separated batches of the storage solution for the cleansing system were contaminated with stock strains of S. aureus and P. aeruginosa. A comparison of the microbiologic content was made between the solution before and after the cycle. The PuriLens system effectively eradicated S. aureus and P. aeruginosa organisms after a 15-minute cycle. However, viable cysts of acanthamoeba were recovered in the solution after the 15-minute cycle. The PuriLens system is highly efficient in protecting against contamination with common bacterial ocular pathogens. Acanthamoeba cysts, however, can survive in the solution or contact lens bath undergoing integrated subsonic debridement and indirect ultraviolet light disinfection. Use of chemical disinfecting solutions that contain agents such as chlorhexidine or other cationic antiseptics may be advisable in conjunction with use of the PuriLens device, especially in high-risk settings.

Gentamicin differentially alters cellular metabolism of cochlear hair cells as revealed by NAD(P)H fluorescence lifetime imaging

Science.gov (United States)

Zholudeva, Lyandysha V.; Ward, Kristina G.; Nichols, Michael G.; Smith, Heather Jensen

2015-05-01

Aminoglycoside antibiotics are implicated as culprits of hearing loss in more than 120,000 individuals annually. Research has shown that the sensory cells, but not supporting cells, of the cochlea are readily damaged and/or lost after use of such antibiotics. High-frequency outer hair cells (OHCs) show a greater sensitivity to antibiotics than high- and low-frequency inner hair cells (IHCs). We hypothesize that variations in mitochondrial metabolism account for differences in susceptibility. Fluorescence lifetime microscopy was used to quantify changes in NAD(P)H in sensory and supporting cells from explanted murine cochleae exposed to mitochondrial uncouplers, inhibitors, and an ototoxic antibiotic, gentamicin (GM). Changes in metabolic state resulted in a redistribution of NAD(P)H between subcellular fluorescence lifetime pools. Supporting cells had a significantly longer lifetime than sensory cells. Pretreatment with GM increased NAD(P)H intensity in high-frequency sensory cells, as well as the NAD(P)H lifetime within IHCs. GM specifically increased NAD(P)H concentration in high-frequency OHCs, but not in IHCs or pillar cells. Variations in NAD(P)H intensity in response to mitochondrial toxins and GM were greatest in high-frequency OHCs. These results demonstrate that GM rapidly alters mitochondrial metabolism, differentially modulates cell metabolism, and provides evidence that GM-induced changes in metabolism are significant and greatest in high-frequency OHCs.

The Effect of the Crystalline Lens on Central Vault After Implantable Collamer Lens Implantation.

Science.gov (United States)

Qi, Meng-Ying; Chen, Qian; Zeng, Qing-Yan

2017-08-01

To identify associations between crystalline lens-related factors and central vault after Implantable Collamer Lens (ICL) (Staar Surgical, Monrovia, CA) implantation. This retrospective clinical study included 320 eyes from 186 patients who underwent ICL implantation surgery. At 1 year after surgery, the central vault was measured using anterior segment optical coherence tomography. Preoperative anterior chamber depth, lens thickness, lens position (lens position = anterior chamber depth + 1/2 lens thickness), and vault were analyzed to investigate the effects of lens-related factors on postoperative vault. The mean vault was 513 ± 215 µm at 1 year after surgery. Vault was positively correlated with preoperative anterior chamber depth (r = 0.495, P lens position (r = 0.371, P lens thickness (r = -0.262, P lens position than eyes in the other two vault groups (which had vaults ≥ 250 µm) (P lens position less than 5.1 mm had greatly reduced vaults (P lens could have an important influence on postoperative vault. Eyes with a shallower anterior chamber and a forward lens position will have lower vaults. [J Refract Surg. 2017;33(8):519-523.]. Copyright 2017, SLACK Incorporated.

Purification and characterization of NADPH--cytochrome c reductase from the midgut of the southern armyworm (Spodoptera eridania).

Science.gov (United States)

Crankshaw, D L; Hetnarski, K; Wilkinson, C F

1979-09-01

1. NADPH-cytochrome c reductase was solubilized with bromelain and purified about 400-fold from sucrose/pyrophosphate-washed microsomal fractions from southern armyworm (Spodoptera eridania) larval midguts. 2. The enzyme has a mol.wt. of 70 035 +/- 1300 and contained 2 mol of flavin/mol of enzyme consisting of almost equimolar amounts of FMN and FAD. 3. Aerobic titration of the enzyme with NADPH caused the formation of a stable half-reduced state at 0.5 mol of NADPH/mol of flavin. 4. Kinetic analysis showed that the reduction of cytochrome c proceeded by a Bi Bi Ping Pong mechanism. 5. Apparent Km values for NADPH and cytochrome c and Ki values for NADP+ and 2'-AMP were considerably higher for the insect reductase than for the mammalian liver enzyme. 6. These are discussed in relation to possible differences in the active sites of the enzymes.

Measurement of Crystalline Lens Volume During Accommodation in a Lens Stretcher.

Science.gov (United States)

Marussich, Lauren; Manns, Fabrice; Nankivil, Derek; Maceo Heilman, Bianca; Yao, Yue; Arrieta-Quintero, Esdras; Ho, Arthur; Augusteyn, Robert; Parel, Jean-Marie

2015-07-01

To determine if the lens volume changes during accommodation. The study used data acquired on 36 cynomolgus monkey lenses that were stretched in a stepwise fashion to simulate disaccommodation. At each step, stretching force and dioptric power were measured and a cross-sectional image of the lens was acquired using an optical coherence tomography system. Images were corrected for refractive distortions and lens volume was calculated assuming rotational symmetry. The average change in lens volume was calculated and the relation between volume change and power change, and between volume change and stretching force, were quantified. Linear regressions of volume-power and volume-force plots were calculated. The mean (± SD) volume in the unstretched (accommodated) state was 97 ± 8 mm3. On average, there was a small but statistically significant (P = 0.002) increase in measured lens volume with stretching. The mean change in lens volume was +0.8 ± 1.3 mm3. The mean volume-power and volume-load slopes were -0.018 ± 0.058 mm3/D and +0.16 ± 0.40 mm3/g. Lens volume remains effectively constant during accommodation, with changes that are less than 1% on average. This result supports a hypothesis that the change in lens shape with accommodation is accompanied by a redistribution of tissue within the capsular bag without significant compression of the lens contents or fluid exchange through the capsule.

Increasing anaerobic acetate consumption and ethanol yields in Saccharomyces cerevisiae with NADPH-specific alcohol dehydrogenase.

Science.gov (United States)

Henningsen, Brooks M; Hon, Shuen; Covalla, Sean F; Sonu, Carolina; Argyros, D Aaron; Barrett, Trisha F; Wiswall, Erin; Froehlich, Allan C; Zelle, Rintze M

2015-12-01

Saccharomyces cerevisiae has recently been engineered to use acetate, a primary inhibitor in lignocellulosic hydrolysates, as a cosubstrate during anaerobic ethanolic fermentation. However, the original metabolic pathway devised to convert acetate to ethanol uses NADH-specific acetylating acetaldehyde dehydrogenase and alcohol dehydrogenase and quickly becomes constrained by limited NADH availability, even when glycerol formation is abolished. We present alcohol dehydrogenase as a novel target for anaerobic redox engineering of S. cerevisiae. Introduction of an NADPH-specific alcohol dehydrogenase (NADPH-ADH) not only reduces the NADH demand of the acetate-to-ethanol pathway but also allows the cell to effectively exchange NADPH for NADH during sugar fermentation. Unlike NADH, NADPH can be freely generated under anoxic conditions, via the oxidative pentose phosphate pathway. We show that an industrial bioethanol strain engineered with the original pathway (expressing acetylating acetaldehyde dehydrogenase from Bifidobacterium adolescentis and with deletions of glycerol-3-phosphate dehydrogenase genes GPD1 and GPD2) consumed 1.9 g liter(-1) acetate during fermentation of 114 g liter(-1) glucose. Combined with a decrease in glycerol production from 4.0 to 0.1 g liter(-1), this increased the ethanol yield by 4% over that for the wild type. We provide evidence that acetate consumption in this strain is indeed limited by NADH availability. By introducing an NADPH-ADH from Entamoeba histolytica and with overexpression of ACS2 and ZWF1, we increased acetate consumption to 5.3 g liter(-1) and raised the ethanol yield to 7% above the wild-type level. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Effect of a heme oxygenase-1 inducer on NADPH oxidase ...

African Journals Online (AJOL)

Effect of a heme oxygenase-1 inducer on NADPH oxidase expression in ... and immunohistochemistry of hepatic NOX1 and NOX4 were investigated in week 4. ... (HO-1 inhibitor) administration caused upregulation of NOX gene expression ...

NADPH oxidase: an enzyme for multicellularity?

Science.gov (United States)

Lalucque, Hervé; Silar, Philippe

2003-01-01

Multicellularity has evolved several times during the evolution of eukaryotes. One evolutionary pressure that permits multicellularity relates to the division of work, where one group of cells functions as nutrient providers and the other in specialized roles such as defence or reproduction. This requires signalling systems to ensure harmonious development of multicellular structures. Here, we show that NADPH oxidases are specifically present in organisms that differentiate multicellular structures during their life cycle and are absent from unicellular life forms. The biochemical properties of these enzymes make them ideal candidates for a role in intercellular signalling.

AutoLens: Automated Modeling of a Strong Lens's Light, Mass and Source

Science.gov (United States)

Nightingale, J. W.; Dye, S.; Massey, Richard J.

2018-05-01

This work presents AutoLens, the first entirely automated modeling suite for the analysis of galaxy-scale strong gravitational lenses. AutoLens simultaneously models the lens galaxy's light and mass whilst reconstructing the extended source galaxy on an adaptive pixel-grid. The method's approach to source-plane discretization is amorphous, adapting its clustering and regularization to the intrinsic properties of the lensed source. The lens's light is fitted using a superposition of Sersic functions, allowing AutoLens to cleanly deblend its light from the source. Single component mass models representing the lens's total mass density profile are demonstrated, which in conjunction with light modeling can detect central images using a centrally cored profile. Decomposed mass modeling is also shown, which can fully decouple a lens's light and dark matter and determine whether the two component are geometrically aligned. The complexity of the light and mass models are automatically chosen via Bayesian model comparison. These steps form AutoLens's automated analysis pipeline, such that all results in this work are generated without any user-intervention. This is rigorously tested on a large suite of simulated images, assessing its performance on a broad range of lens profiles, source morphologies and lensing geometries. The method's performance is excellent, with accurate light, mass and source profiles inferred for data sets representative of both existing Hubble imaging and future Euclid wide-field observations.

Optical integration of Pancharatnam-Berry phase lens and dynamical phase lens

International Nuclear Information System (INIS)

Ke, Yougang; Liu, Yachao; Zhou, Junxiao; Liu, Yuanyuan; Luo, Hailu; Wen, Shuangchun

2016-01-01

In the optical system, most elements such as lens, prism, and optical fiber are made of silica glass. Therefore, integrating Pancharatnam-Berry phase elements into silica glass has potential applications in the optical system. In this paper, we take a lens, for example, which integrates a Pancharatnam-Berry phase lens into a conventional plano-convex lens. The spin states and positions of focal points can be modulated by controlling the polarization states of the incident beam. The proposed lens has a high transmission efficiency, and thereby acts as a simple and powerful tool to manipulate spin photons. Furthermore, the method can be conveniently extended to the optical fiber and laser cavity, and may provide a route to the design of the spin-photonic devices.

Converging or Diverging Lens?

Science.gov (United States)

Branca, Mario

2013-01-01

Why does a lens magnify? Why does it shrink objects? Why does this happen? The activities that we propose here are useful in helping us to understand how lenses work, and they show that the same lens can have different magnification capabilities. A converging lens can also act as a diverging lens. (Contains 4 figures.)

Pre-steady-state kinetic studies of redox reactions catalysed by Bacillus subtilis ferredoxin-NADP(+) oxidoreductase with NADP(+)/NADPH and ferredoxin.

Science.gov (United States)

Seo, Daisuke; Soeta, Takahiro; Sakurai, Hidehiro; Sétif, Pierre; Sakurai, Takeshi

2016-06-01

Ferredoxin-NADP(+) oxidoreductase ([EC1.18.1.2], FNR) from Bacillus subtilis (BsFNR) is a homodimeric flavoprotein sharing structural homology with bacterial NADPH-thioredoxin reductase. Pre-steady-state kinetics of the reactions of BsFNR with NADP(+), NADPH, NADPD (deuterated form) and B. subtilis ferredoxin (BsFd) using stopped-flow spectrophotometry were studied. Mixing BsFNR with NADP(+) and NADPH yielded two types of charge-transfer (CT) complexes, oxidized FNR (FNR(ox))-NADPH and reduced FNR (FNR(red))-NADP(+), both having CT absorption bands centered at approximately 600n m. After mixing BsFNR(ox) with about a 10-fold molar excess of NADPH (forward reaction), BsFNR was almost completely reduced at equilibrium. When BsFNR(red) was mixed with NADP(+), the amount of BsFNR(ox) increased with increasing NADP(+) concentration, but BsFNR(red) remained as the major species at equilibrium even with about 50-fold molar excess NADP(+). In both directions, the hydride-transfer was the rate-determining step, where the forward direction rate constant (~500 s(-1)) was much higher than the reverse one (reaction. The characteristics of the BsFNR reactions with NADP(+)/NADPH were compared with those of other types of FNRs. Copyright © 2016 Elsevier B.V. All rights reserved.

Placement of a crystalline lens and intraocular lens: Retinal image quality.

Science.gov (United States)

Siedlecki, Damian; Nowak, Jerzy; Zajac, Marek

2006-01-01

The influence of changes of both crystalline lens and intraocular lens (IOL) misalignment on the retinal image quality was investigated. The optical model of the eye used in investigations was the Liou-Brennan model, which is commonly considered as one of the most anatomically accurate. The original crystalline lens from this model was replaced with an IOL, made of rigid polymethylmethacrylate, in a way that recommend obligatory procedures. The modifications that were made both for crystalline lens and IOL were the longitudinal, the transversal, and the angular displacement.

Refractive neutron lens

International Nuclear Information System (INIS)

Petrov, P.V.; Kolchevsky, N.N.

2013-01-01

Model of the refractive neutron lens is proposed. System of N lenses acts as one thin lens with a complex refraction index n*. The maximum number N max of individual lenses for 'thick' neutron lens is calculated. Refractive neutron lens properties (resolution, focal depth) as function of resolution factor F 0 =ρbc/μ and depth of field factor dF 0 =λF 0 =λρbc/μ are calculated. It is shown that micro resolution of the refractive neutron optics is far from the wavelength in size and its open possibilities for progress in refractive neutron optics. (authors)

Exchange of tears under a contact lens is driven by distortions of the contact lens.

Science.gov (United States)

Maki, Kara L; Ross, David S

2014-12-01

We studied the flow of the post-lens tear film under a soft contact lens to understand how the design parameters of contact lenses can affect ocular health. When a soft contact lens is inserted, the blinking eyelid causes the lens to stretch in order to conform to the shape of the eye. The deformed contact lens acts to assume its un-deformed shape and thus generates a suction pressure in the post-lens tear film. In consequence, the post-lens tear fluid moves; it responds to the suction pressure. The suction pressure may draw in fresh fluid from the edge of the lens, or it may eject fluid there, as the lens reassumes its un-deformed shape. In this article, we develop a mathematical model of the flow of the post-lens tear fluid in response to the mechanical suction pressure of a deformed contact lens. We predict the amount of exchange of fluid exchange under a contact lens and we explore the influence of the eye's shape on the rate of exchange of fluid. © The Author 2014. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Structure of conjugated polyketone reductase from Candida parapsilosis IFO 0708 reveals conformational changes for substrate recognition upon NADPH binding.

Science.gov (United States)

Qin, Hui-Min; Yamamura, Akihiro; Miyakawa, Takuya; Kataoka, Michihiko; Nagai, Takahiro; Kitamura, Nahoko; Urano, Nobuyuki; Maruoka, Shintaro; Ohtsuka, Jun; Nagata, Koji; Shimizu, Sakayu; Tanokura, Masaru

2014-01-01

Conjugated polyketone reductase C2 (CPR-C2) from Candida parapsilosis IFO 0708, identified as a nicotinamide adenine dinucleotide phosphate (NADPH)-dependent ketopantoyl lactone reductase, belongs to the aldo-keto reductase superfamily. This enzyme reduces ketopantoyl lactone to D-pantoyl lactone in a strictly stereospecific manner. To elucidate the structural basis of the substrate specificity, we determined the crystal structures of the apo CPR-C2 and CPR-C2/NADPH complex at 1.70 and 1.80 Å resolutions, respectively. CPR-C2 adopted a triose-phosphate isomerase barrel fold at the core of the structure. Binding with the cofactor NADPH induced conformational changes in which Thr27 and Lys28 moved 15 and 5.0 Å, respectively, in the close vicinity of the adenosine 2'-phosphate group of NADPH to form hydrogen bonds. Based on the comparison of the CPR-C2/NADPH structure with 3-α-hydroxysteroid dehydrogenase and mutation analyses, we constructed substrate binding models with ketopantoyl lactone, which provided insight into the substrate specificity by the cofactor-induced structure. The results will be useful for the rational design of CPR-C2 mutants targeted for use in the industrial manufacture of ketopantoyl lactone.

Peripheral Defocus of the Monkey Crystalline Lens With Accommodation in a Lens Stretcher

Science.gov (United States)

Maceo Heilman, Bianca; Manns, Fabrice; Ruggeri, Marco; Ho, Arthur; Gonzalez, Alex; Rowaan, Cor; Bernal, Andres; Arrieta, Esdras; Parel, Jean-Marie

2018-01-01

Purpose To characterize the peripheral defocus of the monkey crystalline lens and its changes with accommodation. Methods Experiments were performed on 15 lenses from 11 cynomolgus monkey eyes (age: 3.8–12.4 years, postmortem time: 33.5 ± 15.3 hours). The tissue was mounted in a motorized lens stretcher to allow for measurements of the lens in the accommodated (unstretched) and unaccommodated (stretched) states. A custom-built combined laser ray tracing and optical coherence tomography system was used to measure the paraxial on-axis and off-axis lens power for delivery angles ranging from −20° to +20° (in air). For each delivery angle, peripheral defocus was quantified as the difference between paraxial off-axis and on-axis power. The peripheral defocus of the lens was compared in the unstretched and stretched states. Results On average, the paraxial on-axis lens power was 52.0 ± 3.4 D in the unstretched state and 32.5 ± 5.1 D in the stretched state. In both states, the lens power increased with increasing delivery angle. From 0° to +20°, the relative peripheral lens power increased by 10.7 ± 1.4 D in the unstretched state and 7.5 ± 1.6 D in the stretched state. The change in field curvature with accommodation was statistically significant (P lens has greater curvature or relative peripheral power. Conclusions The cynomolgus monkey lens has significant accommodation-dependent curvature of field, which suggests that the lens asserts a significant contribution to the peripheral optical performance of the eye that also varies with the state of accommodation.

Vitamin E--a selective inhibitor of the NADPH oxidoreductase enzyme system in human granulocytes

International Nuclear Information System (INIS)

Butterick, C.J.; Baehner, R.L.; Boxer, L.A.; Jersild, R.A. Jr.

1983-01-01

The cellular sites of H 2 O 2 formation in phagocytizing granulocytes have been identified with cerium chloride. A precipitate was visible in phagosomes and on plasma membranes from intact normal cells in the presence of either 0.71 mM NADH or NADPH. X-ray microanalysis permitted identification of cerium deposition within the phagosomes even in the absence of reduced pyridine nucleotides. Catalase ablated the formation of the reaction product. Intact granulocytes obtained from subjects receiving 1600 units of vitamin E daily for 2 weeks exhibited reaction product in the presence of NADH but not NADPH. Intact cells from subjects treated with vitamin E demonstrated diminished numbers of phagocytic vesicles containing reaction product. During phagocytosis the granulocytes treated with vitamin E consumed oxygen but exhibited significantly reduced rates of hydrogen-peroxide-dependent glucose-1- 14 C oxidation to 14 CO 2 . Isolated phagocytic vesicles obtained from granulocytes after ingestion of opsonized lipopolysaccharide-paraffin oil droplets contained reaction product when exposed to 0.71 mM NADPH. No reaction product was evident at 0.71 mM NADH but was evident at 2.0 mM NADH. Isolated phagocytic vesicles from the granulocytes of subjects receiving vitamin E exhibited reaction product only in the presence of NADH. These observations suggest that vitamin E interferes with the electron transport chain apparently required for the oxidation of NADPH to form H 2 O 2 in the phagocytizing granulocyte

The microglial NADPH oxidase complex as a source of oxidative stress in Alzheimer's disease

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Landreth Gary E

2006-11-01

Full Text Available Abstract Alzheimer's disease is the most common cause of dementia in the elderly, and manifests as progressive cognitive decline and profound neuronal loss. The principal neuropathological hallmarks of Alzheimer's disease are the senile plaques and the neurofibrillary tangles. The senile plaques are surrounded by activated microglia, which are largely responsible for the proinflammatory environment within the diseased brain. Microglia are the resident innate immune cells in the brain. In response to contact with fibrillar beta-amyloid, microglia secrete a diverse array of proinflammatory molecules. Evidence suggests that oxidative stress emanating from activated microglia contribute to the neuronal loss characteristic of this disease. The source of fibrillar beta-amyloid induced reactive oxygen species is primarily the microglial nicotinamide adenine dinucleotide phosphate (NADPH oxidase. The NADPH oxidase is a multicomponent enzyme complex that, upon activation, produces the highly reactive free radical superoxide. The cascade of intracellular signaling events leading to NADPH oxidase assembly and the subsequent release of superoxide in fibrillar beta-amyloid stimulated microglia has recently been elucidated. The induction of reactive oxygen species, as well as nitric oxide, from activated microglia can enhance the production of more potent free radicals such as peroxynitrite. The formation of peroxynitrite causes protein oxidation, lipid peroxidation and DNA damage, which ultimately lead to neuronal cell death. The elimination of beta-amyloid-induced oxidative damage through the inhibition of the NADPH oxidase represents an attractive therapeutic target for the treatment of Alzheimer's disease.

NADPH oxidase-mediated generation of reactive oxygen species: A new mechanism for X-ray-induced HeLa cell death

International Nuclear Information System (INIS)

Liu Qing; He Xiaoqing; Liu Yongsheng; Du Bingbing; Wang Xiaoyan; Zhang Weisheng; Jia Pengfei; Dong Jingmei; Ma Jianxiu; Wang Xiaohu; Li Sha; Zhang Hong

2008-01-01

Oxidative damage is an important mechanism in X-ray-induced cell death. Radiolysis of water molecules is a source of reactive oxygen species (ROS) that contribute to X-ray-induced cell death. In this study, we showed by ROS detection and a cell survival assay that NADPH oxidase has a very important role in X-ray-induced cell death. Under X-ray irradiation, the upregulation of the expression of NADPH oxidase membrane subunit gp91 phox was dose-dependent. Meanwhile, the cytoplasmic subunit p47 phox was translocated to the cell membrane and localized with p22 phox and gp91 phox to form reactive NADPH oxidase. Our data suggest, for the first time, that NADPH oxidase-mediated generation of ROS is an important contributor to X-ray-induced cell death. This suggests a new target for combined gene transfer and radiotherapy.

Compliance among soft contact lens wearers.

Science.gov (United States)

Kuzman, Tomislav; Kutija, Marija Barisić; Masnec, Sanja; Jandroković, Sonja; Mrazovac, Danijela; Jurisić, Darija; Skegro, Ivan; Kalauz, Miro; Kordić, Rajko

2014-12-01

Contact lens compliance is proven to be crucial for preventing lens wear-related complications because of the interdependence of the steps in lens care regime and their influence on lens system microbial contamination. Awareness of the patients' lens handling compliance as well as correct recognition of non-compliant behaviours is the basis for creating more targeted strategies for patient education. The aim of this study was to investigate compliance among soft contact lens (SCL) wearers in different aspects of lens care handling and wearing habits. In our research 50 asymptomatic lens wearers filled out a questionnaire containing demographic data, lens type, hygiene and wearing habits, lenses and lens care system replacement schedule and self-evaluation of contact lens handling hygiene. We established criteria of compliance according to available manufacturer's recommendations, prior literature and our clinical experience. Only 2 (4%) of patients were fully compliant SCL wearers. The most common non-compliant behaviours were insufficient lens solution soaking time (62%), followed by failure to daily exchange lens case solution and showering while wearing lenses. 44% of patients reported storing lenses in saline solution. Mean lens storage case replacement was 3.6 months, with up to 78% patients replacing lens case at least once in 3 months. Average grade in self evaluating level of compliance was very good (4 +/- 0.78) (from 1-poor level of hygiene to 5-great level of hygiene). Lens wearers who reported excessive daily lens wear and more than 10 years of lens wearing experience were also found to be less compliant with other lens system care procedures. (t = -2.99, df=47, p rate, self grading was relatively high. Therefore, these results indicate the need for patient education and encouragement of better lens wearing habits and all of the lens maintenance steps at each patient visit.

Comparison of clear lens extraction and collamer lens implantation in high myopia

Directory of Open Access Journals (Sweden)

Ahmed M Emarah

2010-05-01

Full Text Available Ahmed M Emarah, Mostafa A El-Helw, Hazem M YassinCairo University, Cairo, EgyptAim: To compare the outcomes of clear lens extraction and collamer lens implantation in high myopia.Patients and methods: Myopic patients younger than 40 years old with more than 12 diopters of myopia or who were not fit for laser-assisted in situ keratomileusis were included. Group 1 comprised patients undergoing clear lens extraction and Group 2 patients received the Visian implantable collamer lens. Outcome and complications were evaluated.Results: Postoperative best corrected visual acuity was -0.61 ± 0.18 in Group 1 and 0.79 ± 0.16 in Group 2. In Group 1, 71.4% achieved a postoperative uncorrected visual acuity better than the preoperative best corrected visual acuity, while only 51.8% patients achieved this in Group 2. Intraocular pressure decreased by 12.55% in Group 1, and increased by 15.11% in Group 2. Corneal endothelial cell density decreased by 4.47% in Group 1 and decreased by 5.67% in Group 2. Posterior capsule opacification occurred in Group 1. In Group 2, lens opacification occurred in 11.11%, significant pigment dispersion in 3.7%, and pupillary block glaucoma in 3.7%.Conclusion: Clear lens extraction presents less of a financial load up front, and less likelihood of the need for a secondary intervention in the future. Clear lens extraction is a more viable solution in developing countries with limited financial resources.Keywords: clear lens extraction, implantable collamer lens, myopia

Changes in lens stiffness due to capsular opacification in accommodative lens refilling

NARCIS (Netherlands)

Nibourg, Lisanne M.; Sharma, Prashant K.; van Kooten, Theo G.; Koopmans, Steven A.

Accommodation may be restored to presbyopic lenses by refilling the lens capsular bag with a soft polymer. After this accommodative lens refilling prevention of capsular opacification is a requirement, since capsular opacification leads to a decreased clarity of the refilled lens. It has been

(--Epigallocatechin gallate attenuates NADPH-d/nNOS expression in motor neurons of rats following peripheral nerve injury

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Tseng Chi-Yu

2011-06-01

Full Text Available Abstract Background Oxidative stress and large amounts of nitric oxide (NO have been implicated in the pathophysiology of neuronal injury and neurodegenerative disease. Recent studies have shown that (--epigallocatechin gallate (EGCG, one of the green tea polyphenols, has potent antioxidant effects against free radical-mediated lipid peroxidation in ischemia-induced neuronal damage. The purpose of this study was to examine whether EGCG would attenuate neuronal expression of NADPH-d/nNOS in the motor neurons of the lower brainstem following peripheral nerve crush. Thus, young adult rats were treated with EGCG (10, 25, or 50 mg/kg, i.p. 30 min prior to crushing their hypoglossal and vagus nerves for 30 seconds (left side, at the cervical level. The treatment (pre-crush doses of EGCG was continued from day 1 to day 6, and the animals were sacrificed on days 3, 7, 14 and 28. Nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d histochemistry and neuronal nitric oxide synthase (nNOS immunohistochemistry were used to assess neuronal NADPH-d/nNOS expression in the hypoglossal nucleus and dorsal motor nucleus of the vagus. Results In rats treated with high dosages of EGCG (25 or 50 mg/kg, NADPH-d/nNOS reactivity and cell death of the motor neurons were significantly decreased. Conclusions The present evidence indicated that EGCG can reduce NADPH-d/nNOS reactivity and thus may enhance motor neuron survival time following peripheral nerve injury.

Histochemical characterization, distribution and morphometric analysis of NADPH diaphorase neurons in the spinal cord of the agouti

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Marco Aurelio M Freire

2008-05-01

Full Text Available We evaluated the neuropil distribution of the enzymes NADPH diaphorase (NADPH-d and cytochrome oxidase (CO in the spinal cord of the agouti, a medium-sized diurnal rodent, together with the distribution pattern and morphometrical characteristics of NADPH-d reactive neurons across different spinal segments. Neuropil labeling pattern was remarkably similar for both enzymes in coronal sections: reactivity was higher in regions involved with pain processing. We found two distinct types of NADPH-d reactive neurons in the agouti’s spinal cord: type I neurons had large, heavily stained cell bodies while type II neurons displayed relatively small and poorly stained somata. We concentrated our analysis on type I neurons. These were found mainly in the dorsal horn and around the central canal of every spinal segment, with a few scattered neurons located in the ventral horn of both cervical and lumbar regions. Overall, type I neurons were more numerous in the cervical region. Type I neurons were also found in the white matter, particularly in the ventral funiculum. Morphometrical analysis revealed that type I neurons located in the cervical region have dendritic trees that are more complex than those located in both lumbar and thoracic regions. In addition, NADPH-d cells located in the ventral horn had a larger cell body, especially in lumbar segments. The resulting pattern of cell body and neuropil distribution is in accordance with proposed schemes of segregation of function in the mammalian spinal cord.

Mitochondrial NAD(PH in vivo: identifying natural indicators of oxidative phosphorylation in the 31P magnetic resonance spectrum.

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Kevin eConley

2016-03-01

Full Text Available Natural indicators provide intrinsic probes of metabolism, biogenesis and oxidative protection. Nicotinamide adenine dinucleotide metabolites (NAD(P are one class of indicators that have roles as co-factors in oxidative phosphorylation, glycolysis and anti-oxidant protection, as well as signaling in the mitochondrial biogenesis pathway. These many roles are made possible by the distinct redox states (NAD(P+ and NAD(PH, which are compartmentalized between cell and mitochondria. Here we provide evidence for detection of NAD(P+ and NAD(PH in separate mitochondrial and cell pools in vivo in human tissue by phosphorus magnetic resonance spectroscopy (31P MRS. These NAD(P pools are identified by chemical standards (NAD+, NADP+ and NADH and by physiological tests. A unique resonance reflecting mitochondrial NAD(PH is revealed by the changes elicited by elevation of mitochondrial oxidation. The decline of NAD(PH with oxidation is matched by a stoichiometric rise in the NAD(P+ peak. This unique resonance also provides a measure of the improvement in mitochondrial oxidation that parallels the greater phosphorylation found after exercise training in these elderly subjects. The implication is that the dynamics of the mitochondrial NAD(PH peak provides an intrinsic probe of the reversal of mitochondrial dysfunction in elderly muscle. Thus non-invasive detection of NAD(P+ and NAD(PH in cell vs. mitochondria yield natural indicators of redox compartmentalization and sensitive intrinsic probes of the improvement of mitochondrial function with an intervention in human tissues in vivo. These natural indicators hold the promise of providing mechanistic insight into metabolism and mitochondrial function in vivo in a range of tissues in health, disease and with treatment.

TMEM16A Contributes to Endothelial Dysfunction by Facilitating Nox2 NADPH Oxidase-Derived Reactive Oxygen Species Generation in Hypertension.

Science.gov (United States)

Ma, Ming-Ming; Gao, Min; Guo, Kai-Min; Wang, Mi; Li, Xiang-Yu; Zeng, Xue-Lin; Sun, Lu; Lv, Xiao-Fei; Du, Yan-Hua; Wang, Guan-Lei; Zhou, Jia-Guo; Guan, Yong-Yuan

2017-05-01

Ca 2+ -activated Cl - channels play a crucial role in various physiological processes. However, the role of TMEM16A in vascular endothelial dysfunction during hypertension is unclear. In this study, we investigated the specific involvement of TMEM16A in regulating endothelial function and blood pressure and the underlying mechanism. Reverse transcription-polymerase chain reaction, Western blotting, coimmunoprecipitation, confocal imaging, patch-clamp recordings, and TMEM16A endothelial-specific transgenic and knockout mice were used. We found that TMEM16A was expressed abundantly and functioned as a Ca 2+ -activated Cl - channel in endothelial cells. Angiotensin II induced endothelial dysfunction with an increase in TMEM16A expression. The knockout of endothelial-specific TMEM16A significantly lowered the blood pressure and ameliorated endothelial dysfunction in angiotensin II-induced hypertension, whereas the overexpression of endothelial-specific TMEM16A resulted in the opposite effects. These results were related to the increased reactive oxygen species production, Nox2-containing NADPH oxidase activation, and Nox2 and p22phox protein expression that were facilitated by TMEM16A on angiotensin II-induced hypertensive challenge. Moreover, TMEM16A directly bound with Nox2 and reduced the degradation of Nox2 through the proteasome-dependent degradation pathway. Therefore, TMEM16A is a positive regulator of endothelial reactive oxygen species generation via Nox2-containing NADPH oxidase, which induces endothelial dysfunction and hypertension. Modification of TMEM16A may be a novel therapeutic strategy for endothelial dysfunction-associated diseases. © 2017 American Heart Association, Inc.

TU-E-201-03: Eye Lens Dosimetry in Radiotherapy Using Contact Lens-Shaped Applicator

Energy Technology Data Exchange (ETDEWEB)

Park, J. [Seoul National University Hospital (Korea, Republic of)

2015-06-15

Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

TU-E-201-03: Eye Lens Dosimetry in Radiotherapy Using Contact Lens-Shaped Applicator

International Nuclear Information System (INIS)

Park, J.

2015-01-01

Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

Contact Lens-Related Eye Infections

Science.gov (United States)

... Español Eye Health / Eye Health A-Z Contact Lens-Related Eye Infections Sections Contact Lens-Related Eye ... Six Steps to Avoid Contact Lens Infections Contact Lens-Related Eye Infections Leer en Español: Infecciones relacionadas ...

Intermittent hypoxia-induced cognitive deficits are mediated by NADPH oxidase activity in a murine model of sleep apnea.

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Deepti Nair

Full Text Available In rodents, exposure to intermittent hypoxia (IH, a hallmark of obstructive sleep apnea (OSA, is associated with neurobehavioral impairments, increased apoptosis in the hippocampus and cortex, as well as increased oxidant stress and inflammation. Excessive NADPH oxidase activity may play a role in IH-induced CNS dysfunction.The effect of IH during light period on two forms of spatial learning in the water maze and well as markers of oxidative stress was assessed in mice lacking NADPH oxidase activity (gp91phox(_/Y and wild-type littermates. On a standard place training task, gp91phox(_/Y displayed normal learning, and were protected from the spatial learning deficits observed in wild-type littermates exposed to IH. Moreover, anxiety levels were increased in wild-type mice exposed to IH as compared to room air (RA controls, while no changes emerged in gp91phox(_/Y mice. Additionally, wild-type mice, but not gp91phox(_/Y mice had significantly elevated levels of NADPH oxidase expression and activity, as well as MDA and 8-OHDG in cortical and hippocampal lysates following IH exposures.The oxidative stress responses and neurobehavioral impairments induced by IH during sleep are mediated, at least in part, by excessive NADPH oxidase activity, and thus pharmacological agents targeting NADPH oxidase may provide a therapeutic strategy in sleep-disordered breathing.

Ozone affects pollen viability and NAD(P)H oxidase release from Ambrosia artemisiifolia pollen.

Science.gov (United States)

Pasqualini, Stefania; Tedeschini, Emma; Frenguelli, Giuseppe; Wopfner, Nicole; Ferreira, Fatima; D'Amato, Gennaro; Ederli, Luisa

2011-10-01

Air pollution is frequently proposed as a cause of the increased incidence of allergy in industrialised countries. We investigated the impact of ozone (O(3)) on reactive oxygen species (ROS) and allergen content of ragweed pollen (Ambrosia artemisiifolia). Pollen was exposed to acute O(3) fumigation, with analysis of pollen viability, ROS and nitric oxide (NO) content, activity of nicotinamide adenine dinucleotide phosphate (NAD[P]H) oxidase, and expression of major allergens. There was decreased pollen viability after O(3) fumigation, which indicates damage to the pollen membrane system, although the ROS and NO contents were not changed or were only slightly induced, respectively. Ozone exposure induced a significant enhancement of the ROS-generating enzyme NAD(P)H oxidase. The expression of the allergen Amb a 1 was not affected by O(3), determined from the mRNA levels of the major allergens. We conclude that O(3) can increase ragweed pollen allergenicity through stimulation of ROS-generating NAD(P)H oxidase. Copyright © 2011 Elsevier Ltd. All rights reserved.

Critical role of NADPH oxidase in neuronal oxidative damage and microglia activation following traumatic brain injury.

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Quan-Guang Zhang

Full Text Available BACKGROUND: Oxidative stress is known to play an important role in the pathology of traumatic brain injury. Mitochondria are thought to be the major source of the damaging reactive oxygen species (ROS following TBI. However, recent work has revealed that the membrane, via the enzyme NADPH oxidase can also generate the superoxide radical (O(2(-, and thereby potentially contribute to the oxidative stress following TBI. The current study thus addressed the potential role of NADPH oxidase in TBI. METHODOLOGY/PRINCIPAL FINDINGS: The results revealed that NADPH oxidase activity in the cerebral cortex and hippocampal CA1 region increases rapidly following controlled cortical impact in male mice, with an early peak at 1 h, followed by a secondary peak from 24-96 h after TBI. In situ localization using oxidized hydroethidine and the neuronal marker, NeuN, revealed that the O(2(- induction occurred in neurons at 1 h after TBI. Pre- or post-treatment with the NADPH oxidase inhibitor, apocynin markedly inhibited microglial activation and oxidative stress damage. Apocynin also attenuated TBI-induction of the Alzheimer's disease proteins β-amyloid and amyloid precursor protein. Finally, both pre- and post-treatment of apocynin was also shown to induce significant neuroprotection against TBI. In addition, a NOX2-specific inhibitor, gp91ds-tat was also shown to exert neuroprotection against TBI. CONCLUSIONS/SIGNIFICANCE: As a whole, the study demonstrates that NADPH oxidase activity and superoxide production exhibit a biphasic elevation in the hippocampus and cortex following TBI, which contributes significantly to the pathology of TBI via mediation of oxidative stress damage, microglial activation, and AD protein induction in the brain following TBI.

Vortex gas lens

Science.gov (United States)

Bogdanoff, David W.; Berschauer, Andrew; Parker, Timothy W.; Vickers, Jesse E.

1989-01-01

A vortex gas lens concept is presented. Such a lens has a potential power density capability of 10 to the 9th - 10 to the 10th w/sq cm. An experimental prototype was constructed, and the divergence half angle of the exiting beam was measured as a function of the lens operating parameters. Reasonably good agreement is found between the experimental results and theoretical calculations. The expanded beam was observed to be steady, and no strong, potentially beam-degrading jets were found to issue from the ends of the lens. Estimates of random beam deflection angles to be expected due to boundary layer noise are presented; these angles are very small.

Pharmacological inhibition of NADPH oxidase protects against cisplatin induced nephrotoxicity in mice by two step mechanism.

Science.gov (United States)

Wang, Yimin; Luo, Xiao; Pan, Hao; Huang, Wei; Wang, Xueping; Wen, Huali; Shen, Kezhen; Jin, Baiye

2015-09-01

Cisplatin induced nephrotoxicity is primarily caused by ROS (Reactive Oxygen Species) induced proximal tubular cell death. NADPH oxidase is major source of ROS production by cisplatin. Here, we reported that pharmacological inhibition of NADPH oxidase by acetovanillone (obtained from medicinal herb Picrorhiza kurroa) led to reduced cisplatin nephrotoxicity in mice. In this study we used various molecular biology and biochemistry methods a clinically relevant model of nephropathy, induced by an important chemotherapeutic drug cisplatin. Cisplatin-induced nephrotoxicity was evident by histological damage from loss of the tubular structure. The damage was also marked by the increase in blood urea nitrogen, creatinine, protein nitration as well as cell death markers such as caspase 3/7 activity and DNA fragmentation. Tubular cell death by cisplatin led to pro-inflammatory response by production of TNFα and IL1β followed by leukocyte/neutrophil infiltration which resulted in new wave of ROS involving more NADPH oxidases. Cisplatin-induced markers of kidney damage such as oxidative stress, cell death, inflammatory cytokine production and nephrotoxicity were attenuated by acetovanillone. In addition to that, acetovanillone enhanced cancer cell killing efficacy of cisplatin. Thus, pharmacological inhibition of NADPH oxidase can be protective for cisplatin-induced nephrotoxicity in mice. Copyright © 2015. Published by Elsevier Ltd.

Primary anterior chamber intraocular lens for the treatment of severe crystalline lens subluxation.

Science.gov (United States)

Hoffman, Richard S; Fine, I Howard; Packer, Mark

2009-10-01

Subluxated cataractous and clear lenses are commonly treated by limbal or pars plana lensectomy followed by primary or secondary intraocular lens (IOL) implantation. Adjunctive capsular prosthetic devices have facilitated lens removal and IOL centration in these challenging cases but have also added complexity and potential complications to the procedure. Although crystalline lens extraction may be required to clear the visual axis in mild to moderate lens subluxations, we propose insertion of a primary anterior chamber IOL without lens extraction in severe subluxations when the eye is optically aphakic or can be made functionally aphakic following neodymium:YAG laser zonulysis. Two cases demonstrating this approach are presented.

Relative importance of redox buffers GSH and NAD(P)H in age-related neurodegeneration and Alzheimer disease-like mouse neurons.

Science.gov (United States)

Ghosh, Debolina; Levault, Kelsey R; Brewer, Gregory J

2014-08-01

Aging, a major risk factor in Alzheimer's disease (AD), is associated with an oxidative redox shift, decreased redox buffer protection, and increased free radical reactive oxygen species (ROS) generation, probably linked to mitochondrial dysfunction. While NADH is the ultimate electron donor for many redox reactions, including oxidative phosphorylation, glutathione (GSH) is the major ROS detoxifying redox buffer in the cell. Here, we explored the relative importance of NADH and GSH to neurodegeneration in aging and AD neurons from nontransgenic and 3xTg-AD mice by inhibiting their synthesis to determine whether NADH can compensate for the GSH loss to maintain redox balance. Neurons stressed by either depleting NAD(P)H or GSH indicated that NADH redox control is upstream of GSH levels. Further, although depletion of NAD(P)H or GSH correlated linearly with neuron death, compared with GSH depletion, higher neurodegeneration was observed when NAD(P)H was extrapolated to zero, especially in old age, and in the 3xTg-AD neurons. We also observed an age-dependent loss of gene expression of key redox-dependent biosynthetic enzymes, NAMPT (nicotinamide phosphoribosyltransferase), and NNT (nicotinamide nucleotide transhydrogenase). Moreover, age-related correlations between brain NNT or NAMPT gene expression and NADPH levels suggest that these genes contribute to the age-related declines in NAD(P)H. Our data indicate that in aging and more so in AD-like neurons, NAD(P)H redox control is upstream of GSH and an oxidative redox shift that promotes neurodegeneration. Thus, NAD(P)H generation may be a more efficacious therapeutic target upstream of GSH and ROS. © 2014 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

NADPH-Thioredoxin Reductase C Mediates the Response to Oxidative Stress and Thermotolerance in the Cyanobacterium Anabaena sp PCC7120

NARCIS (Netherlands)

Sanchez-Riego, Ana M.; Mata-Cabana, Alejandro; Galmozzi, CarlaV.; Florencio, Francisco J.

2016-01-01

NADPH-thioredoxin reductase C (NTRC) is a bimodular enzyme composed of an NADPH-thioredoxin reductase and a thiioredoxin domain extension in the same protein. In plants, NTRC has been described to be involved in the protection of the chloroplast against oxidative stress damage through reduction of

Capsular 'pits' in the human lens.

OpenAIRE

Harris, M. L.; Brown, N. A.; Shun-Shin, G. A.; Smith, G. T.

1992-01-01

The lens capsule is an atypical basement membrane surrounding the lens epithelial cells and lens fibres which make up the remainder of the human lens. A seemingly unreported morphological change visible in the lens capsule with the biomicroscope is described.

A high excitation magnetic quadrupole lens quadruplet incorporating a single octupole lens for a low spherical aberration probe forming lens system

Science.gov (United States)

Dou, Yanxin; Jamieson, David N.; Liu, Jianli; Li, Liyi

2018-03-01

This paper describes the design of a new probe forming lens system consisting of a high excitation magnetic quadrupole lens quadruplet that incorporates a single magnetic octupole lens. This system achieves both a high demagnification and a low spherical aberration compared to conventional high excitation systems and is intended for deployment for the Harbin 300 MeV proton microprobe for applications in space science and ion beam therapy. This relative simplicity of the ion optical design to include a single octupole lens minimizes the risks associated with the constructional and operational precision usually needed for the probe forming lens system and this system could also be deployed in microprobe systems that operate with less magnetically rigid ions. The design of the new system is validated with reference to two independent ion optical computer codes.

Objective lens

Science.gov (United States)

Olczak, Eugene G. (Inventor)

2011-01-01

An objective lens and a method for using same. The objective lens has a first end, a second end, and a plurality of optical elements. The optical elements are positioned between the first end and the second end and are at least substantially symmetric about a plane centered between the first end and the second end.

Fructose increases corticosterone production in association with NADPH metabolism alterations in rat epididymal white adipose tissue.

Science.gov (United States)

Prince, Paula D; Santander, Yanina A; Gerez, Estefania M; Höcht, Christian; Polizio, Ariel H; Mayer, Marcos A; Taira, Carlos A; Fraga, Cesar G; Galleano, Monica; Carranza, Andrea

2017-08-01

Metabolic syndrome is an array of closely metabolic disorders that includes glucose intolerance/insulin resistance, central obesity, dyslipidemia, and hypertension. Fructose, a highly lipogenic sugar, has profound metabolic effects in adipose tissue, and has been associated with the etiopathology of many components of the metabolic syndrome. In adipocytes, the enzyme 11 β-HSD1 amplifies local glucocorticoid production, being a key player in the pathogenesis of central obesity and metabolic syndrome. 11 β-HSD1 reductase activity is dependent on NADPH, a cofactor generated by H6PD inside the endoplasmic reticulum. Our focus was to explore the effect of fructose overload on epididymal white adipose tissue (EWAT) machinery involved in glucocorticoid production and NADPH and oxidants metabolism. Male Sprague-Dawley rats fed with a fructose solution (10% (w/v) in tap water) during 9 weeks developed some characteristic features of metabolic syndrome, such as hypertriglyceridemia, and hypertension. In addition, high levels of plasma and EWAT corticosterone were detected. Activities and expressions of H6PD and 11 β-HSD1, NAPDH content, superoxide anion production, expression of NADPH oxidase 2 subunits, and indicators of oxidative metabolism were measured. Fructose overloaded rats showed an increased potential in oxidant production respect to control rats. In parallel, in EWAT from fructose overloaded rats we found higher expression/activity of H6PD and 11 β-HSD1, and NADPH/NADP + ratio. Our in vivo results support that fructose overload installs in EWAT conditions favoring glucocorticoid production through higher H6PD expression/activity supplying NADPH for enhanced 11 β-HSD1 expression/activity, becoming this tissue a potential extra-adrenal source of corticosterone under these experimental conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

H2O2 and NADPH oxidases involve in regulation of 2-(2-phenylethyl)chromones accumulation during salt stress in Aquilaria sinensis calli.

Science.gov (United States)

Wang, Xiaohui; Dong, Xianjuan; Feng, Yingying; Liu, Xiao; Wang, Jinling; Zhang, Zhongxiu; Li, Jun; Zhao, Yunfang; Shi, Shepo; Tu, Pengfei

2018-04-01

2-(2-Phenylethyl)chromones are the main compounds responsible for the quality of agarwood, which is widely used in traditional medicines, incenses and perfumes. H 2 O 2 and NADPH oxidases (also known as respiratory burst oxidase homologs, Rbohs) mediate diverse physiological and biochemical processes in environmental stress responses. However, little is known about the function of H 2 O 2 and NADPH oxidases in 2-(2-phenylethyl)chromones accumulation. In this study, we found that salt stress induced a transient increase in content of H 2 O 2 and 2-(2-phenylethyl)chromones accumulation in Aquilaria sinensis calli. Exogenous H 2 O 2 remarkably decreased the production of 2-(2-phenylethyl)chromones, while dimethylthiourea (DMTU), a scavenger of H 2 O 2 , significantly increased 2-(2-phenylethyl)chromones accumulation in salt treated calli. Three new H 2 O 2 -generating genes, named AsRbohA-C, were isolated and characterized from A. sinensis. Salt stress also induced a transient increase in AsRbohA-C expression and NADPH oxidase activity. Furthermore, exogenous H 2 O 2 increased AsRbohA-C expression and NADPH oxidase activity, while DMTU inhibited AsRbohA-C expression and NADPH oxidase activity under salt stress. Moreover, diphenylene iodonium (DPI), the inhibitor of NADPH oxidases, reduced AsRbohA-C expression and NADPH oxidase activity, but significantly induced 2-(2-phenylethyl)chromones accumulation during salt stress. These results clearly demonstrated the central role of H 2 O 2 and NADPH oxidases in regulation of salt-induced 2-(2-phenylethyl)chromones accumulation in A. sinensis calli. Copyright © 2018 Elsevier B.V. All rights reserved.

Contact Lens Care

Science.gov (United States)

... Consumers Consumer Information by Audience For Women Contact Lens Care Share Tweet Linkedin Pin it More sharing ... www.fda.gov/medwatch Learn More about Contact Lens Care Other Tips on Contact Lenses Decorative Contact ...

Oxygen transport through soft contact lens and cornea: Lens characterization and metabolic modeling

Science.gov (United States)

Chhabra, Mahendra

The human cornea requires oxygen to sustain metabolic processes critical for its normal functioning. Any restriction to corneal oxygen supply from the external environment (e.g., by wearing a low oxygen-permeability contact lens) can lead to hypoxia, which may cause corneal edema (swelling), limbal hyperemia, neovascularization, and corneal acidosis. The need for adequate oxygen to the cornea is a major driving force for research and development of hypertransmissible soft contact lenses (SCLs). Currently, there is no standard technique for measuring oxygen permeability (Dk) of hypertransmissible silicone-hydrogel SCLs. In this work, an electrochemistry-based polarographic apparatus was designed, built, and operated to measure oxygen permeability in hypertransmissible SCLs. Unlike conventional methods where a range of lens thickness is needed for determining oxygen permeabilities of SCLs, this apparatus requires only a single lens thickness. The single-lens permeameter provides a reliable, efficient, and economic tool for measuring oxygen permeabilities of commercial hypertransmissible SCLs. The single-lens permeameter measures not only the product Dk, but, following modification, it measures separately diffusivity, D, and solubility, k, of oxygen in hypertransmissible SCLs. These properties are critical for designing better lens materials that ensure sufficient oxygen supply to the cornea. Metabolism of oxygen in the cornea is influenced by contact-lens-induced hypoxia, diseases such as diabetes, surgery, and drug treatment, Thus, estimation of the in-vivo corneal oxygen consumption rate is essential for gauging adequate oxygen supply to the cornea. Therefore, we have developed an unsteady-state reactive-diffusion model for the cornea-contact-lens system to determine in-vivo human corneal oxygen-consumption rate. Finally, a metabolic model was developed to determine the relation between contact-lens oxygen transmissibility (Dk/L) and corneal oxygen deficiency. A

Crystalline lens power and refractive error.

Science.gov (United States)

Iribarren, Rafael; Morgan, Ian G; Nangia, Vinay; Jonas, Jost B

2012-02-01

To study the relationships between the refractive power of the crystalline lens, overall refractive error of the eye, and degree of nuclear cataract. All phakic participants of the population-based Central India Eye and Medical Study with an age of 50+ years were included. Calculation of the refractive lens power was based on distance noncycloplegic refractive error, corneal refractive power, anterior chamber depth, lens thickness, and axial length according to Bennett's formula. The study included 1885 subjects. Mean refractive lens power was 25.5 ± 3.0 D (range, 13.9-36.6). After adjustment for age and sex, the standardized correlation coefficients (β) of the association with the ocular refractive error were highest for crystalline lens power (β = -0.41; P lens opacity grade (β = -0.42; P lens power (β = -0.95), lower corneal refractive power (β = -0.76), higher lens thickness (β = 0.30), deeper anterior chamber (β = 0.28), and less marked nuclear lens opacity (β = -0.05). Lens thickness was significantly lower in eyes with greater nuclear opacity. Variations in refractive error in adults aged 50+ years were mostly influenced by variations in axial length and in crystalline lens refractive power, followed by variations in corneal refractive power, and, to a minor degree, by variations in lens thickness and anterior chamber depth.

Characteristics of the thick, compound refractive lens

International Nuclear Information System (INIS)

Pantell, Richard H.; Feinstein, Joseph; Beguiristain, H. Raul; Piestrup, Melvin A.; Gary, Charles K.; Cremer, Jay T.

2003-01-01

A compound refractive lens (CRL), consisting of a series of N closely spaced lens elements each of which contributes a small fraction of the total focusing, can be used to focus x rays or neutrons. The thickness of a CRL can be comparable to its focal length, whereupon a thick-lens analysis must be performed. In contrast with the conventional optical lens, where the ray inside the lens follows a straight line, the ray inside the CRL is continually changing direction because of the multiple refracting surfaces. Thus the matrix representation for the thick CRL is quite different from that for the thick optical lens. Principal planes can be defined such that the thick-lens matrix can be converted to that of a thin lens. For a thick lens the focal length is greater than for a thin lens with the same lens curvature, but this lengthening effect is less for the CRL than for the conventional optical lens

TU-E-201-01: Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionists

Energy Technology Data Exchange (ETDEWEB)

Rehani, M. [Massachusetts General Hospital (United States)

2015-06-15

Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

TU-E-201-01: Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionists

International Nuclear Information System (INIS)

Rehani, M.

2015-01-01

Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

DISSECTING THE GRAVITATIONAL LENS B1608+656. I. LENS POTENTIAL RECONSTRUCTION

NARCIS (Netherlands)

Suyu, S. H.; Marshall, P. J.; Blandford, R. D.; Fassnacht, C. D.; Koopmans, L. V. E.; McKean, J. P.; Treu, T.

2009-01-01

Strong gravitational lensing is a powerful technique for probing galaxy mass distributions and for measuring cosmological parameters. Lens systems with extended source-intensity distributions are particularly useful for this purpose since they provide additional constraints on the lens potential (

Crystallization and preliminary X-ray analysis of 5-keto-d-gluconate reductase from Gluconobacter suboxydans IFO12528 complexed with 5-keto-d-gluconate and NADPH

International Nuclear Information System (INIS)

Kubota, Keiko; Miyazono, Ken-ichi; Nagata, Koji; Toyama, Hirohide; Matsushita, Kazunobu; Tanokura, Masaru

2010-01-01

NADPH-dependent 5-keto-d-gluconate reductase from G. suboxydans IFO12528 (5KGR) was expressed, purified and crystallized with 5-keto-d-gluconate and NADPH using the sitting-drop vapour-diffusion method. Crystals of the 5KGR–NADPH complex and of the 5KGR–NADPH–5-keto-d-gluconate complex diffracted X-rays to 1.75 and 2.26 Å resolution, respectively. NADPH-dependent 5-keto-d-gluconate reductase from Gluconobacter suboxydans IFO12528 (5KGR) catalyzes oxidoreduction between 5-keto-d-gluconate and d-gluconate with high specificity. 5KGR was expressed in Escherichia coli, purified and crystallized with 5-keto-d-gluconate and NADPH using the sitting-drop vapour-diffusion method at 288 K. A crystal of the 5KGR–NADPH complex was obtained using reservoir solution containing PEG 4000 as a precipitant and diffracted X-rays to 1.75 Å resolution. The crystal of the complex belonged to space group P4 2 2 1 2, with unit-cell parameters a = b = 128.6, c = 62.9 Å. A crystal of the 5KGR–NADPH–5-keto-d-gluconate complex was prepared by soaking the 5KGR–NADPH complex crystal in reservoir solution supplemented with 100 mM 5-keto-d-gluconate and 10 mM NADPH for 20 min and diffracted X-rays to 2.26 Å resolution. The crystal of the ternary complex belonged to space group P4 2 2 1 2, with unit-cell parameters a = b = 128.7, c = 62.5 Å. Both crystals contained two molecules in the asymmetric unit

Intraocular lens fabrication

Energy Technology Data Exchange (ETDEWEB)

Salazar, Mike A. (Albuquerque, NM); Foreman, Larry R. (Los Alamos, NM)

1997-01-01

This invention describes a method for fabricating an intraocular lens made rom clear Teflon.TM., Mylar.TM., or other thermoplastic material having a thickness of about 0.025 millimeters. These plastic materials are thermoformable and biocompatable with the human eye. The two shaped lenses are bonded together with a variety of procedures which may include thermosetting and solvent based adhesives, laser and impulse welding, and ultrasonic bonding. The fill tube, which is used to inject a refractive filling material is formed with the lens so as not to damage the lens shape. A hypodermic tube may be included inside the fill tube.

Neutrophils to the ROScue: Mechanisms of NADPH Oxidase Activation and Bacterial Resistance

Directory of Open Access Journals (Sweden)

Giang T. Nguyen

2017-08-01

Full Text Available Reactive oxygen species (ROS generated by NADPH oxidase play an important role in antimicrobial host defense and inflammation. Their deficiency in humans results in recurrent and severe bacterial infections, while their unregulated release leads to pathology from excessive inflammation. The release of high concentrations of ROS aids in clearance of invading bacteria. Localization of ROS release to phagosomes containing pathogens limits tissue damage. Host immune cells, like neutrophils, also known as PMNs, will release large amounts of ROS at the site of infection following the activation of surface receptors. The binding of ligands to G-protein-coupled receptors (GPCRs, toll-like receptors, and cytokine receptors can prime PMNs for a more robust response if additional signals are encountered. Meanwhile, activation of Fc and integrin directly induces high levels of ROS production. Additionally, GPCRs that bind to the bacterial-peptide analog fMLP, a neutrophil chemoattractant, can both prime cells and trigger low levels of ROS production. Engagement of these receptors initiates intracellular signaling pathways, resulting in activation of downstream effector proteins, assembly of the NADPH oxidase complex, and ultimately, the production of ROS by this complex. Within PMNs, ROS released by the NADPH oxidase complex can activate granular proteases and induce the formation of neutrophil extracellular traps (NETs. Additionally, ROS can cross the membranes of bacterial pathogens and damage their nucleic acids, proteins, and cell membranes. Consequently, in order to establish infections, bacterial pathogens employ various strategies to prevent restriction by PMN-derived ROS or downstream consequences of ROS production. Some pathogens are able to directly prevent the oxidative burst of phagocytes using secreted effector proteins or toxins that interfere with translocation of the NADPH oxidase complex or signaling pathways needed for its activation

Straylight Measurements in Contact Lens Wear

NARCIS (Netherlands)

van der Meulen, Ivanka J. E.; Engelbrecht, Leonore A.; van Vliet, Johannes M. J.; Lapid-Gortzak, Ruth; Nieuwendaal, Carla P.; Mourits, Maarten P.; Schlingemann, Reinier O.; van den Berg, Thomas J. T. P.

2010-01-01

Purpose: (1) To quantify the effect of contact lens wear on straylight in rigid and soft contact lens wearers and (2) to relate findings to morphological changes and subjective complaints. Methods: Straylight was measured using the Oculus C-Quant during contact lens wear and after contact lens

Changes in pH and NADPH regulate the DNA binding activity of neuronal PAS domain protein 2, a mammalian circadian transcription factor.

Science.gov (United States)

Yoshii, Katsuhiro; Tajima, Fumihisa; Ishijima, Sumio; Sagami, Ikuko

2015-01-20

Neuronal PAS domain protein 2 (NPAS2) is a core clock transcription factor that forms a heterodimer with BMAL1 to bind the E-box in the promoter of clock genes and is regulated by various environmental stimuli such as heme, carbon monoxide, and NAD(P)H. In this study, we investigated the effects of pH and NADPH on the DNA binding activity of NPAS2. In an electrophoretic mobility shift (EMS) assay, the pH of the reaction mixture affected the DNA binding activity of the NPAS2/BMAL1 heterodimer but not that of the BMAL1/BMAL1 homodimer. A change in pH from 7.0 to 7.5 resulted in a 1.7-fold increase in activity in the absence of NADPH, and NADPH additively enhanced the activity up to 2.7-fold at pH 7.5. The experiments using truncated mutants revealed that N-terminal amino acids 1-61 of NPAS2 were sufficient to sense the change in both pH and NADPH. We further analyzed the kinetics of formation and DNA binding of the NPAS2/BMAL1 heterodimer at various pH values. In the absence of NADPH, a change in pH from 6.5 to 8.0 decreased the KD(app) value of the E-box from 125 to 22 nM, with an 8-fold increase in the maximal level of DNA binding for the NPAS2/BMAL1 heterodimer. The addition of NADPH resulted in a further decrease in KD(app) to 9 nM at pH 8.0. Furthermore, NPAS2-dependent transcriptional activity in a luciferase assay using NIH3T3 cells also increased with the pH of the culture medium. These results suggest that NPAS2 has a role as a pH and metabolite sensor in regulating circadian rhythms.

Replacing Escherichia coli NAD-dependent glyceraldehyde 3-phosphate dehydrogenase (GAPDH) with a NADP-dependent enzyme from Clostridium acetobutylicum facilitates NADPH dependent pathways.

Science.gov (United States)

Martínez, Irene; Zhu, Jiangfeng; Lin, Henry; Bennett, George N; San, Ka-Yiu

2008-11-01

Reactions requiring reducing equivalents, NAD(P)H, are of enormous importance for the synthesis of industrially valuable compounds such as carotenoids, polymers, antibiotics and chiral alcohols among others. The use of whole-cell biocatalysis can reduce process cost by acting as catalyst and cofactor regenerator at the same time; however, product yields might be limited by cofactor availability within the cell. Thus, our study focussed on the genetic manipulation of a whole-cell system by modifying metabolic pathways and enzymes to improve the overall production process. In the present work, we genetically engineered an Escherichia coli strain to increase NADPH availability to improve the productivity of products that require NADPH in its biosynthesis. The approach involved an alteration of the glycolysis step where glyceraldehyde-3-phosphate (GAP) is oxidized to 1,3 bisphophoglycerate (1,3-BPG). This reaction is catalyzed by NAD-dependent endogenous glyceraldehyde-3-phosphate dehydrogenase (GAPDH) encoded by the gapA gene. We constructed a recombinant E. coli strain by replacing the native NAD-dependent gapA gene with a NADP-dependent GAPDH from Clostridium acetobutylicum, encoded by the gene gapC. The beauty of this approach is that the recombinant E. coli strain produces 2 mol of NADPH, instead of NADH, per mole of glucose consumed. Metabolic flux analysis showed that the flux through the pentose phosphate (PP) pathway, one of the main pathways that produce NADPH, was reduced significantly in the recombinant strain when compared to that of the parent strain. The effectiveness of the NADPH enhancing system was tested using the production of lycopene and epsilon-caprolactone as model systems using two different background strains. The recombinant strains, with increased NADPH availability, consistently showed significant higher productivity than the parent strains.

Quadrupole magnetic lens

International Nuclear Information System (INIS)

Piskunov, V.A.

1981-01-01

The following connection of windings of electromagnet is suggested for simplification of the design of qUadrupole magnetic lens intended for use in radiotechnical and electron-optical devices. The mentioned windings are connected with each other by a bridge scheme and the variable resistors are switched in its diagonals in the lens containing four electromagnet with windings connected with two variable resistors the mobile contacts of which are connected with a direct current source. Current redistribution between left windings and right windings takes place at shift of mobile contact of variable resistor, and current redistribution between upper and low coils of electromagnets takes place at shifting mobile contact of the other variable resistor. In this case smooth and independent electron-optical misalignment of lens by two mutually perpendicular directions proceeds. Use of the given design of the lens in the oscillograph permits to use printing assembly for alignment plate and to reduce the number of connections at the expense of decreasing the number of resistors

Contact lens surface by electron beam

International Nuclear Information System (INIS)

Shin, Jung Hyuck; Lee, Suk Ju; Hwang, Kwang Ha; Jeon Jin

2011-01-01

Contact lens materials needs good biocompatibility, high refractive index, high optical transparency, high water content etc. Surface treat method by using plasma and radiation can modify the physical and/or chemical properties of the contact lens surface. Radiation technology such as electron beam irradiation can apply to polymerization reaction and enhance the functionality of the polymer.The purpose of this study is to modify of contact lens surface by using Eb irradiation technology. Electron beam was irradiated to the contact lens surface which was synthesized thermal polymerization method and commercial contact lens to modify physical and chemical properties. Ft-IR, XP, UV-vis spectrophotometer, water content, oxygen trans-metastability were used to characterize the surface state, physicochemical, and optical property of the contact lens treated with Eb. The water content and oxygen transmissibility of the contact lens treated with Eb were increased due to increase in the hydrophilic group such as O-C=O and OH group on the contact lens surface which could be produced by possible reaction between carbon and oxygen during the Eb irradiation. All of the lenses showed the high optical transmittance above 90%. In this case of B/Es, TES, Ti contact lens, the optical transmittance decreased about 5% with increasing Eb dose in the wavelength of UV-B region. The contact lens modified by Eb irradiation could improve the physical properties of the contact lens such as water content and oxygen transmissibility

Properties of the cathode lens combined with a focusing magnetic/immersion-magnetic lens

International Nuclear Information System (INIS)

Konvalina, I.; Muellerova, I.

2011-01-01

The cathode lens is an electron optical element in an emission electron microscope accelerating electrons from the sample, which serves as a source for a beam of electrons. Special application consists in using the cathode lens first for retardation of an illuminating electron beam and then for acceleration of reflected as well as secondary electrons, made in the directly imaging low energy electron microscope or in its scanning version discussed here. In order to form a real image, the cathode lens has to be combined with a focusing magnetic lens or a focusing immersion-magnetic lens, as used for objective lenses of some commercial scanning electron microscopes. These two alternatives are compared with regards to their optical properties, in particular with respect to predicted aberration coefficients and the spot size, as well as the optimum angular aperture of the primary beam. The important role of the final aperture size on the image resolution is also presented.

NADPH Oxidase-Mediated ROS Production Determines Insulin's Action on the Retinal Microvasculature.

Science.gov (United States)

Kida, Teruyo; Oku, Hidehiro; Horie, Taeko; Matsuo, Junko; Kobayashi, Takatoshi; Fukumoto, Masanori; Ikeda, Tsunehiko

2015-10-01

To determine whether insulin induces nitric oxide (NO) formation in retinal microvessels and to examine the effects of high glucose on the formation of NO. Freshly isolated rat retinal microvessels were incubated in normal (5.5 mM) or high (20 mM) glucose with or without insulin (100 nM). The levels of insulin-induced NO and reactive oxygen species (ROS) in the retinal microvessels were determined semiquantitatively using fluorescent probes, 4,5-diaminofluorescein diacetate, and hydroethidine, respectively, and a laser scanning confocal microscope. The insulin-induced changes of NO in rat retinal endothelial cells and pericytes cultured at different glucose concentrations (5.5 and 25 mM) were determined using flow cytometry. Nitric oxide synthase (NOS) protein levels were determined by Western blot analysis; intracellular levels of ROS were determined using fluorescence-activated cell sorting (FACS) analysis of ethidium fluorescence; and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase RNA expression was quantified using real-time PCR. Exposure of microvessels to insulin under normal glucose conditions led to a significant increase in NO levels; however, this increase was significantly suppressed when the microvessels were incubated under high glucose conditions. Intracellular levels of ROS were significantly increased in both retinal microvessels and cultured microvascular cells under high glucose conditions. The expression of NOS and NADPH oxidase were significantly increased in endothelial cells and pericytes under high glucose conditions. The increased formation of NO by insulin and its suppression by high glucose conditions suggests that ROS production mediated by NADPH oxidase is important by insulin's effect on the retinal microvasculature.

Intraocular lens fabrication

Energy Technology Data Exchange (ETDEWEB)

Salazar, M.A.; Foreman, L.R.

1997-07-08

This invention describes a method for fabricating an intraocular lens made from clear Teflon{trademark}, Mylar{trademark}, or other thermoplastic material having a thickness of about 0.025 millimeters. These plastic materials are thermoformable and biocompatable with the human eye. The two shaped lenses are bonded together with a variety of procedures which may include thermosetting and solvent based adhesives, laser and impulse welding, and ultrasonic bonding. The fill tube, which is used to inject a refractive filling material is formed with the lens so as not to damage the lens shape. A hypodermic tube may be included inside the fill tube. 13 figs.

21 CFR 886.1375 - Bagolini lens.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bagolini lens. 886.1375 Section 886.1375 Food and... OPHTHALMIC DEVICES Diagnostic Devices § 886.1375 Bagolini lens. (a) Identification. A Bagolini lens is a device that consists of a plane lens containing almost imperceptible striations that do not obscure...

The lens and cataracts.

Science.gov (United States)

Matthews, Andrew G

2004-08-01

It is conservatively estimated that some form of lens opacity is present in 5% to 7% of horses with otherwise clinically normal eyes.These opacities can range from small epicapsular remnants of the fetal vasculature to dense and extensive cataract. A cataract is defined technically as any opacity or alteration in the optical homogeneity of the lens involving one or more of the following: anterior epithelium, capsule, cortex, or nucleus. In the horse, cataracts rarely involve the entire lens structure (ie, complete cataracts) and are more usually localized to one anatomic landmark or sector of the lens. Complete cataracts are invariably associated with overt and significant visual disability. Focal or incomplete cataracts alone seldom cause any apparent visual dysfunction in affected horses,however.

UVA Light-excited Kynurenines Oxidize Ascorbate and Modify Lens Proteins through the Formation of Advanced Glycation End Products

Science.gov (United States)

Linetsky, Mikhail; Raghavan, Cibin T.; Johar, Kaid; Fan, Xingjun; Monnier, Vincent M.; Vasavada, Abhay R.; Nagaraj, Ram H.

2014-01-01

Advanced glycation end products (AGEs) contribute to lens protein pigmentation and cross-linking during aging and cataract formation. In vitro experiments have shown that ascorbate (ASC) oxidation products can form AGEs in proteins. However, the mechanisms of ASC oxidation and AGE formation in the human lens are poorly understood. Kynurenines are tryptophan oxidation products produced from the indoleamine 2,3-dioxygenase (IDO)-mediated kynurenine pathway and are present in the human lens. This study investigated the ability of UVA light-excited kynurenines to photooxidize ASC and to form AGEs in lens proteins. UVA light-excited kynurenines in both free and protein-bound forms rapidly oxidized ASC, and such oxidation occurred even in the absence of oxygen. High levels of GSH inhibited but did not completely block ASC oxidation. Upon UVA irradiation, pigmented proteins from human cataractous lenses also oxidized ASC. When exposed to UVA light (320–400 nm, 100 milliwatts/cm2, 45 min to 2 h), young human lenses (20–36 years), which contain high levels of free kynurenines, lost a significant portion of their ASC content and accumulated AGEs. A similar formation of AGEs was observed in UVA-irradiated lenses from human IDO/human sodium-dependent vitamin C transporter-2 mice, which contain high levels of kynurenines and ASC. Our data suggest that kynurenine-mediated ASC oxidation followed by AGE formation may be an important mechanism for lens aging and the development of senile cataracts in humans. PMID:24798334

A Tribute to Len Barton

Science.gov (United States)

Tomlinson, Sally

2010-01-01

This article constitutes a short personal tribute to Len Barton in honour of his work and our collegial relationship going back over 30 years. It covers how Len saw his intellectual project of providing critical sociological and political perspectives on special education, disability and inclusion, and his own radical political perspectives. Len's…

Photosensitized oxidation in the ocular lens: evidence for photosensitizers endogenous to the human lens

International Nuclear Information System (INIS)

Zigler, J.S. Jr.; Goosey, J.D.

1981-01-01

Numerous investigators have attempted to associate near UV light exposure with various changes which occur to lens crystallins during aging and cataractogenesis. Recently it was shown that in vitro singlet oxygen mediated oxidation of lens crystallins produces effects very similar to those documented for crystallins from old or cataractous lenses and it was suggested that near UV photodynamic effects may play a major role in vivo in aging in the human lens. It has now been shown that certain oxidation products of tryptophan which have been identified in human lens can act as near UV photosensitizers, producing singlet oxygen. The insoluble protein fraction from human cataracts was shown to have the capacity to act as a photosensitizer. An age-related increase in photosensitizing capacity was also demonstrated in the soluble crystallins from human lens. These findings are discussed with respect to development of pigmented nuclear cataracts. (author)

NADPH-dependent D-aldose reductases and xylose fermentation in Fusarium oxysporum

DEFF Research Database (Denmark)

Panagiotou, Gianni; Christakopoulos, P.

2004-01-01

Two aldose (xylose) reductases (ARI and ARII) from Fusarium oxysporum were purified and characterized. The native ARI was a monomer with M-r 41000, pI 5.2 and showed a 52-fold preference for NADPH over NADH, while ARII was homodimeric with a subunit of M-r 37000, pI 3.6 and a 60-fold preference...

A course in lens design

CERN Document Server

Velzel, Chris

2014-01-01

A Course in Lens Design is an instruction in the design of image-forming optical systems. It teaches how a satisfactory design can be obtained in a straightforward way. Theory is limited to a minimum, and used to support the practical design work. The book introduces geometrical optics, optical instruments and aberrations. It gives a description of the process of lens design and of the strategies used in this process. Half of its content is devoted to the design of sixteen types of lenses, described in detail from beginning to end. This book is different from most other books on lens design because it stresses the importance of the initial phases of the design process: (paraxial) lay-out and (thin-lens) pre-design. The argument for this change of accent is that in these phases much information can be obtained about the properties of the lens to be designed. This information can be used in later phases of the design. This makes A Course in Lens Design a useful self-study book, and a suitable basis for an intro...

Development of Fresnel lens for improvement of rear visibility; Shikai kojo Fresnel lens no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Iwamoto, K; Sanada, C; Tsukino, M [Nissan Motor Co. Ltd., Tokyo (Japan)

1997-10-01

Fresnel lenses have been widely used to increase the visual field around vehicles for drivers. However, internal reflection in these lenses has been an obstacle in producing dear images. This internal glow is generated by incident light from an unexpected direction reflecting on the non-lens surface or radiating from the non-lens surface of the Fresnel lens. The cause of internal glow has been made dear combining louver film with the lens. The newly developed technology removes obstacles in producing dear images by reducing internal glow. 7 figs.

Vitrectorhexis and lens aspiration with posterior chamber intraocular lens implantation in spherophakia.

Science.gov (United States)

Al-Haddad, Christiane; Khatib, Lama

2012-07-01

We describe a technique that uses the vitrector to perform successful lens aspiration and posterior chamber intraocular lens (IOL) implantation in children with spherophakia and anterior lens subluxation. After an anterior chamber maintainer is placed, the ocutome is introduced through a limbal incision to perform a circular vitrectorhexis to avoid excessive manipulation of the unstable lens followed by gentle cortex aspiration. A foldable IOL is injected into the sulcus (3-piece IOL) or bag (1-piece IOL) if the capsule is sufficiently stable. Through a pars plana incision, the ocutome is then used to perform a posterior capsulotomy to prevent late posterior capsule opacification. In our patient, sulcus IOL placement was more stable than in-the-bag placement. Neither author has a financial or proprietary interest in any material or method mentioned. Copyright © 2012 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Conformational changes of the NADPH-dependent cytochrome P450 reductase in the course of electron transfer to cytochromes P450

DEFF Research Database (Denmark)

Laursen, Tomas; Jensen, Kenneth; Møller, Birger Lindberg

2011-01-01

The NADPH-dependent cytochrome P450 reductase (CPR) is a key electron donor to eucaryotic cytochromes P450 (CYPs). CPR shuttles electrons from NADPH through the FAD and FMN-coenzymes into the iron of the prosthetic heme-group of the CYP. In the course of these electron transfer reactions, CPR und...... to serve as an effective electron transferring "nano-machine"....

Pentacam Scheimpflug quantitative imaging of the crystalline lens and intraocular lens.

Science.gov (United States)

Rosales, Patricia; Marcos, Susana

2009-05-01

To implement geometrical and optical distortion correction methods for anterior segment Scheimpflug images obtained with a commercially available system (Pentacam, Oculus Optikgeräte GmbH). Ray tracing algorithms were implemented to obtain corrected ocular surface geometry from the original images captured by the Pentacam's CCD camera. As details of the optical layout were not fully provided by the manufacturer, an iterative procedure (based on imaging of calibrated spheres) was developed to estimate the camera lens specifications. The correction procedure was tested on Scheimpflug images of a physical water cell model eye (with polymethylmethacrylate cornea and a commercial IOL of known dimensions) and of a normal human eye previously measured with a corrected optical and geometrical distortion Scheimpflug camera (Topcon SL-45 [Topcon Medical Systems Inc] from the Vrije University, Amsterdam, Holland). Uncorrected Scheimpflug images show flatter surfaces and thinner lenses than in reality. The application of geometrical and optical distortion correction algorithms improves the accuracy of the estimated anterior lens radii of curvature by 30% to 40% and of the estimated posterior lens by 50% to 100%. The average error in the retrieved radii was 0.37 and 0.46 mm for the anterior and posterior lens radii of curvature, respectively, and 0.048 mm for lens thickness. The Pentacam Scheimpflug system can be used to obtain quantitative information on the geometry of the crystalline lens, provided that geometrical and optical distortion correction algorithms are applied, within the accuracy of state-of-the art phakometry and biometry. The techniques could improve with exact knowledge of the technical specifications of the instrument, improved edge detection algorithms, consideration of aspheric and non-rotationally symmetrical surfaces, and introduction of a crystalline gradient index.

Luneburg lens in silicon photonics.

Science.gov (United States)

Di Falco, Andrea; Kehr, Susanne C; Leonhardt, Ulf

2011-03-14

The Luneburg lens is an aberration-free lens that focuses light from all directions equally well. We fabricated and tested a Luneburg lens in silicon photonics. Such fully-integrated lenses may become the building blocks of compact Fourier optics on chips. Furthermore, our fabrication technique is sufficiently versatile for making perfect imaging devices on silicon platforms.

Crystalline lens and refractive development.

Science.gov (United States)

Iribarren, Rafael

2015-07-01

Individual refractive errors usually change along lifespan. Most children are hyperopic in early life. This hyperopia is usually lost during growth years, leading to emmetropia in adults, but myopia also develops in children during school years or during early adult life. Those subjects who remain emmetropic are prone to have hyperopic shifts in middle life. And even later, at older ages, myopic shifts are developed with nuclear cataract. The eye grows from 15 mm in premature newborns to approximately 24 mm in early adult years, but, in most cases, refractions are maintained stable in a clustered distribution. This growth in axial length would represent a refractive change of more than 40 diopters, which is compensated by changes in corneal and lens powers. The process which maintains the balance between the ocular components of refraction during growth is still under study. As the lens power cannot be measured in vivo, but can only be calculated based on the other ocular components, there have not been many studies of lens power in humans. Yet, recent studies have confirmed that the lens loses power during growth in children, and that hyperopic and myopic shifts in adulthood may be also produced by changes in the lens. These studies in children and adults give a picture of the changing power of the lens along lifespan. Other recent studies about the growth of the lens and the complexity of its internal structure give clues about how these changes in lens power are produced along life. Copyright © 2015 Elsevier Ltd. All rights reserved.

Stereo-specificity for pro-(R) hydrogen of NAD(P)H during enzyme-catalyzed hydride transfer to CL-20

International Nuclear Information System (INIS)

Bhushan, Bharat; Halasz, Annamaria; Hawari, Jalal

2005-01-01

A dehydrogenase from Clostridium sp. EDB2 and a diaphorase from Clostridium kluyveri were reacted with CL-20 to gain insights into the enzyme-catalyzed hydride transfer to CL-20, and the enzyme's stereo-specificity for either pro-R or pro-S hydrogens of NAD(P)H. Both enzymes biotransformed CL-20 at rates of 18.5 and 24 nmol/h/mg protein, using NADH and NADPH as hydride-source, respectively, to produce a N-denitrohydrogenated product with a molecular weight of 393 Da. In enzyme kinetics studies using reduced deuterated pyridine nucleotides, we found a kinetic deuterium isotopic effect of 2-fold on CL-20 biotransformation rate using dehydrogenase enzyme against (R)NADD as a hydride-source compared to either (S)NADD or NADH. Whereas, in case of diaphorase, the kinetic deuterium isotopic effect of about 1.5-fold was observed on CL-20 biotransformation rate using (R)NADPD as hydride-source. In a comparative study with LC-MS, using deuterated and non-deuterated NAD(P)H, we found a positive mass-shift of 1 Da in the N-denitrohydrogenated product suggesting the involvement of a deuteride (D - ) transfer from NAD(P)D. The present study thus revealed that both dehydrogenase and diaphorase enzymes from the two Clostridium species catalyzed a hydride transfer to CL-20 and showed stereo-specificity for pro-R hydrogen of NAD(P)H

Modern lens antennas for communications engineering

CERN Document Server

Thornton, John

2012-01-01

The aim of this book is to present the modern design principles and analysis of lens antennas. It gives graduates and RF/Microwave professionals the design insights in order to make full use of lens antennas.  Why do we want to write a book in lens antennas? Because this topic has not been thoroughly publicized, its importance is underestimated. As antennas play a key role in communication systems, recent development in wireless communications would indeed benefit from the characteristics of lens antennas: low profile, and low cost etc.  The major advantages of lens antennas are na

NADPH Oxidase Contributes to Resistance against Aggregatibacter actinomycetemcomitans-Induced Periodontitis in Mice.

Science.gov (United States)

Bast, Antje; Kubis, Helen; Holtfreter, Birte; Ribback, Silvia; Martin, Heiner; Schreiner, Helen C; Dominik, Malte J; Breitbach, Katrin; Dombrowski, Frank; Kocher, Thomas; Steinmetz, Ivo

2017-02-01

Aggregatibacter actinomycetemcomitans is a Gram-negative commensal bacterium of the oral cavity which has been associated with the pathogenesis of periodontitis with severe alveolar bone destruction. The role of host factors such as reactive oxygen and nitrogen intermediates in periodontal A. actinomycetemcomitans infection and progression to periodontitis is still ill-defined. Therefore, this study aimed to analyze the role of NADPH oxidase and inducible nitric oxide synthase (iNOS) in a murine model of A. actinomycetemcomitans-induced periodontitis. NADPH oxidase-deficient (gp91 phox knockout [KO]), iNOS-deficient (iNOS KO), and C57BL/6 wild-type mice were orally infected with A. actinomycetemcomitans and analyzed for bacterial colonization at various time points. Alveolar bone mineral density and alveolar bone volume were quantified by three-dimensional micro-computed tomography, and the degree of tissue inflammation was calculated by histological analyses. At 5 weeks after infection, A. actinomycetemcomitans persisted at significantly higher levels in the murine oral cavities of infected gp91 phox KO mice than in those of iNOS KO and C57BL/6 mice. Concomitantly, alveolar bone mineral density was significantly lower in all three infected groups than in uninfected controls, but with the highest loss of bone density in infected gp91 phox KO mice. Only infected gp91 phox KO mice revealed significant loss of alveolar bone volume and enhanced inflammatory cell infiltration, as well as an increased number of osteoclasts. Our results indicate that NADPH oxidase is important to control A. actinomycetemcomitans infection in the murine oral cavity and to prevent subsequent alveolar bone destruction and osteoclastogenesis. Copyright © 2017 American Society for Microbiology.

Changes in monkey crystalline lens spherical aberration during simulated accommodation in a lens stretcher.

Science.gov (United States)

Maceo Heilman, Bianca; Manns, Fabrice; de Castro, Alberto; Durkee, Heather; Arrieta, Esdras; Marcos, Susana; Parel, Jean-Marie

2015-02-10

The purpose of this study was to quantify accommodation-induced changes in the spherical aberration of cynomolgus monkey lenses. Twenty-four lenses from 20 cynomolgus monkeys (Macaca fascicularis; 4.4-16.0 years of age; postmortem time 13.5 ± 13.0 hours) were mounted in a lens stretcher. Lens spherical aberration was measured in the unstretched (accommodated) and stretched (relaxed) states with a laser ray tracing system that delivered 51 equally spaced parallel rays along 1 meridian of the lens over the central 6-mm optical zone. A camera mounted below the lens was used to measure the ray height at multiple positions along the optical axis. For each entrance ray, the change in ray height with axial position was fitted with a third-order polynomial. The effective paraxial focal length and Zernike spherical aberration coefficients corresponding to a 6-mm pupil diameter were extracted from the fitted values. The unstretched lens power decreased with age from 59.3 ± 4.0 diopters (D) for young lenses to 45.7 ± 3.1 D for older lenses. The unstretched lens shifted toward less negative spherical aberration with age, from -6.3 ± 0.7 μm for young lenses to -5.0 ± 0.5 μm for older lenses. The power and spherical aberration of lenses in the stretched state were independent of age, with values of 33.5 ± 3.4 D and -2.6 ± 0.5 μm, respectively. Spherical aberration is negative in cynomolgus monkey lenses and becomes more negative with accommodation. These results are in good agreement with the predicted values using computational ray tracing in a lens model with a reconstructed gradient refractive index. The spherical aberration of the unstretched lens becomes less negative with age. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.

Symmetric lens with extended depth of focus

OpenAIRE

Cho, Sung Nae

2008-01-01

The lens surface profile is derived based on the instantaneous focal length versus the lens radius data. The lens design based on instantaneous focal length versus the lens radius data has many useful applications in software assisted image focusing technology.

Urotensin II inhibits skeletal muscle glucose transport signaling pathways via the NADPH oxidase pathway.

Directory of Open Access Journals (Sweden)

Hong-Xia Wang

Full Text Available Our previous studies have demonstrated that the urotensin (UII and its receptor are up-regulated in the skeletal muscle of mice with type II diabetes mellitus (T2DM, but the significance of UII in skeletal muscle insulin resistance remains unknown. The purpose of this study was to investigate the effect of UII on NADPH oxidase and glucose transport signaling pathways in the skeletal muscle of mice with T2DM and in C2C12 mouse myotube cells. KK/upj-AY/J mice (KK mice were divided into the following groups: KK group, with saline treatment for 2 weeks; KK+ urantide group, with daily 30 µg/kg body weight injections over the same time period of urantide, a potent urotensin II antagonist peptide; Non-diabetic C57BL/6J mice were used as normal controls. After urantide treatment, mice were subjected to an intraperitoneal glucose tolerance test, in addition to measurements of the levels of ROS, NADPH oxidase and the phosphorylated AKT, PKC and ERK. C2C12 cells were incubated with serum-free DMEM for 24 hours before conducting the experiments, and then administrated with 100 nM UII for 2 hours or 24 hours. Urantide treatment improved glucose tolerance, decreased the translocation of the NADPH subunits p40-phox and p47-phox, and increased levels of the phosphorylated PKC, AKT and ERK. In contrast, UII treatment increased ROS production and p47-phox and p67-phox translocation, and decreased the phosphorylated AKT, ERK1/2 and p38MAPK; Apocynin abrogated this effect. In conclusion, UII increased ROS production by NADPH oxidase, leading to the inhibition of signaling pathways involving glucose transport, such as AKT/PKC/ERK. Our data imply a role for UII at the molecular level in glucose homeostasis, and possibly in skeletal muscle insulin resistance in T2DM.

[Congenital lens subluxation: visual acuity outcomes and intraocular lens postoperative position].

Science.gov (United States)

Arraes, Caroline; Endriss, Daniela; Lobato, Francisco; Arraes, João; Ventura, Marcelo

2010-01-01

To evaluate the visual acuity outcomes and to investigate the intraocular lens (IOL) and endocapsular ring positions with ultrasound biomicroscopy in 17 eyes of 10 patients with congenital lens subluxation who underwent the same surgical technique, by the same surgeon. The study was performed in the ''Hospital de Olhos de Pernambuco'' and ''Fundação Altino Ventura''. The surgical technique consisted of phacoaspiration with implant of endocapsular ring and intraocular lens with one loop haptic amputated. The age varied from 7 to 22 years. Data on visual acuity (VA) before and after surgery, surgery follow-up period, and complications were analyzed. All patients underwent ultrasound biomicroscopy. The mean follow-up period was 2.8 years. There was a VA improvement in 17 (100%) eyes: in 12 eyes (70.6%) the visual acuity was better than 20/40; 4 (23.5%) ranged from 20/40 to 20/100, and 1 (5.9%) had visual acuity worse than 20/100, however better than the preoperative visual acuity. The posterior capsular opacification occurred in 10 eyes (58.9%). Ultrasound biomicroscopy showed that all IOL were partially decentralized, however without surpassing the pupil border limit. Endocapsular ring position was correct and there was a good capsular support in all cases. The evaluated surgical treatment provided good intraocular lens and endocapsular ring position, with VA improvement Thus, this technique is a viable, effective and safe option for the visual rehabilitation of patients with congenital lens subluxation.

Priming of the neutrophil NADPH oxidase activation: role of p47phox phosphorylation and NOX2 mobilization to the plasma membrane.

Science.gov (United States)

El-Benna, Jamel; Dang, Pham My-Chan; Gougerot-Pocidalo, Marie-Anne

2008-07-01

Neutrophils play an essential role in host defense against microbial pathogens and in the inflammatory reaction. Upon activation, neutrophils produce superoxide anion (O*2), which generates other reactive oxygen species (ROS) such as hydrogen peroxide (H2O2), hydroxyl radical (OH*) and hypochlorous acid (HOCl), together with microbicidal peptides and proteases. The enzyme responsible for O2* production is called the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase or respiratory burst oxidase. This multicomponent enzyme system is composed of two trans-membrane proteins (p22phox and gp91phox/NOX2, which form the cytochrome b558), three cytosolic proteins (p47phox, p67phox, p40phox) and a GTPase (Rac1 or Rac2), which assemble at membrane sites upon cell activation. NADPH oxidase activation in phagocytes can be induced by a large number of soluble and particulate factors. Three major events accompany NAPDH oxidase activation: (1) protein phosphorylation, (2) GTPase activation, and (3) translocation of cytosolic components to the plasma membrane to form the active enzyme. Actually, the neutrophil NADPH oxidase exists in different states: resting, primed, activated, or inactivated. The resting state is found in circulating blood neutrophils. The primed state can be induced by neutrophil adhesion, pro-inflammatory cytokines, lipopolysaccharide, and other agents and has been characterized as a "ready to go" state, which results in a faster and higher response upon exposure to a second stimulus. The active state is found at the inflammatory or infection site. Activation is induced by the pathogen itself or by pathogen-derived formylated peptides and other agents. Finally, inactivation of NADPH oxidase is induced by anti-inflammatory agents to limit inflammation. Priming is a "double-edged sword" process as it contributes to a rapid and efficient elimination of the pathogens but can also induce the generation of large quantities of toxic ROS by hyperactivation of

Sildenafil promotes eNOS activation and inhibits NADPH oxidase in the transgenic sickle cell mouse penis.

Science.gov (United States)

Musicki, Biljana; Bivalacqua, Trinity J; Champion, Hunter C; Burnett, Arthur L

2014-02-01

Sickle cell disease (SCD)-associated vasculopathy in the penis is characterized by aberrant nitric oxide and phosphodiesterase (PDE) 5 signaling, and by increased oxidative stress. Preliminary clinical trials show that continuous treatment with PDE5 inhibitor sildenafil unassociated with sexual activity decreases priapic activity in patients with SCD. However, the mechanism of its vasculoprotective effect in the penis remains unclear. We evaluated whether continuous administration of PDE5 inhibitor sildenafil promotes eNOS function at posttranslational levels and decreases superoxide-producing enzyme NADPH oxidase activity in the sickle cell mouse penis. SCD transgenic mice were used as an animal model of SCD. WT mice served as controls. Mice received treatment with the PDE5 inhibitor sildenafil (100 mg/kg/day) or vehicle for 3 weeks. eNOS phosphorylation on Ser-1177 (positive regulatory site), eNOS interactions with heat-shock protein 90 (HSP90) (positive regulator), phosphorylated AKT (upstream mediator of eNOS phosphorylation on Ser-1177), an NADPH oxidase catalytic subunit gp91(phox), and a marker of oxidative stress (4-hydroxy-2-nonenal [HNE]) were measured by Western blot. Effect of continuous sildenafil treatment on eNOS posttranslational activation, NADPH oxidase catalytic subunit, and oxidative stress in the penis of the sickle cell mouse. Continuous treatment with sildenafil reversed (P penis. Sildenafil treatment of WT mice did not affect any of these parameters. Our findings that sildenafil enhances eNOS activation and inhibits NADPH oxidase function in the sickle cell mouse penis offers a vasculoprotective molecular basis for the therapeutic effect of sildenafil in the penis in association with SCD. © 2013 International Society for Sexual Medicine.

The influence of end of day silicone hydrogel daily disposable contact lens fit on ocular comfort, physiology and lens wettability.

Science.gov (United States)

Wolffsohn, James; Hall, Lee; Mroczkowska, Stephanie; Hunt, Olivia A; Bilkhu, Paramdeep; Drew, Tom; Sheppard, Amy

2015-10-01

To quantify the end-of-day silicone-hydrogel daily disposable contact lens fit and its influence of on ocular comfort, physiology and lens wettability. Thirty-nine subjects (22.1±3.5 years) were randomised to wear each of 3 silicone-hydrogel daily-disposable contact lenses (narafilcon A, delefilcon A and filcon II 3), bilaterally, for one week. Lens fit was assessed objectively using a digital video slit-lamp at 8, 12 and 16h after lens insertion. Hyperaemia, non-invasive tear break-up time, tear meniscus height and comfort were also evaluated at these timepoints, while corneal and conjunctival staining were assessed on lens removal. Lens fit assessments were not different between brands (P>0.05), with the exception of the movement at blink where narafilcon A was more mobile. Overall, lag reduced but push-up speed increased from 8 to 12h (P0.05). Movement-on-blink was unaffected by wear-time (F=0.403, P=0.670). A more mobile lens fit with one brand did not indicate that person would have a more mobile fit with another brand (r=-0.06 to 0.63). Lens fit was not correlated with comfort, ocular physiology or lens wettability (P>0.01). Among the lenses tested, objective lens fit changed between 8h and 12h of lens wear. The weak correlation in individual lens fit between brands indicates that fit is dependent on more than ocular shape. Consequently, substitution of a different lens brand with similar parameters will not necessarily provide comparable lens fit. Copyright © 2015 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Unique role of NADPH oxidase 5 in oxidative stress in human renal proximal tubule cells

Directory of Open Access Journals (Sweden)

Peiying Yu

2014-01-01

Full Text Available NADPH oxidases are the major sources of reactive oxygen species in cardiovascular, neural, and kidney cells. The NADPH oxidase 5 (NOX5 gene is present in humans but not rodents. Because Nox isoforms in renal proximal tubules (RPTs are involved in the pathogenesis of hypertension, we tested the hypothesis that NOX5 is differentially expressed in RPT cells from normotensive (NT and hypertensive subjects (HT. We found that NOX5 mRNA, total NOX5 protein, and apical membrane NOX5 protein were 4.2±0.7-fold, 5.2±0.7-fold, and 2.8±0.5-fold greater in HT than NT. Basal total NADPH oxidase activity was 4.5±0.2-fold and basal NOX5 activity in NOX5 immunoprecipitates was 6.2±0.2-fold greater in HT than NT (P=<0.001, n=6–14/group. Ionomycin increased total NOX and NOX5 activities in RPT cells from HT (P<0.01, n=4, ANOVA, effects that were abrogated by pre-treatment of the RPT cells with diphenylene-iodonium or superoxide dismutase. Silencing NOX5 using NOX5-siRNA decreased NADPH oxidase activity (−45.1±3.2% vs. mock-siRNA, n=6–8 in HT. D1-like receptor stimulation decreased NADPH oxidase activity to a greater extent in NT (−32.5±1.8% than HT (−14.8±1.8. In contrast to the marked increase in expression and activity of NOX5 in HT, NOX1 mRNA and protein were minimally increased in HT, relative to NT; total NOX2 and NOX4 proteins were not different between HT and NT, while the increase in apical RPT cell membrane NOX1, NOX2, and NOX4 proteins in HT, relative to NT, was much less than those observed with NOX5. Thus, we demonstrate, for the first time, that NOX5 is expressed in human RPT cells and to greater extent than the other Nox isoforms in HT than NT. We suggest that the increased expression of NOX5, which may be responsible for the increased oxidative stress in RPT cells in human essential hypertension, is caused, in part, by a defective renal dopaminergic system.

NADPH oxidase AtrbohD and AtrbohF genes function in ROS-dependent ABA signaling in Arabidopsis

Science.gov (United States)

Kwak, June M.; Mori, Izumi C.; Pei, Zhen-Ming; Leonhardt, Nathalie; Torres, Miguel Angel; Dangl, Jeffery L.; Bloom, Rachel E.; Bodde, Sara; Jones, Jonathan D.G.; Schroeder, Julian I.

2003-01-01

Reactive oxygen species (ROS) have been proposed to function as second messengers in abscisic acid (ABA) signaling in guard cells. However, the question whether ROS production is indeed required for ABA signal transduction in vivo has not yet been addressed, and the molecular mechanisms mediating ROS production during ABA signaling remain unknown. Here, we report identification of two partially redundant Arabidopsis guard cell-expressed NADPH oxidase catalytic subunit genes, AtrbohD and AtrbohF, in which gene disruption impairs ABA signaling. atrbohD/F double mutations impair ABA-induced stomatal closing, ABA promotion of ROS production, ABA-induced cytosolic Ca2+ increases and ABA- activation of plasma membrane Ca2+-permeable channels in guard cells. Exogenous H2O2 rescues both Ca2+ channel activation and stomatal closing in atrbohD/F. ABA inhibition of seed germination and root elongation are impaired in atrbohD/F, suggesting more general roles for ROS and NADPH oxidases in ABA signaling. These data provide direct molecular genetic and cell biological evidence that ROS are rate-limiting second messengers in ABA signaling, and that the AtrbohD and AtrbohF NADPH oxidases function in guard cell ABA signal transduction. PMID:12773379

Structures of Saccharomyces cerevisiae D-arabinose dehydrogenase Ara1 and its complex with NADPH: implications for cofactor-assisted substrate recognition.

Science.gov (United States)

Hu, Xiao-Qian; Guo, Peng-Chao; Ma, Jin-Di; Li, Wei-Fang

2013-11-01

The primary role of yeast Ara1, previously mis-annotated as a D-arabinose dehydrogenase, is to catalyze the reduction of a variety of toxic α,β-dicarbonyl compounds using NADPH as a cofactor at physiological pH levels. Here, crystal structures of Ara1 in apo and NADPH-complexed forms are presented at 2.10 and 2.00 Å resolution, respectively. Ara1 exists as a homodimer, each subunit of which adopts an (α/β)8-barrel structure and has a highly conserved cofactor-binding pocket. Structural comparison revealed that induced fit upon NADPH binding yielded an intact active-site pocket that recognizes the substrate. Moreover, the crystal structures combined with computational simulation defined an open substrate-binding site to accommodate various substrates that possess a dicarbonyl group.

Application of NAD(P)H oxidase for cofactor regeneration in dehydrogenase catalyzed oxidations

DEFF Research Database (Denmark)

Rehn, Gustav; Pedersen, Asbjørn Toftgaard; Woodley, John

2016-01-01

alcohol dehydrogenases. However, their effective use requires an effective regeneration of the oxidized nicotinamide cofactor (NAD(P)+), which is critical for the economic feasibility of the process. NAD(P)H oxidase is an enzyme class of particular interest for this cofactor regeneration since it enables...

Structure of 1-deoxy-d-xylulose 5-phosphate reductoisomerase in a quaternary complex with a magnesium ion, NADPH and the antimalarial drug fosmidomycin

International Nuclear Information System (INIS)

Yajima, Shunsuke; Hara, Kodai; Iino, Daisuke; Sasaki, Yasuyuki; Kuzuyama, Tomohisa; Ohsawa, Kanju; Seto, Haruo

2007-01-01

The crystal structure of 1-deoxy-d-xylulose 5-phosphate reductoisomerase (DXR) from Escherichia coli complexed with Mg 2+ , NADPH and fosmidomycin was determined at 2.2 Å resolution. The structure showed a well defined loop conformation at the active site of DXR. The crystal structure of 1-deoxy-d-xylulose 5-phosphate reductoisomerase (DXR) from Escherichia coli complexed with Mg 2+ , NADPH and fosmidomycin was solved at 2.2 Å resolution. DXR is the key enzyme in the 2-C-methyl-d-erythritol 4-phosphate pathway and is an effective target of antimalarial drugs such as fosmidomycin. In the crystal structure, electron density for the flexible loop covering the active site was clearly observed, indicating the well ordered conformation of DXR upon substrate binding. On the other hand, no electron density was observed for the nicotinamide-ribose portion of NADPH and the position of Asp149 anchoring Mg 2+ was shifted by NADPH in the active site

Positive correlation between decreased cellular uptake, NADPH-glutathione reductase activity and adriamycin resistance in Ehrlich ascites tumor lines.

Science.gov (United States)

Scheulen, M E; Hoensch, H; Kappus, H; Seeber, S; Schmidt, C G

1987-01-01

From a wild type strain of Ehrlich ascites tumor (EATWT) sublines resistant to daunorubicin (EATDNM), etoposide (EATETO), and cisplatinum (EATCIS) have been developed in vivo. Increase in survival and cure rate caused by adriamycin (doxorubicin) have been determined in female NMRI mice which were inoculated i.p. with EAT cells. Adriamycin concentrations causing 50% inhibition of 3H-thymidine (ICT) and 3H-uridine incorporation (ICU) and intracellular adriamycin steady-state concentrations (SSC) were measured in vitro. Adriamycin resistance increased and SSC decreased in the following sequence: EATWT - EATCIS - EATDNM - EATETO. When ICT and ICU were corrected for intracellular adriamycin concentrations in consideration of the different SSC (ICTc, ICUc), ICTc and ICUc still varied up to the 3.2 fold in EATCIS, EATDNM and EATETO in comparison to EATWT. Thus, in addition to different SSC other factors must be responsible for adriamycin resistance. Therefore, enzymes which may play a role in the cytotoxicity related to adriamycin metabolism (NADPH-cytochrome P-450 reductase, NADPH-glutathione reductase, NADP-glucose-6-phosphate dehydrogenase, NADP-isocitrate dehydrogenase) were measured. In contrast to the other parameters determined, NADPH-glutathione reductase was significantly (p less than 0.01) increased up to the 3.2 fold parallel to adriamycin resistance as determined by increase in life span, cure rate, ICTc, and ICUc, respectively. It is concluded that high activities of NADPH-glutathione reductase may contribute to an increase in adriamycin resistance of malignant tumors.

Refractive lens exchange with a multifocal diffractive aspheric intraocular lens

Directory of Open Access Journals (Sweden)

Teresa Ferrer-Blasco

2012-06-01

Full Text Available PURPOSE: To evaluate the safety, efficacy and predictability after refractive lens exchange with multifocal diffractive aspheric intraocular lens implantation. METHODS: Sixty eyes of 30 patients underwent bilateral implantation with AcrySof® ReSTOR® SN6AD3 intraocular lens with +4.00 D near addition. Patients were divided into myopic and hyperopic groups. Monocular best corrected visual acuity at distance and near and monocular uncorrected visual acuity at distance and near were measured before and 6 months postoperatively. RESULTS: After surgery, uncorrected visual acuity was 0.08 ± 0.15 and 0.11 ± 0.14 logMAR for the myopic and hyperopic groups, respectively (50% and 46.67% of patients had an uncorrected visual acuity of 20/20 or better in the myopic and hyperopic groups, respectively. The safety and efficacy indexes were 1.05 and 0.88 for the myopic and 1.01 and 0.86 for the hyperopic groups at distance vision. Within the myopic group, 20 eyes remained unchanged after the surgery, and 3 gained >2 lines of best corrected visual acuity. For the hyperopic group, 2 eyes lost 2 lines of best corrected visual acuity, 21 did not change, and 3 eyes gained 2 lines. At near vision, the safety and efficacy indexes were 1.23 and 1.17 for the myopic and 1.16 and 1.13 for the hyperopic groups. Best corrected near visual acuity improved after surgery in both groups (from 0.10 logMAR to 0.01 logMAR in the myopic group, and from 0.10 logMAR to 0.04 logMAR in the hyperopic group. CONCLUSIONS: The ReSTOR® SN6AD3 intraocular lens in refractive lens exchange demonstrated good safety, efficacy, and predictability in correcting high ametropia and presbyopia.

21 CFR 886.5844 - Prescription spectacle lens.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Prescription spectacle lens. 886.5844 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5844 Prescription spectacle lens. (a) Identification. A prescription spectacle lens is a glass or plastic device that is a lens intended to be worn by...

fMLP-Induced IL-8 Release Is Dependent on NADPH Oxidase in Human Neutrophils

Directory of Open Access Journals (Sweden)

María A. Hidalgo

2015-01-01

Full Text Available N-Formyl-methionyl-leucyl-phenylalanine (fMLP and platelet-activating factor (PAF induce similar intracellular signalling profiles; but only fMLP induces interleukin-8 (IL-8 release and nicotinamide adenine dinucleotide phosphate reduced (NADPH oxidase activity in neutrophils. Because the role of ROS on IL-8 release in neutrophils is until now controversial, we assessed if NADPH oxidase is involved in the IL-8 secretions and PI3K/Akt, MAPK, and NF-κB pathways activity induced by fMLP. Neutrophils were obtained from healthy volunteers. IL-8 was measured by ELISA, IL-8 mRNA by qPCR, and ROS production by luminol-amplified chemiluminescence, reduction of ferricytochrome c, and FACS. Intracellular pH changes were detected by spectrofluorescence. ERK1/2, p38 MAPK, and Akt phosphorylation were analysed by immunoblotting and NF-κB was analysed by immunocytochemistry. Hydroxy-3-methoxyaceto-phenone (HMAP, diphenyleneiodonium (DPI, and siRNA Nox2 reduced the ROS and IL-8 release in neutrophils treated with fMLP. HMAP, DPI, and amiloride (a Na+/H+ exchanger inhibitor inhibited the Akt phosphorylation and did not affect the p38 MAPK and ERK1/2 activity. DPI and HMAP reduced NF-κB translocation induced by fMLP. We showed that IL-8 release induced by fMLP is dependent on NADPH oxidase, and ROS could play a redundant role in cell signalling, ultimately activating the PI3K/Akt and NF-κB pathways in neutrophils.

Extra virgin olive oil rich in polyphenols modulates VEGF-induced angiogenic responses by preventing NADPH oxidase activity and expression.

Science.gov (United States)

Calabriso, Nadia; Massaro, Marika; Scoditti, Egeria; D'Amore, Simona; Gnoni, Antonio; Pellegrino, Mariangela; Storelli, Carlo; De Caterina, Raffaele; Palasciano, Giuseppe; Carluccio, Maria Annunziata

2016-02-01

Previous studies have shown the antiinflammatory, antioxidant and antiangiogenic properties by pure olive oil polyphenols; however, the effects of olive oil phenolic fraction on the inflammatory angiogenesis are unknown. In this study, we investigated the effects of the phenolic fraction (olive oil polyphenolic extract, OOPE) from extra virgin olive oil and related circulating metabolites on the VEGF-induced angiogenic responses and NADPH oxidase activity and expression in human cultured endothelial cells. We found that OOPE (1-10 μg/ml), at concentrations achievable nutritionally, significantly reduced, in a concentration-dependent manner, the VEGF-induced cell migration, invasiveness and tube-like structure formation through the inhibition of MMP-2 and MMP-9. OOPE significantly (Pextra virgin olive oil, with high polyphenol content, decreased VEGF-induced NADPH oxidase activity and Nox4 expression, as well as, MMP-9 expression, as compared with fasting control serum. Overall, native polyphenols and serum metabolites of extra virgin olive oil rich in polyphenols are able to lower the VEGF-induced angiogenic responses by preventing endothelial NADPH oxidase activity and decreasing the expression of selective NADPH oxidase subunits. Our results provide an alternative mechanism by which the consumption of olive oil rich in polyphenols may account for a reduction of oxidative stress inflammatory-related sequelae associated with chronic degenerative diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

Plasma Lens for Muon and Neutrino Beams

International Nuclear Information System (INIS)

Kahn, S.A.; Korenev, S.; Bishai, M.; Diwan, M.; Gallardo, J.C.; Hershcovitch, A.; Johnson, B.M.

2008-01-01

The plasma lens is examined as an alternate to focusing horns and solenoids for use in a neutrino or muon beam facility. The plasma lens concept is based on a combined high-energy lens/target configuration. The current is fed at electrodes located upstream and downstream from the target where pion capturing is needed. The current flows primarily in the plasma, which has a lower resistivity than the target. A second plasma lens section, with an additional current feed, follows the target to provide shaping of the plasma for optimum focusing. The plasma lens is immersed in an additional solenoid magnetic field to facilitate the plasma stability. The geometry of the plasma is shaped to provide optimal pion capture. Simulations of this plasma lens system have shown a 25% higher neutrino production than the horn system. Plasma lenses have the additional advantage of negligible pion absorption and scattering by the lens material and reduced neutrino contamination during anti-neutrino running. Results of particle simulations using plasma lens will be presented

Mechanism of the reaction catalyzed by dihydrofolate reductase from Escherichia coli: pH and deuterium isotope effects with NADPH as the variable substrate

International Nuclear Information System (INIS)

Morrison, J.F.; Stone, S.R.

1988-01-01

The variations with pH of the kinetic parameters and primary deuterium isotope effects for the reaction of NADPH with dihydrofolate reductase from Escherichia coli have been determined. The aims of the investigations were to elucidate the chemical mechanism of the reaction and to obtain information about the location of the rate-limiting steps. The V and V/K/sub NADPH/ profiles indicate that a single ionizing group at the active center of the enzyme must be protonated for catalysis, whereas the K/sub i/ profiles show that the binding of NADPH to the free enzyme and of ATP-ribose to the enzyme-dihydrofolate complex is pH independent. From the results of deuterium isotope effects on V/K/sub NADPH/, it is concluded that NADPH behaves as a sticky substrate. It is this stickiness that raises artificially the intrinsic pK value of 6.4 for the Asp-27 residue of the enzyme-dihydrofolate complex to an observed value of 8.9. Thus, the binary enzyme complex is largely protonated at neutral pH. The elevation of the intrinsic pK value of 6.4 for the ternary enzyme-NADPH-dihydrofolate complex to 8.5 is not due to the kinetic effects of substrates. Rather, it is the consequence of the lower, pH-independent rate of product release and the faster pH-dependent catalytic step. The data for deuterium isotope and deuterium solvent isotope effects are consistent with the postulate that, for the reduction of dihydrofolate to tetrahydrofolate, protonation precedes hydride transfer. A scheme is proposed for the indirect transfer of a proton from the enzyme to dihydrofolate

Axotomy increases NADPH-diaphorase activity in the dorsal root ganglia and lumbar spinal cord of the turtle Trachemys dorbigni

OpenAIRE

Partata,W.A.; Krepsky,A.M.R.; Marques,M.; Achaval,M.

1999-01-01

Seven days after transection of the sciatic nerve NADPH-diaphorase activity increased in the small and medium neurons of the dorsal root ganglia of the turtle. However, this increase was observed only in medium neurons for up to 90 days. At this time a bilateral increase of NADPH-diaphorase staining was observed in all areas and neuronal types of the dorsal horn, and in positive motoneurons in the lumbar spinal cord, ipsilateral to the lesion. A similar increase was also demonstrable in spina...

Lens decenter and tilt measurement by interferogram

Science.gov (United States)

Hung, Min-Wei; Wu, Wen-Hong; Huang, Kuo-Cheng

2009-11-01

For the recent years, the vigorous development of the electro-optic industry, particularly the digital camera and the cellular phone camera, has placed a larger and larger demand for the optical devices. Among the optical lens, the aspherical optical lens plays the key component because the aspherical lens may provide better imaging quality then the spherical lens does. For the manufacturing reason, the aspherical lens is prone to a decenter or tilt issue with respect to the optical axes of its two surfaces. To measure decenter and tile error specifically would help to obviate the deficient lens, but most of the present measuring method can't provide this function. This paper proposed a new method to specifically measure the decenter and tile of lens by observing the interferogram of each surface. And the corresponding measuring instrument, which contains interferometer and motion stages, was introduced as well.

Clinical study of foldable intraocular lens secondary implantation after lens-vitrectomy in residual capsular with traumatic eyes

Directory of Open Access Journals (Sweden)

Ru-Fa Meng

2015-07-01

Full Text Available AIM: To investigate the operation methods and clinical effects of foldable intraocular lens secondary implantation after lens-vitrectomy in residual capsular with traumatic eyes.METHODS: During January 2012 to January 2014, foldable intraocular lens was implanted on 47 cases following lens-vitrectomy in residual capsular with traumatic eyes 3～6mo. Follow-up period was 6～12mo, averaged(8.21±2.63mo. RESULTS:All of 47 eyes had successful operation at one time, and position deviation was not appeared. The naked vision of the last postoperative follow-up was(0.44±0.19. Compared with best corrected visual acuity(0.41±0.23, and There was no significant difference between visual acuity of preoperative and last follow-up period(t=0.879, P=0.342. No severe complication was found. CONCLUSION: Secondary implantation of foldable intraocular lens is a safe and reliable method for correcting ametropia after lens-vitrectomy in residual capsular with traumatic eyes.

21 CFR 886.3600 - Intraocular lens.

Science.gov (United States)

2010-04-01

... DEVICES OPHTHALMIC DEVICES Prosthetic Devices § 886.3600 Intraocular lens. (a) Identification. An intraocular lens is a device made of materials such as glass or plastic intended to be implanted to replace the natural lens of an eye. (b) Classification. Class III. (c) Date PMA or notice of completion of a...

Developing the Regulatory Utility of the Exposome: Mapping Exposures for Risk Assessment through Lifestage Exposome Snapshots (LEnS).

Science.gov (United States)

Shaffer, Rachel M; Smith, Marissa N; Faustman, Elaine M

2017-08-07

Exposome-related efforts aim to document the totality of human exposures across the lifecourse. This field has advanced rapidly in recent years but lacks practical application to risk assessment, particularly for children's health. Our objective was to apply the exposome to children's health risk assessment by introducing the concept of Lifestage Exposome Snapshots (LEnS). Case studies are presented to illustrate the value of the framework. The LEnS framework encourages organization of exposome studies based on windows of susceptibility for particular target organ systems. Such analyses will provide information regarding cumulative impacts during specific critical periods of the life course. A logical extension of this framework is that regulatory standards should analyze exposure information by target organ, rather than for a single chemical only or multiple chemicals grouped solely by mechanism of action. The LEnS concept is a practical refinement to the exposome that accounts for total exposures during particular windows of susceptibility in target organ systems. Application of the LEnS framework in risk assessment and regulation will improve protection of children's health by enhancing protection of sensitive developing organ systems that are critical for lifelong health and well-being. https://doi.org/10.1289/EHP1250.

Impact of lens case hygiene guidelines on contact lens case contamination.

Science.gov (United States)

Wu, Yvonne T; Teng, Yuu Juan; Nicholas, Mary; Harmis, Najat; Zhu, Hua; Willcox, Mark D P; Stapleton, Fiona

2011-10-01

Lens case contamination is a risk factor for microbial keratitis. The effectiveness of manufacturers' lens case cleaning guidelines in limiting microbial contamination has not been evaluated in vivo. This study compared the effectiveness of manufacturers' guidelines and an alternative cleaning regimen. A randomized cross-over clinical trial with two phases (n = 40) was performed. Participants used the lens types of their choice in conjunction with the provided multipurpose solution (containing polyhexamethylene biguanide) for daily wear. In the manufacturers' guideline phase, cases were rinsed with multipurpose solution and air dried. In the alternative regimen phase, cases were rubbed, rinsed with solution, tissue wiped, and air-dried face down. The duration of each phase was 1 month. Lens cases were collected at the end of each phase for microbiological investigation. The levels of microbial contamination were compared, and compliance to both regimens was assessed. The case contamination rate was 82% (32/39) in the manufacturers' guideline group, compared with 72% (28/39) in the alternative regimen group. There were significantly fewer (p = 0.004) colony forming units (CFU) of bacteria from cases used by following the alternative regimen (CFU range of 0 to 10, and median of 12 CFU per well) compared with that of the manufacturer's guidelines (CFU range of 0 to 10, and median of 28 CFU per well). The compliance level between both guidelines was not significantly different (p > 0.05). The alternative guidelines are more effective in eliminating microbial contamination from lens cases than that of the current manufacturer's guideline. Simply incorporating rubbing and tissue-wiping steps in daily case hygiene reduces viable organism contamination.

21 CFR 886.1400 - Maddox lens.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Maddox lens. 886.1400 Section 886.1400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1400 Maddox lens. (a) Identification. A Maddox lens is a device...

Intracapsular lens extraction for the treatment of pupillary block glaucoma associated with anterior subluxation of the crystalline lens.

Science.gov (United States)

Kim, Yong Joon; Ha, Seung Joo

2013-01-01

To report a case of pupillary block glaucoma associated with spontaneous crystalline lens subluxation into the anterior chamber in a 34-year-old man. Dry vitrectomy was performed for securing enough retrolental space, and an intracapsular lens extraction was then performed via a corneolimbal incision. Additional endothelial cell damage was avoided with an injection of viscoelastics and gentle extraction of the crystalline lens. After deepening of the anterior chamber, scleral fixation of the intraocular lens was performed with an ab externo technique. Two months after the operation, a well-fixated intraocular lens was observed and intraocular pressure was stable. The postoperative corneal astigmatism was -3.5 dpt, and the patient had a best-corrected visual acuity of 20/25. Postoperative complications included decreased endothelial cell count and sector iris paralysis near the incision site. An anteriorly subluxated crystalline lens can cause pupillary block glaucoma in healthy young adults. To prevent intraoperative complications, intracapsular lens extraction with dry vitrectomy can be a good surgical option. The endothelial cell density should be closely monitored after surgery.

[The X+ chronic granulomatous disease as a fabulous model to study the NADPH oxidase complex activation].

Science.gov (United States)

Stasia, Marie-José

2007-05-01

Chronic granulomatous disease (CGD) is a rare inherited disorder in which phagocytes lack NADPH oxidase activity. Patients with CGD suffer from recurrent bacterial and fungal infections because of the absence of superoxide anions (O2- degrees ) generatingsystem. The NADPH oxidase complex is composed of a membranous cytochrome b558, cytosolic proteins p67phox, p47phox, p40phox and two small GTPases Rac2 and Rap1A. Cytochrome b558 consists of two sub-units gp91phox and p22phox. The most common form of CGD is due to mutations in CYBB gene encoding gp91phox. In some rare cases, the mutated gp91phox is normally expressed but is devoided of oxidase activity. These variants called X+ CGD, have provided interesting informations about oxidase activation mechanisms. However modelization of such variants is necessary to obtain enough biological material for studies at the molecular level. A cellular model (knock-out PLB-985 cells) has been developed for expressing recombinant mutated gp91phox for functional analysis of the oxidase complex. Recent works demonstrated that this cell line genetically deficient in gp91phox is a powerful tool for functional analysis of the NADPH oxidase complex activation.

Plasma Lens for Muon and Neutrino Beams

Science.gov (United States)

Kahn, Stephen; Korenev, Sergey; Bishai, Mary; Diwan, Milind; Gallardo, Juan; Hershcovitch, Ady; Johnson, Brant

2008-04-01

The plasma lens is examined as an alternate to focusing horns and solenoids for use in a neutrino or muon beam facility. The plasma lens concept is based on a combined high-current lens/target configuration. The current is fed at electrodes located upstream and downstream from the target where pion capturing is needed. The current flows primarily in the plasma, which has a lower resistivity than the target. A second plasma lens section, with an additional current feed, follows the target to provide shaping of the plasma stability. The geometry of the plasma is shaped to provide optimal pion capture. Simulations of this plasma lens system have shown a 25% higher neutrino production than the horn system. A plasma lens has additional advantage: larger axial current than horns, minimal neutrino contamination during antineutrino running, and negligible pion absorption or scattering. Results from particle simulations using a plasma lens will be presented.

The in vitro NADPH-dependent inhibition by CCl4 of the ATP-dependent calcium uptake of hepatic microsomes from male rats. Studies on the mechanism of the inactivation of the hepatic microsomal calcium pump by the CCl3 radical

International Nuclear Information System (INIS)

Srivastava, S.P.; Chen, N.Q.; Holtzman, J.L.

1990-01-01

The hepatotoxicity of CCl4 is mediated through its initial reduction by cytochrome P-450 to the CCl3 radical. This radical then damages important metabolic systems such as the ATP-dependent microsomal Ca2+ pump. Previous studies from our laboratory on isolated microsomes have shown that NADPH in the absence of toxic agents inhibits this pump. We have now found in in vitro incubations that CCl4 (0.5-2.5 mM) enhanced the NADPH-dependent inhibition of Ca2+ uptake from 28% without CCl4 to a maximum of 68%. These concentrations are in the range found in the livers and blood of lethally intoxicated animals and are toxic to cultured hepatocytes. The inhibition of Ca2+ uptake was due both to a decrease in the Ca2(+)-dependent ATPase and to an enhanced release of Ca2+ from the microsomes. The NADPH-dependent CCl4 inhibition was greater under N2 and was totally prevented by CO. GSH (1-10 mM) added during the incubation with CCl4 prevented the inhibition. This protection was also seen when the incubations were performed under nitrogen. When samples were preincubated with CCl4, the CCl4 metabolism was stopped, and then the Ca2+ uptake was determined; GSH reversed the CCl4 inhibition of Ca2+ uptake. This reversal showed saturation kinetics for GSH with two Km values of 0.315 and 93 microM when both the preincubation and the Ca2+ uptake were performed under air, and 0.512 and 31 microM when both were performed under nitrogen. Cysteine did not prevent the NADPH-dependent CCl4 inhibition of Ca2+ uptake. CCl4 increased lipid peroxidation in air, but no lipid peroxidation was seen under nitrogen. Lipid peroxidation was only modestly reversed by GSH. GSH did not remove 14C bound to samples preincubated with the 14CCl4

NNT reverse mode of operation mediates glucose control of mitochondrial NADPH and glutathione redox state in mouse pancreatic β-cells

Directory of Open Access Journals (Sweden)

Laila R.B. Santos

2017-06-01

Full Text Available Objective: The glucose stimulation of insulin secretion (GSIS by pancreatic β-cells critically depends on increased production of metabolic coupling factors, including NADPH. Nicotinamide nucleotide transhydrogenase (NNT typically produces NADPH at the expense of NADH and ΔpH in energized mitochondria. Its spontaneous inactivation in C57BL/6J mice was previously shown to alter ATP production, Ca2+ influx, and GSIS, thereby leading to glucose intolerance. Here, we tested the role of NNT in the glucose regulation of mitochondrial NADPH and glutathione redox state and reinvestigated its role in GSIS coupling events in mouse pancreatic islets. Methods: Islets were isolated from female C57BL/6J mice (J-islets, which lack functional NNT, and genetically close C57BL/6N mice (N-islets. Wild-type mouse NNT was expressed in J-islets by adenoviral infection. Mitochondrial and cytosolic glutathione oxidation was measured with glutaredoxin 1-fused roGFP2 probes targeted or not to the mitochondrial matrix. NADPH and NADH redox state was measured biochemically. Insulin secretion and upstream coupling events were measured under dynamic or static conditions by standard procedures. Results: NNT is largely responsible for the acute glucose-induced rise in islet NADPH/NADP+ ratio and decrease in mitochondrial glutathione oxidation, with a small impact on cytosolic glutathione. However, contrary to current views on NNT in β-cells, these effects resulted from a glucose-dependent reduction in NADPH consumption by NNT reverse mode of operation, rather than from a stimulation of its forward mode of operation. Accordingly, the lack of NNT in J-islets decreased their sensitivity to exogenous H2O2 at non-stimulating glucose. Surprisingly, the lack of NNT did not alter the glucose-stimulation of Ca2+ influx and upstream mitochondrial events, but it markedly reduced both phases of GSIS by altering Ca2+-induced exocytosis and its metabolic amplification. Conclusion: These

[Representation and mathematical analysis of human crystalline lens].

Science.gov (United States)

Tălu, Stefan; Giovanzana, Stefano; Tălu, Mihai

2011-01-01

The surface of human crystalline lens can be described and analyzed using mathematical models based on parametric representations, used in biomechanical studies and 3D solid modeling of the lens. The mathematical models used in lens biomechanics allow the study and the behavior of crystalline lens on variables and complex dynamic loads. Also, the lens biomechanics has the potential to improve the results in the development of intraocular lenses and cataract surgery. The paper presents the most representative mathematical models currently used for the modeling of human crystalline lens, both optically and biomechanically.

ONLINE MONITORING OF EXTRACELLULAR BRAIN GLUCOSE USING MICRODIALYSIS AND A NADPH-LINKED ENZYMATIC ASSAY

NARCIS (Netherlands)

VANDERKUIL, JHF; KORF, J

A method to monitor extracellular glucose in freely moving rats, based on intracerebral microdialysis coupled to an enzyme reactor is described. The dialysate is continuously mixed with a solution containing the enzymes hexokinase and glucose-6-phosphate dehydrogenase, and the fluorescence of NADPH

[Intraocular lens implantation with one loop haptic amputated: a new propose to the subluxation lens surgical treatment].

Science.gov (United States)

Ventura, Marcelo; Endriss, Daniela

2010-01-01

To evaluate the postoperative results of congenital lens subluxation corrected by a new technique. Retrospective chart review of 21 eyes of 13 patients with no traumatic lens subluxation who underwent surgery in Altino Ventura Foundation from April, 1999 to April, 2004. The mean age was 8.7 +/- 5.4 years old, and the mean follow-up period was 21.5 +/- 19.3 months. Patients underwent phacoaspiration, endocapsular ring and intraocular lens (IOL) implantation. The implanted IOL had one loop haptic excised and was supported above the ring, inside the capsular bag promoting intraocular lens centralization. Visual acuity improvement was observed in all cases. There was a significant reduction of the spherical equivalent and spherical component comparing the pre and postoperative refraction (psubluxation surgical treatment, promoting lens centralization and postoperative visual acuity improvement.

Role of Aquaporin 0 in lens biomechanics

Energy Technology Data Exchange (ETDEWEB)

Sindhu Kumari, S.; Gupta, Neha [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); Shiels, Alan [Washington University School of Medicine, St. Louis, MO (United States); FitzGerald, Paul G. [Cell Biology and Human Anatomy, School of Medicine, University of California, Davis, CA (United States); Menon, Anil G. [University of Cincinnati College of Medicine, Cincinnati, OH (United States); Mathias, Richard T. [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); SUNY Eye Institute, NY (United States); Varadaraj, Kulandaiappan, E-mail: kulandaiappan.varadaraj@stonybrook.edu [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); SUNY Eye Institute, NY (United States)

2015-07-10

Maintenance of proper biomechanics of the eye lens is important for its structural integrity and for the process of accommodation to focus near and far objects. Several studies have shown that specialized cytoskeletal systems such as the beaded filament (BF) and spectrin-actin networks contribute to mammalian lens biomechanics; mutations or deletion in these proteins alters lens biomechanics. Aquaporin 0 (AQP0), which constitutes ∼45% of the total membrane proteins of lens fiber cells, has been shown to function as a water channel and a structural cell-to-cell adhesion (CTCA) protein. Our recent ex vivo study on AQP0 knockout (AQP0 KO) mouse lenses showed the CTCA function of AQP0 could be crucial for establishing the refractive index gradient. However, biomechanical studies on the role of AQP0 are lacking. The present investigation used wild type (WT), AQP5 KO (AQP5{sup −/−}), AQP0 KO (heterozygous KO: AQP0{sup +/−}; homozygous KO: AQP0{sup −/−}; all in C57BL/6J) and WT-FVB/N mouse lenses to learn more about the role of fiber cell AQPs in lens biomechanics. Electron microscopic images exhibited decreases in lens fiber cell compaction and increases in extracellular space due to deletion of even one allele of AQP0. Biomechanical assay revealed that loss of one or both alleles of AQP0 caused a significant reduction in the compressive load-bearing capacity of the lenses compared to WT lenses. Conversely, loss of AQP5 did not alter the lens load-bearing ability. Compressive load-bearing at the suture area of AQP0{sup +/−} lenses showed easy separation while WT lens suture remained intact. These data from KO mouse lenses in conjunction with previous studies on lens-specific BF proteins (CP49 and filensin) suggest that AQP0 and BF proteins could act co-operatively in establishing normal lens biomechanics. We hypothesize that AQP0, with its prolific expression at the fiber cell membrane, could provide anchorage for cytoskeletal structures like BFs and

Role of Aquaporin 0 in lens biomechanics

International Nuclear Information System (INIS)

Sindhu Kumari, S.; Gupta, Neha; Shiels, Alan; FitzGerald, Paul G.; Menon, Anil G.; Mathias, Richard T.; Varadaraj, Kulandaiappan

2015-01-01

Maintenance of proper biomechanics of the eye lens is important for its structural integrity and for the process of accommodation to focus near and far objects. Several studies have shown that specialized cytoskeletal systems such as the beaded filament (BF) and spectrin-actin networks contribute to mammalian lens biomechanics; mutations or deletion in these proteins alters lens biomechanics. Aquaporin 0 (AQP0), which constitutes ∼45% of the total membrane proteins of lens fiber cells, has been shown to function as a water channel and a structural cell-to-cell adhesion (CTCA) protein. Our recent ex vivo study on AQP0 knockout (AQP0 KO) mouse lenses showed the CTCA function of AQP0 could be crucial for establishing the refractive index gradient. However, biomechanical studies on the role of AQP0 are lacking. The present investigation used wild type (WT), AQP5 KO (AQP5 −/− ), AQP0 KO (heterozygous KO: AQP0 +/− ; homozygous KO: AQP0 −/− ; all in C57BL/6J) and WT-FVB/N mouse lenses to learn more about the role of fiber cell AQPs in lens biomechanics. Electron microscopic images exhibited decreases in lens fiber cell compaction and increases in extracellular space due to deletion of even one allele of AQP0. Biomechanical assay revealed that loss of one or both alleles of AQP0 caused a significant reduction in the compressive load-bearing capacity of the lenses compared to WT lenses. Conversely, loss of AQP5 did not alter the lens load-bearing ability. Compressive load-bearing at the suture area of AQP0 +/− lenses showed easy separation while WT lens suture remained intact. These data from KO mouse lenses in conjunction with previous studies on lens-specific BF proteins (CP49 and filensin) suggest that AQP0 and BF proteins could act co-operatively in establishing normal lens biomechanics. We hypothesize that AQP0, with its prolific expression at the fiber cell membrane, could provide anchorage for cytoskeletal structures like BFs and together they help to

A specific p47phox -serine phosphorylated by convergent MAPKs mediates neutrophil NADPH oxidase priming at inflammatory sites

DEFF Research Database (Denmark)

Dang, Pham My-Chan; Stensballe, Allan; Boussetta, Tarek

2006-01-01

mass spectrometry to show that GM-CSF and TNF-alpha induce phosphorylation of Ser345 on p47phox, a cytosolic component of NADPH oxidase, in human neutrophils. As Ser345 is located in the MAPK consensus sequence, we tested the effects of MAPK inhibitors. Inhibitors of the ERK1/2 pathway abrogated GM......Neutrophil NADPH oxidase plays a key role in host defense and in inflammation by releasing large amounts of superoxide and other ROSs. Proinflammatory cytokines such as GM-CSF and TNF-alpha prime ROS production by neutrophils through unknown mechanisms. Here we used peptide sequencing by tandem...

Regulation of the NADPH Oxidase RBOHD During Plant Immunity.

Science.gov (United States)

Kadota, Yasuhiro; Shirasu, Ken; Zipfel, Cyril

2015-08-01

Pathogen recognition induces the production of reactive oxygen species (ROS) by NADPH oxidases in both plants and animals. ROS have direct antimicrobial properties, but also serve as signaling molecules to activate further immune outputs. However, ROS production has to be tightly controlled to avoid detrimental effects on host cells, but yet must be produced in the right amount, at the right place and at the right time upon pathogen perception. Plant NADPH oxidases belong to the respiratory burst oxidase homolog (RBOH) family, which contains 10 members in the model plant Arabidopsis thaliana. The perception of pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors (PRRs) leads to a rapid, specific and strong production of ROS, which is dependent on RBOHD. RBOHD is mainly controlled by Ca(2+) via direct binding to EF-hand motifs and phosphorylation by Ca(2+)-dependent protein kinases. Recent studies have, however, revealed a critical role for a Ca(2+)-independent regulation of RBOHD. The plasma membrane-associated cytoplasmic kinase BIK1 (BOTRYTIS-INDUCED KINASE1), which is a direct substrate of the PRR complex, directly interacts with and phosphorylates RBOHD upon PAMP perception. Impairment of these phosphorylation events completely abolishes the function of RBOHD in immunity. These results suggest that RBOHD activity is tightly controlled by multilayered regulations. In this review, we summarize recent advances in our understanding of the regulatory mechanisms controlling RBOHD activation. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Algorithm design of liquid lens inspection system

Science.gov (United States)

Hsieh, Lu-Lin; Wang, Chun-Chieh

2008-08-01

In mobile lens domain, the glass lens is often to be applied in high-resolution requirement situation; but the glass zoom lens needs to be collocated with movable machinery and voice-coil motor, which usually arises some space limits in minimum design. In high level molding component technology development, the appearance of liquid lens has become the focus of mobile phone and digital camera companies. The liquid lens sets with solid optical lens and driving circuit has replaced the original components. As a result, the volume requirement is decreased to merely 50% of the original design. Besides, with the high focus adjusting speed, low energy requirement, high durability, and low-cost manufacturing process, the liquid lens shows advantages in the competitive market. In the past, authors only need to inspect the scrape defect made by external force for the glass lens. As to the liquid lens, authors need to inspect the state of four different structural layers due to the different design and structure. In this paper, authors apply machine vision and digital image processing technology to administer inspections in the particular layer according to the needs of users. According to our experiment results, the algorithm proposed can automatically delete non-focus background, extract the region of interest, find out and analyze the defects efficiently in the particular layer. In the future, authors will combine the algorithm of the system with automatic-focus technology to implement the inside inspection based on the product inspective demands.

Bioinspired adaptive gradient refractive index distribution lens

Science.gov (United States)

Yin, Kezhen; Lai, Chuan-Yar; Wang, Jia; Ji, Shanzuo; Aldridge, James; Feng, Jingxing; Olah, Andrew; Baer, Eric; Ponting, Michael

2018-02-01

Inspired by the soft, deformable human eye lens, a synthetic polymer gradient refractive index distribution (GRIN) lens with an adaptive geometry and focal power has been demonstrated via multilayer coextrusion and thermoforming of nanolayered elastomeric polymer films. A set of 30 polymer nanolayered films comprised of two thermoplastic polyurethanes having a refractive index difference of 0.05 were coextruded via forced-assembly technique. The set of 30 nanolayered polymer films exhibited transmission near 90% with each film varying in refractive index by 0.0017. An adaptive GRIN lens was fabricated from a laminated stack of the variable refractive index films with a 0.05 spherical GRIN. This lens was subsequently deformed by mechanical ring compression of the lens. Variation in the optical properties of the deformable GRIN lens was determined, including 20% variation in focal length and reduced spherical aberration. These properties were measured and compared to simulated results by placido-cone topography and ANSYS methods. The demonstration of a solid-state, dynamic focal length, GRIN lens with improved aberration correction was discussed relative to the potential future use in implantable devices.

Radiation dose to the lens and cataract formation

International Nuclear Information System (INIS)

Henk, J.M.; Whitelocke, R.A.F.; Warrington, A.P.; Bessell, E.M.

1993-01-01

The purpose of this work was to determine the radiation tolerance of the lens of the eye and the incidence of radiation-induced lens changes in patients treated by fractionated supervoltage radiation therapy for orbital tumors. Forty patients treated for orbital lymphoma and pseudotumor with tumor doses of 20--40 Gy were studied. The lens was partly shielded using lead cylinders in most cases. The dose to the germinative zone of the lens was estimated by measurements in a tissue equivalent phantom using both film densitometry and thermoluminescent dosimetry. Opthalmological examination was performed at 6 monthly intervals after treatment. The lead shield was found to reduce the dose to the germinative zone of the lens to between 36--50% of the tumor dose for Cobalt beam therapy, and to between 11--18% for 5 MeV x-rays. Consequently, the lens doses were in the range 4.5--30 Gy in 10--20 fractions. Lens opacities first appeared from between 3 and 9 years after irradiation. Impairment of visual acuity ensued in 74% of the patients who developed lens opacities. The incidence of lens changes was strongly dose-related. None was seen after doses of 5 Gy or lower, whereas doses of 16.5 Gy or higher were all followed by lens opacities which impaired visual acuity. The largest number of patients received a maximum lens dose of 15 Gy; in this group the actuarial incidence of lens opacities at 8 years was 57% with visual impairment in 38%. The adult lens can tolerate a total dose of 5 Gy during a fractionated course of supervoltage radiation therapy without showing any changes. Doses of 16.5 Gy or higher will almost invariably lead to visual impairment. The dose which causes a 50% probability of visual impairment is approximately 15 Gy. 10 refs., 4 figs., 1 tab

Stretchable Binary Fresnel Lens for Focus Tuning

NARCIS (Netherlands)

Li, X.; Wei, L.; Poelma, R.H.; Vollebregt, S.; Wei, J.; Urbach, Paul; Sarro, P.M.; Zhang, G.Q.

2016-01-01

This paper presents a tuneable binary amplitude Fresnel lens produced by wafer-level microfabrication. The Fresnel lens is fabricated by encapsulating lithographically defined vertically aligned carbon nanotube (CNT) bundles inside a polydimethyl-siloxane (PDMS) layer. The composite lens material

Activation of neuronal nitric oxide synthase in cerebellum of chronic hepatic encephalopathy rats is associated with up-regulation of NADPH-producing pathway.

Science.gov (United States)

Singh, Santosh; Trigun, Surendra K

2010-09-01

Cerebellum-associated functions get affected during mild hepatic encephalopathy (MHE) in patients with chronic liver failure (CLF). Involvement of nitrosative and antioxidant factors in the pathogenesis of chronic hepatic encephalopathy is an evolving concept and needs to be defined in a true CLF animal model. This article describes profiles of NADPH-dependent neuronal nitric oxide synthase (nNOS) and those of glutathione peroxidase and glutathione reductase (GR) vis-a-vis regulation of NADPH-producing pathway in the cerebellum of CLF rats induced by administration of thioacetamide (100 mg kg⁻¹ b.w., i.p.) up to 10 days and confirming MHE on Morris water maze tests. Significant increases in the expression of nNOS protein and nitric oxide (NOx) level coincided with a similar increment in NADPH-diaphorase activity in the cerebellum of CLF rats. Glutathione peroxidase and GR utilize NADPH to regenerate reduced glutathione (GSH) in the cells. Both these enzymes and GSH level were found to be static and thus suggested efficient turnover of GSH in the cerebellum of MHE rats. Relative levels of glucose-6-phosphate dehydrogenase (G6PD) vs. phosphofructokinase 2 (PFK2) determine the rate of pentose phosphate pathway (PPP) responsible to synthesize NADPH. The cerebellum of CLF rats showed overactivation of G6PD with a significant decline in the expression of PFK2 and thus suggested activation of PPP in the cerebellum during MHE. It is concluded that concordant activations of PPP and nNOS in cerebellum of MHE rats could be associated with the implication of NOx in the pathogenesis of MHE.

21 CFR 886.1390 - Flexible diagnostic Fresnel lens.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Flexible diagnostic Fresnel lens. 886.1390 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1390 Flexible diagnostic Fresnel lens. (a) Identification. A flexible diagnostic Fresnel lens is a device that is a very thin lens which has...

A catoptric lens

International Nuclear Information System (INIS)

Rambauske, W.R.

1973-01-01

The invention relates to a catoptric lens for combining energies transmitted by several sources such as lasers; said lens comprising mirrors, the reflective surfaces of which have their focuses spaced from a common axis of symmetry. By means of these reflecting surfaces, which are generated by the nutation of portions of quadratic conics about the axis of symmetry, it is possible to focus the energy emmited by several lasers at the focus of the exit-mirror reflecting surface. This can be applied to thermonuclear fusion [fr

Structural rearrangements occurring upon cofactor binding in the Mycobacterium smegmatis β-ketoacyl-acyl carrier protein reductase MabA.

Science.gov (United States)

Küssau, Tanja; Flipo, Marion; Van Wyk, Niel; Viljoen, Albertus; Olieric, Vincent; Kremer, Laurent; Blaise, Mickaël

2018-05-01

In mycobacteria, the ketoacyl-acyl carrier protein (ACP) reductase MabA (designated FabG in other bacteria) catalyzes the NADPH-dependent reduction of β-ketoacyl-ACP substrates to β-hydroxyacyl-ACP products. This first reductive step in the fatty-acid biosynthesis elongation cycle is essential for bacteria, which makes MabA/FabG an interesting drug target. To date, however, very few molecules targeting FabG have been discovered and MabA remains the only enzyme of the mycobacterial type II fatty-acid synthase that lacks specific inhibitors. Despite the existence of several MabA/FabG crystal structures, the structural rearrangement that occurs upon cofactor binding is still not fully understood. Therefore, unlocking this knowledge gap could help in the design of new inhibitors. Here, high-resolution crystal structures of MabA from Mycobacterium smegmatis in its apo, NADP + -bound and NADPH-bound forms are reported. Comparison of these crystal structures reveals the structural reorganization of the lid region covering the active site of the enzyme. The crystal structure of the apo form revealed numerous residues that trigger steric hindrance to the binding of NADPH and substrate. Upon NADPH binding, these residues are pushed away from the active site, allowing the enzyme to adopt an open conformation. The transition from an NADPH-bound to an NADP + -bound form is likely to facilitate release of the product. These results may be useful for subsequent rational drug design and/or for in silico drug-screening approaches targeting MabA/FabG.

Oleic, Linoleic and Linolenic Acids Increase ROS Production by Fibroblasts via NADPH Oxidase Activation

Science.gov (United States)

Hatanaka, Elaine; Dermargos, Alexandre; Hirata, Aparecida Emiko; Vinolo, Marco Aurélio Ramirez; Carpinelli, Angelo Rafael; Newsholme, Philip; Armelin, Hugo Aguirre; Curi, Rui

2013-01-01

The effect of oleic, linoleic and γ-linolenic acids on ROS production by 3T3 Swiss and Rat 1 fibroblasts was investigated. Using lucigenin-amplified chemiluminescence, a dose-dependent increase in extracellular superoxide levels was observed during the treatment of fibroblasts with oleic, linoleic and γ-linolenic acids. ROS production was dependent on the addition of β-NADH or NADPH to the medium. Diphenyleneiodonium inhibited the effect of oleic, linoleic and γ-linolenic acids on fibroblast superoxide release by 79%, 92% and 82%, respectively. Increased levels of p47phox phosphorylation due to fatty acid treatment were detected by Western blotting analyses of fibroblast proteins. Increased p47phox mRNA expression was observed using real-time PCR. The rank order for the fatty acid stimulation of the fibroblast oxidative burst was as follows: γ-linolenic > linoleic > oleic. In conclusion, oleic, linoleic and γ-linolenic acids stimulated ROS production via activation of the NADPH oxidase enzyme complex in fibroblasts. PMID:23579616

Oleic, linoleic and linolenic acids increase ros production by fibroblasts via NADPH oxidase activation.

Directory of Open Access Journals (Sweden)

Elaine Hatanaka

Full Text Available The effect of oleic, linoleic and γ-linolenic acids on ROS production by 3T3 Swiss and Rat 1 fibroblasts was investigated. Using lucigenin-amplified chemiluminescence, a dose-dependent increase in extracellular superoxide levels was observed during the treatment of fibroblasts with oleic, linoleic and γ-linolenic acids. ROS production was dependent on the addition of β-NADH or NADPH to the medium. Diphenyleneiodonium inhibited the effect of oleic, linoleic and γ-linolenic acids on fibroblast superoxide release by 79%, 92% and 82%, respectively. Increased levels of p47 (phox phosphorylation due to fatty acid treatment were detected by Western blotting analyses of fibroblast proteins. Increased p47 (phox mRNA expression was observed using real-time PCR. The rank order for the fatty acid stimulation of the fibroblast oxidative burst was as follows: γ-linolenic > linoleic > oleic. In conclusion, oleic, linoleic and γ-linolenic acids stimulated ROS production via activation of the NADPH oxidase enzyme complex in fibroblasts.

21 CFR 886.1395 - Diagnostic Hruby fundus lens.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Diagnostic Hruby fundus lens. 886.1395 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1395 Diagnostic Hruby fundus lens. (a) Identification. A diagnostic Hruby fundus lens is a device that is a 55 diopter lens intended for use in the...

Influence of dietary zinc on convulsive seizures and hippocampal NADPH diaphorase-positive neurons in seizure susceptible EL mouse.

Science.gov (United States)

Nagatomo, I; Akasaki, Y; Uchida, M; Kuchiiwa, S; Nakagawa, S; Takigawa, M

1998-04-13

Adequate, high and deficient dietary levels of zinc (Zn) were compared in seizure-susceptible EL mice with respect to convulsions and to nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase-positive hippocampal neurons. Diaphorase positivity is associated with nitric oxide (NO) production. Convulsive seizures in the EL mice given the various diets did not differ over 1-4 weeks, but convulsions in EL mice given the Zn-deficient diet for 4 weeks were more effectively suppressed by injection of zonisamide (ZNS) (75 mg/kg intraperitoneally) than in mice receiving high- or adequate-Zn diet for the same period. Numbers of NADPH diaphorase-positive neurons in the CA1/CA2 region of the hippocampal formation were significantly higher in mice given the Zn-deficient diet for 4 weeks than in mice fed adequate Zn. Mice receiving the high-Zn diet for the same period had significantly fewer NADPH diaphorase-positive neurons in the subiculum than mice with adequate Zn. These results suggest that Zn deficiency inhibits convulsive seizures of EL mice, and that dietary Zn influences numbers of NO producing neurons in the hippocampal formation. Copyright 1998 Elsevier Science B.V.

The Role of Aquaporins in Ocular Lens Homeostasis

Science.gov (United States)

Schey, Kevin L.; Petrova, Rosica S.; Gletten, Romell B.; Donaldson, Paul J.

2017-01-01

Aquaporins (AQPs), by playing essential roles in the maintenance of ocular lens homeostasis, contribute to the establishment and maintenance of the overall optical properties of the lens over many decades of life. Three aquaporins, AQP0, AQP1 and AQP5, each with distinctly different functional properties, are abundantly and differentially expressed in the different regions of the ocular lens. Furthermore, the diversity of AQP functionality is increased in the absence of protein turnover by age-related modifications to lens AQPs that are proposed to alter AQP function in the different regions of the lens. These regional differences in AQP functionality are proposed to contribute to the generation and directionality of the lens internal microcirculation; a system of circulating ionic and fluid fluxes that delivers nutrients to and removes wastes from the lens faster than could be achieved by passive diffusion alone. In this review, we present how regional differences in lens AQP isoforms potentially contribute to this microcirculation system by highlighting current areas of investigation and emphasizing areas where future work is required. PMID:29231874

21 CFR 886.1380 - Diagnostic condensing lens.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Diagnostic condensing lens. 886.1380 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1380 Diagnostic condensing lens. (a) Identification. A diagnostic condensing lens is a device used in binocular indirect ophthalmoscopy (a procedure...

Rac1-NADPH oxidase signaling promotes CD36 activation under glucotoxic conditions in pancreatic beta cells.

Science.gov (United States)

Elumalai, Suma; Karunakaran, Udayakumar; Lee, In Kyu; Moon, Jun Sung; Won, Kyu Chang

2017-04-01

We recently reported that cluster determinant 36 (CD36), a fatty acid transporter, plays a pivotal role in glucotoxicity-induced β-cell dysfunction. However, little is known about how glucotoxicity influences CD36 expression. Emerging evidence suggests that the small GTPase Rac1 is involved in the pathogenesis of beta cell dysfunction in type 2 diabetes (T2D). The primary objective of the current study was to determine the role of Rac1 in CD36 activation and its impact on β-cell dysfunction in diabetes mellitus. To address this question, we subjected INS-1 cells and human beta cells (1.1B4) to high glucose conditions (30mM) in the presence or absence of Rac1 inhibition either by NSC23766 (Rac1 GTPase inhibitor) or small interfering RNA. High glucose exposure in INS-1 and human beta cells (1.1b4) resulted in the activation of Rac1 and induced cell apoptosis. Rac1 activation mediates NADPH oxidase (NOX) activation leading to elevated ROS production in both cells. Activation of the Rac1-NOX complex by high glucose levels enhanced CD36 expression in INS-1 and human 1.1b4 beta cell membrane fractions. The inhibition of Rac1 by NSC23766 inhibited NADPH oxidase activity and ROS generation induced by high glucose concentrations in INS-1 & human 1.1b4 beta cells. Inhibition of Rac1-NOX complex activation by NSC23766 significantly reduced CD36 expression in INS-1 and human 1.1b4 beta cell membrane fractions. In addition, Rac1 inhibition by NSC23766 significantly reduced high glucose-induced mitochondrial dysfunction. Furthermore, NADPH oxidase inhibition by VAS2870 also attenuated high glucose-induced ROS generation and cell apoptosis. These results suggest that Rac1-NADPH oxidase dependent CD36 expression contributes to high glucose-induced beta cell dysfunction and cell death. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Bacterial transmission from lens storage cases to contact lenses-Effects of lens care solutions and silver impregnation of cases.

Science.gov (United States)

Vermeltfoort, Pit B J; Hooymans, Johanna M M; Busscher, Henk J; van der Mei, Henny C

2008-10-01

The killing efficacies of multipurpose lens care solutions on planktonic and biofilm bacteria grown in polypropylene contact lens storage cases with and without silver impregnation and effects on bacterial transmission from storage cases to silicone hydrogel contact lenses were investigated. For transmission studies, biofilms of Staphylococcus aureus 835 or Pseudomonas aeruginosa no. 3 were grown on lens storage cases and incubated with a contact lens in different multipurpose lens care solutions (Opti-Free(R)Express(R), ReNu(R) MultiPlus(R), and SoloCare Aquatrade mark) or 0.9% NaCl. In addition, planktonic bacteria were directly suspended in multipurpose solutions and their killing efficacies were determined. The numbers of transmitted live and dead bacteria on the lenses were measured using a combination of plate counting and fluorescence microscopy. The highest killing efficacies were shown by Opti-Free(R) Express(R) for planktonic as well as for biofilm bacteria. Silver impregnation of lens cases in combination with the prescribed solution increased the killing efficacy for P. aeruginosa in biofilms, whereas effects for S. aureus were minor. Lowest numbers of live and dead bacteria were transmitted to a lens in Opti-Free(R) Express(R) multipurpose solution, with no significant differences between lens types and no effects of silver impregnation. (c) 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2008. (c) 2008 Wiley Periodicals, Inc.

Iris reconstruction combined with iris-claw intraocular lens implantation for the management of iris-lens injured patients.

Science.gov (United States)

Hu, Shufang; Wang, Mingling; Xiao, Tianlin; Zhao, Zhenquan

2016-03-01

To study the efficiency and safety of iris reconstruction combined with iris-claw intraocular lens (IOL) implantation in the patients with iris-lens injuries. Retrospective, noncomparable consecutive case series study. Eleven patients (11 eyes) following iris-lens injuries underwent iris reconstructions combined with iris-claw IOL implantations. Clinical data, such as cause and time of injury, visual acuity (VA), iris and lens injuries, surgical intervention, follow-up period, corneal endothelial cell count, and optical coherence tomography, were collected. Uncorrected VA (UCVA) in all injured eyes before combined surgery was equal to or iris returned to its natural round shape or smaller pupil, and the iris-claw IOLs in the 11 eyes were well-positioned on the anterior surface of reconstructed iris. No complications occurred in those patients. Iris reconstruction combined with iris-claw IOL implantation is a safe and efficient procedure for an eye with iris-lens injury in the absence of capsular support.

Circuit lower bounds in bounded arithmetics

Czech Academy of Sciences Publication Activity Database

Pich, Ján

2015-01-01

Roč. 166, č. 1 (2015), s. 29-45 ISSN 0168-0072 R&D Projects: GA AV ČR IAA100190902 Keywords : bounded arithmetic * circuit lower bounds Subject RIV: BA - General Mathematics Impact factor: 0.582, year: 2015 http://www.sciencedirect.com/science/article/pii/S0168007214000888

Wide-range tunable magnetic lens for tabletop electron microscope

International Nuclear Information System (INIS)

Chang, Wei-Yu; Chen, Fu-Rong

2016-01-01

A tabletop scanning electron microscope (SEM) utilizes permanent magnets as condenser lenses to minimize its size, but this sacrifices the tunability of condenser lenses such that a tabletop system can only be operated with a fixed accelerating voltage. In contrast, the traditional condenser lens utilizes an electromagnetic coil to adjust the optical properties, but the size of the electromagnetic lens is inevitably larger. Here, we propose a tunable condenser lens for a tabletop SEM that uses a combination of permanent magnets and electromagnetic coils. The overall dimensions of the newly designed lens are the same as the original permanent magnet lens, but the new lens allows the tabletop SEM to be operated at different accelerating voltages between 1 kV and 15 kV. - Highlights: • A compact condenser lens combines both permanent magnet and coils. • A tunable lens is designed to keep the same focal point for voltage 1 to 15 kV. • A miniature tunable lens which can directly fit into tabletop SEM.

Wide-range tunable magnetic lens for tabletop electron microscope

Energy Technology Data Exchange (ETDEWEB)

Chang, Wei-Yu; Chen, Fu-Rong, E-mail: fchen1@me.com

2016-12-15

A tabletop scanning electron microscope (SEM) utilizes permanent magnets as condenser lenses to minimize its size, but this sacrifices the tunability of condenser lenses such that a tabletop system can only be operated with a fixed accelerating voltage. In contrast, the traditional condenser lens utilizes an electromagnetic coil to adjust the optical properties, but the size of the electromagnetic lens is inevitably larger. Here, we propose a tunable condenser lens for a tabletop SEM that uses a combination of permanent magnets and electromagnetic coils. The overall dimensions of the newly designed lens are the same as the original permanent magnet lens, but the new lens allows the tabletop SEM to be operated at different accelerating voltages between 1 kV and 15 kV. - Highlights: • A compact condenser lens combines both permanent magnet and coils. • A tunable lens is designed to keep the same focal point for voltage 1 to 15 kV. • A miniature tunable lens which can directly fit into tabletop SEM.

Use of NAD(P)H fluorescence measurement for on-line monitoring of metabolic state of Azohydromonas australica in poly(3-hydroxybutyrate) production.

Science.gov (United States)

Gahlawat, Geeta; Srivastava, Ashok K

2013-02-01

Culture fluorescence measurement is an indirect and non-invasive method of biomass estimation to assess the metabolic state of the microorganism in a fermentation process. In the present investigation, NAD(P)H fluorescence has been used for on-line in situ characterization of metabolic changes occurring during different phases of batch cultivation of Azohydromonas australica in growth associated poly(3-hydroxybutyrate) or PHB production. A linear correlation between biomass concentration and net NAD(P)H fluorescence was obtained during early log phase (3-12 h) and late log phase (24-39 h) of PHB fermentation. After 12 h (mid log phase) cultivation PHB accumulation shot up and a drop in culture fluorescence was observed which synchronously exhibited continuous utilization of NAD(P)H for the synthesis of biomass and PHB formation simultaneously. A decrease in the observed net fluorescence value was observed again towards the end of fermentation (at 39 h) which corresponded very well with the culture starvation and substrate depletion towards the end of cultivation inside the bioreactor. It was therefore concluded that NAD(P)H fluorescence measurements could be used for indication of the time of fresh nutrient (substrate) feed during substrate limitation to further enhance the PHB production.

RhoA/ROCK downregulates FPR2-mediated NADPH oxidase activation in mouse bone marrow granulocytes.

Science.gov (United States)

Filina, Julia V; Gabdoulkhakova, Aida G; Safronova, Valentina G

2014-10-01

Polymorphonuclear neutrophils (PMNs) express the high and low affinity receptors to formylated peptides (mFPR1 and mFPR2 in mice, accordingly). RhoA/ROCK (Rho activated kinase) pathway is crucial for cell motility and oxidase activity regulated via FPRs. There are contradictory data on RhoA-mediated regulation of NADPH oxidase activity in phagocytes. We have shown divergent Rho GTPases signaling via mFPR1 and mFPR2 to NADPH oxidase in PMNs from inflammatory site. The present study was aimed to find out the role of RhoA/ROCK in the respiratory burst activated via mFPR1 and mFPR2 in the bone marrow PMNs. Different kinetics of RhoA activation were detected with 0.1μM fMLF and 1μM WKYMVM operating via mFPR1 and mFPR2, accordingly. RhoA was translocated in fMLF-activated cells towards the cell center and juxtamembrane space versus uniform allocation in the resting cells. Specific inhibition of RhoA by CT04, Rho inhibitor I, weakly depressed the respiratory burst induced via mFPR1, but significantly increased the one induced via mFPR2. Inhibition of ROCK, the main effector of RhoA, by Y27632 led to the same effect on the respiratory burst. Regulation of mFPR2-induced respiratory response by ROCK was impossible under the cytoskeleton disruption by cytochalasin D, whereas it persisted in the case of mFPR1 activation. Thus we suggest RhoA to be one of the regulatory and signal transduction components in the respiratory burst through FPRs in the mouse bone marrow PMNs. Both mFPR1 and mFPR2 binding with a ligand trigger the activation of RhoA. FPR1 signaling through RhoA/ROCK increases NADPH-oxidase activity. But in FPR2 action RhoA/ROCK together with cytoskeleton-linked systems down-regulates NADPH-oxidase. This mechanism could restrain the reactive oxygen species dependent damage of own tissues during the chemotaxis of PMNs and in the resting cells. Copyright © 2014 Elsevier Inc. All rights reserved.

Activation of endothelial cells after exposure to ambient ultrafine particles: The role of NADPH oxidase

International Nuclear Information System (INIS)

Mo Yiqun; Wan Rong; Chien Sufan; Tollerud, David J.; Zhang Qunwei

2009-01-01

Several studies have shown that ultrafine particles (UFPs) may pass from the lungs to the circulation because of their very small diameter, and induce lung oxidative stress with a resultant increase in lung epithelial permeability. The direct effects of UFPs on vascular endothelium remain unknown. We hypothesized that exposure to UFPs leads to endothelial cell O 2 ·- generation via NADPH oxidase and results in activation of endothelial cells. Our results showed that UFPs, at a non-toxic dose, induced reactive oxygen species (ROS) generation in mouse pulmonary microvascular endothelial cells (MPMVEC) that was inhibited by pre-treatment with the ROS scavengers or inhibitors, but not with the mitochondrial inhibitor, rotenone. UFP-induced ROS generation in MPMVEC was abolished by p67 phox siRNA transfection and UFPs did not cause ROS generation in MPMVEC isolated from gp91 phox knock-out mice. UFP-induced ROS generation in endothelial cells was also determined in vivo by using a perfused lung model with imaging. Moreover, Western blot and immunofluorescence staining results showed that MPMVEC treated with UFPs resulted in the translocation of cytosolic proteins of NADPH oxidase, p47 phox , p67 phox and rac 1, to the plasma membrane. These results demonstrate that NADPH oxidase in the pulmonary endothelium is involved in ROS generation following exposure to UFPs. To investigate the activation of endothelial cells by UFP-induced oxidative stress, we determined the activation of the mitogen-activated protein kinases (MAPKs) in MPMVEC. Our results showed that exposure of MPMVEC to UFPs caused increased phosphorylation of p38 and ERK1/2 MAPKs that was blocked by pre-treatment with DPI or p67 phox siRNA. Exposure of MPMVEC obtained from gp91 phox knock-out mice to UFPs did not cause increased phosphorylation of p38 and ERK1/2 MAPKs. These findings confirm that UFPs can cause endothelial cells to generate ROS directly via activation of NADPH oxidase. UFP-induced ROS lead to

21 CFR 886.1420 - Ophthalmic lens gauge.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic lens gauge. 886.1420 Section 886.1420...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1420 Ophthalmic lens gauge. (a) Identification. An ophthalmic lens gauge is a calibrated device intended to manually measure the curvature of a...

Crystal Structure of Perakine Reductase, Founding Member of a Novel Aldo-Keto Reductase (AKR) Subfamily That Undergoes Unique Conformational Changes during NADPH Binding*

Science.gov (United States)

Sun, Lianli; Chen, Yixin; Rajendran, Chitra; Mueller, Uwe; Panjikar, Santosh; Wang, Meitian; Mindnich, Rebekka; Rosenthal, Cindy; Penning, Trevor M.; Stöckigt, Joachim

2012-01-01

Perakine reductase (PR) catalyzes the NADPH-dependent reduction of the aldehyde perakine to yield the alcohol raucaffrinoline in the biosynthetic pathway of ajmaline in Rauvolfia, a key step in indole alkaloid biosynthesis. Sequence alignment shows that PR is the founder of the new AKR13D subfamily and is designated AKR13D1. The x-ray structure of methylated His6-PR was solved to 2.31 Å. However, the active site of PR was blocked by the connected parts of the neighbor symmetric molecule in the crystal. To break the interactions and obtain the enzyme-ligand complexes, the A213W mutant was generated. The atomic structure of His6-PR-A213W complex with NADPH was determined at 1.77 Å. Overall, PR folds in an unusual α8/β6 barrel that has not been observed in any other AKR protein to date. NADPH binds in an extended pocket, but the nicotinamide riboside moiety is disordered. Upon NADPH binding, dramatic conformational changes and movements were observed: two additional β-strands in the C terminus become ordered to form one α-helix, and a movement of up to 24 Å occurs. This conformational change creates a large space that allows the binding of substrates of variable size for PR and enhances the enzyme activity; as a result cooperative kinetics are observed as NADPH is varied. As the founding member of the new AKR13D subfamily, PR also provides a structural template and model of cofactor binding for the AKR13 family. PMID:22334702

NADPH oxidase and redox status in amygdala, hippocampus and cortex of male Wistar rats in an animal model of post-traumatic stress disorder.

Science.gov (United States)

Petrovic, Romana; Puskas, Laslo; Jevtic Dozudic, Gordana; Stojkovic, Tihomir; Velimirovic, Milica; Nikolic, Tatjana; Zivkovic, Milica; Djorovic, Djordje J; Nenadovic, Milutin; Petronijevic, Natasa

2018-05-26

Post-traumatic stress disorder (PTSD) is a highly prevalent and impairing disorder. Oxidative stress is implicated in its pathogenesis. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is an important source of free radicals. The aim of the study was to assess oxidative stress parameters, activities of respiratory chain enzymes, and the expression of NADPH oxidase subunits (gp91phox, p22phox, and p67phox) in the single prolonged stress (SPS) animal model of PTSD. Twenty-four (12 controls; 12 subjected to SPS), 9-week-old, male Wistar rats were used. SPS included physical restraint, forced swimming, and ether exposure. The rats were euthanized seven days later. Cortex, hippocampus, amygdala, and thalamus were dissected. Malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), Complex I, and cytochrome C oxidase were measured using spectrophotometric methods, while the expression of NADPH oxidase subunits was determined by Western blot. Increased MDA and decreased GSH concentrations were found in the amygdala and hippocampus of the SPS rats. SOD activity was decreased in amygdala and GPx was decreased in hippocampus. Increased expression of the NADPH oxidase subunits was seen in amygdala, while mitochondrial respiratory chain enzyme expression was unchanged both in amygdala and hippocampus. In the cortex concentrations of MDA and GSH were unchanged despite increased Complex I and decreased GPx, while in the thalamus no change of any parameter was noticed. We conclude that oxidative stress is present in hippocampus and amygdala seven days after the SPS procedure. NADPH oxidase seems to be a main source of free radicals in the amygdala.

Adaptive mechanical-wetting lens actuated by ferrofluids

Science.gov (United States)

Cheng, Hui-Chuan; Xu, Su; Liu, Yifan; Levi, Shoshana; Wu, Shin-Tson

2011-04-01

We report an adaptive mechanical-wetting lens actuated by ferrofluids. The ferrofluids works like a piston to pump liquids in and out from the lens chamber, which in turn reshapes the lens curvature and changes the focal length. Both positive and negative lenses are demonstrated experimentally. The ferrofluid-actuated mechanical-wetting lens exhibits some attractive features, such as high resolution, fast response time, low power consumption, simple structure and electronic control, weak gravity effect, and low cost. Its potential applications in medical imaging, surveillance, and commercial electronics are foreseeable.

Numerical studies on the ramped density plasma lens

International Nuclear Information System (INIS)

Williams, R.L.; Katsouleas, T.

1992-01-01

We consider the so-called adiabatic plasma lens when the plasma density is ramped too quickly to be considered adiabatic. The lens length can be much shorter in such a case, but the final spot size is shown to be larger by a factor of √1+α 2 than for a slowly ramped plasma lens with the same initial and final density (where α=-β'/2 is proportional to the plasma density gradient). We find that the final spot size is the same whether or not the Courant-Snyder parameters of the beam (α and β) are matched to the lens. However, matched beams allow the plasma density to be lower while unmatched beams allow the lens to be shorter (for the same α and for the same final to initial plasma density ratio). Finally, we find that a smaller spot size can be obtained for a given lens length and density ratio by starting at smaller α and increasing α along the lens

LASL lens design procedure: simple, fast, precise, versatile

International Nuclear Information System (INIS)

Brixner, B.

1978-11-01

The Los Alamos Scientific Laboratory general-purpose lens design procedure optimizes specific lens prescriptions to obtain the smallest possible image spots and therefore near-spherical wave fronts of light converging on all images in the field of view. Optical image errors are analyzed in much the same way that they are measured on the optical bench. This lens design method is made possible by using the full capabilities of large electronic computers. First, the performance of the whole lens is sampled with many precisely traced skew rays. Next, lens performance is analyzed with spot diagrams generated by the many rays. Third, lens performance is optimized with a least squares system aimed at reducing all image errors to zero. This statistical approach to lens design uses skew rays and precisely measured ray deviations from ideal image points to achieve greater accuracy than was possible with the classical procedure, which is based on approximate expressions derived from simplified ray traces developed for pencil-and-paper calculations

The Role of Mitochondrial NADPH-Dependent Isocitrate Dehydrogenase in Cancer Cells

Directory of Open Access Journals (Sweden)

Katarína Smolková

2012-01-01

Full Text Available Isocitrate dehydrogenase 2 (IDH2 is located in the mitochondrial matrix. IDH2 acts in the forward Krebs cycle as an NADP+-consuming enzyme, providing NADPH for maintenance of the reduced glutathione and peroxiredoxin systems and for self-maintenance by reactivation of cystine-inactivated IDH2 by glutaredoxin 2. In highly respiring cells, the resulting NAD+ accumulation then induces sirtuin-3-mediated activating IDH2 deacetylation, thus increasing its protective function. Reductive carboxylation of 2-oxoglutarate by IDH2 (in the reverse Krebs cycle direction, which consumes NADPH, may follow glutaminolysis of glutamine to 2-oxoglutarate in cancer cells. When the reverse aconitase reaction and citrate efflux are added, this overall “anoxic” glutaminolysis mode may help highly malignant tumors survive aglycemia during hypoxia. Intermittent glycolysis would hypothetically be required to provide ATP. When oxidative phosphorylation is dormant, this mode causes substantial oxidative stress. Arg172 mutants of human IDH2—frequently found with similar mutants of cytosolic IDH1 in grade 2 and 3 gliomas, secondary glioblastomas, and acute myeloid leukemia—catalyze reductive carboxylation of 2-oxoglutarate and reduction to D-2-hydroxyglutarate, which strengthens the neoplastic phenotype by competitive inhibition of histone demethylation and 5-methylcytosine hydroxylation, leading to genome-wide histone and DNA methylation alternations. D-2-hydroxyglutarate also interferes with proline hydroxylation and thus may stabilize hypoxia-induced factor α.

High Dk piggyback contact lens system for contact lens-intolerant keratoconus patients.

Science.gov (United States)

Sengor, Tomris; Kurna, Sevda Aydin; Aki, Suat; Ozkurt, Yelda

2011-01-01

The aim of the study was to examine the clinical success of high Dk (oxygen permeability) piggyback contact lens (PBCL) systems for the correction of contact lens intolerant keratoconus patients. Sixteen patients (29 eyes) who were not able to wear gas-permeable rigid lenses were included in this study. Hyper Dk silicone hydrogel (oxygen transmissibility or Dk/t = 150 units) and fluorosilicone methacrylate copolymer (Dk/t = 100 units) lenses were chosen as the PBCL systems. The clinical examinations included visual acuity and corneal observation by biomicroscopy, keratometer reading, and fluorescein staining before and after fitting the PBCL system. INDICATIONS FOR USING PBCL SYSTEM WERE: lens stabilization and comfort, improving comfort, and adding protection to the cone. Visual acuities increased significantly in all of the patients compared with spectacles (P = 0). Improvement in visual acuity compared with rigid lenses alone was recorded in 89.7% of eyes and no alteration of the visual acuity was observed in 10.3% of the eyes. Wearing time of PBCL systems for most of the patients was limited time (mean 6 months, range 3-12 months); thereafter they tolerated rigid lenses alone except for 2 patients. The PBCL system is a safe and effective method to provide centering and corneal protection against mechanical trauma by the rigid lenses for keratoconus patients and may increase contact lens tolerance.

Development of Powerhouse Using Fresnel lens

Directory of Open Access Journals (Sweden)

Al-Dohani Nawar Saif

2018-01-01

Full Text Available Solar energy is an alternative source of renewable energy. Sultanate of Oman government showed initiation on utilization of solar energy for domestic and industrial applications. Fresnel lens is one of the methods to collect maximum energy by gathering heat of the sun in the concentrated form (using solar collectors. Earlier research work discloses that Fresnel lens gave better result in terms of power output and produces lower heat loss as compared to linear –parabolic solar collectors. In this work, development of a proto Fresnel lens power house was made to generate electricity. The focused heat from Fresnel lens was used to heat the molten salt in a heat exchanger to produce the steam. The generated steam was used to rotate the steam engine coupled to a generator. In the current work, a maximum power of 30 W was produced. In addition, comparative study was carried out regarding solar salts and heat exchanger materials to understand the Fresnel powerhouse performance. Overall the present study gave valuable information regarding usage of Fresnel lens for electricity generation in Oman.

Orbiting objective lens telescope system and method

International Nuclear Information System (INIS)

Crooks, J.W. Jr.

1984-01-01

A large objective lens is placed in a highly eccentric orbit about the earth. The orbit and orientation of the lens are carefully chosen so that it focuses light or other radiation from a preselected astronomical object into an image which slowly moves across the surface of the earth. A row of optical sensing units is located on the surface of the earth so that the image focused by the orbiting objective lens will travel substantially perpendicularly across the row during an observation. Output data generated from the sensing units may be multiplexed and fed to a real time processor which produces display signals. Each of the sensing units provides one scan line of the image being observed. The display signals are fed to a suitable display device which produces a picture of the preselected astronomical object. The objective lens may comprise a large flexible Fresnel zone plate or a flexible convex lens carried by a bicycle wheel-type supporting structure. The lens and supporting structure may be unfolded from compact cargo configurations and rotated after being placed into orbit

Transient anterior subcapsular vacuolar change of the crystalline lens in patients after posterior chamber phakic intraocular lens implantation.

Science.gov (United States)

Chung, Jin Kwon; Shin, Jin Hee; Lee, Sung Jin

2013-10-25

We present two cases of transient vacuolar changes in the anterior subcapsular space of the crystalline lens in patients after posterior chamber phakic intraocular lens implantation. Implantable collamer lenses (ICL) were implanted in healthy myopic patients. Vacuolar changes developed just after the irrigating procedure through the narrow space between the ICL and the crystalline lens. Slit-lamp examinations and spectral domain optical coherence tomography showed bleb-like lesions in the anterior subcapsular space of one eye in each case, though the lesions gradually improved without visual deterioration. Consequently, the lesions turned into a few anterior subcapsular small faint opacities. Direct irrigation of the narrow space confined by the ICL and the crystalline lens is at risk for the development of vacuolar changes in the crystalline lens. The observed spontaneous reversal indicates that surgeons should not rush to surgical intervention but rather opt for close follow over several weeks.

Rat silicone hydrogel contact lens model: effects of high- versus low-Dk lens wear.

Science.gov (United States)

Zhang, Yunfan; Gabriel, Manal M; Mowrey-McKee, Mary F; Barrett, Ronald P; McClellan, Sharon; Hazlett, Linda D

2008-11-01

This study used a rat contact lens (CL) model to test if high- versus low-Dk lens wear caused changes in (1) conjunctival Langerhans cell (LC) number or location; (2) Bcl-2 expression; and (3) infection risk. Female, Lewis rats wore a high- or low-Dk CL continuously for 2 weeks. Afterward, corneas were harvested and processed for ADPase activity to identify LCs, for immunostaining and for real time-polymerase chain reaction. Contact lens-wearing rats also were challenged with Pseudomonas aeruginosa by placing a bacterial-soaked CL on the eye followed by topical delivery of bacteria. After 48 hrs, slit lamp examination and real time-polymerase chain reaction were used to evaluate the corneal response. Conjunctival LC were significantly increased after low- versus high-Dk CL wear (PDk lens wearing group. Bcl-2 mRNA levels were significantly decreased in low- versus high-Dk CL wearing rats, while Bax, FasL, caspase 3, and caspase 9 levels were unchanged. Immunostaining for Bcl-2 showed fewer positively stained epithelial cells in the low- versus high-Dk lens wearing group. After bacterial challenge, 30% of low- versus none of the high-Dk CL wearing corneas became infected and showed increased mRNA levels for several proinflammatory cytokines/chemokines, inducible nitric oxide synthase and matrix metalloproteinase-9. Low- versus high-Dk or non-CL wear led to an increased number of conjunctival LC, decreased Bcl-2 levels, and increased the risk of bacterial infection.

Properties of the cathode lens combined with a focusing magnetic/immersion-magnetic lens

Czech Academy of Sciences Publication Activity Database

Konvalina, Ivo; Müllerová, Ilona

2011-01-01

Roč. 645, č. 1 (2011), s. 55-59 ISSN 0168-9002 R&D Projects: GA ČR GAP102/10/1410; GA AV ČR IAA100650902; GA MŠk ED0017/01/01 Institutional research plan: CEZ:AV0Z20650511 Keywords : cathode lens * compound objective lens * aberration coefficients * spot size * field calculations Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.207, year: 2011

Joint Functions of Protein Residues and NADP(H) in Oxygen Activation by Flavin-containing Monooxygenase

NARCIS (Netherlands)

Orru, Roberto; Torres Pazmino, Daniel; Fraaije, Marco W.; Mattevi, Andrea

2010-01-01

The reactivity of flavoenzymes with dioxygen is at the heart of a number of biochemical reactions with far reaching implications for cell physiology and pathology. Flavin-containing monooxygenases are an attractive model system to study flavin-mediated oxygenation. In these enzymes, the NADP(H)

Peroxisomal Polyamine Oxidase and NADPH-Oxidase cross-talk for ROS homeostasis which affects respiration rate in Arabidopsis thaliana

Directory of Open Access Journals (Sweden)

Efthimios A. Andronis

2014-04-01

Full Text Available Homeostasis of reactive oxygen species (ROS in the intracellular compartments is of critical importance as ROS have been linked with nearly all cellular processes and more importantly with diseases and aging. PAs are nitrogenous molecules with an evolutionary conserved role in the regulation of metabolic and energetic status of cells. Recent evidence also suggests that polyamines (PA are major regulators of ROS homeostasis. In Arabidopsis the backconversion of the PAs spermidine (Spd and spermine (Spm to putrescine (Put and Spd, respectively is catalyzed by two peroxisomal PA oxidases (AtPAO. However, the physiological role of this pathway remains largely elusive. Here we explore the role of peroxisomal PA backconversion and in particular that catalyzed by the highly expressed AtPAO3 in the regulation of ROS homeostasis and mitochondrial respiratory burst. Exogenous PAs exert an NADPH-oxidase dependent stimulation of oxygen consumption, with Spd exerting the strongest effect. This increase is attenuated by treatment with the NADPH-oxidase blocker diphenyleneiodonium iodide (DPI. Loss-of-function of AtPAO3 gene results to increased NADPH-oxidase-dependent production of superoxide anions (O2.-, but not H2O2, which activate the mitochondrial alternative oxidase pathway (AOX. On the contrary, overexpression of AtPAO3 results to an increased but balanced production of both H2O2 and O2.-. These results suggest that the ratio of O2.-/H2O2 regulates respiratory chain in mitochondria, with PA-dependent production of O2.- by NADPH-oxidase tilting the balance of electron transfer chain in favor of the AOX pathway. In addition, AtPAO3 seems to be an important component in the regulating module of ROS homeostasis, while a conserved role for PA backconversion and ROS across kingdoms is discussed.

NADPH-dependent D-aldose reductases and xylose fermentation in Fusarium oxysporum

DEFF Research Database (Denmark)

Panagiotou, Gianni; Christakopoulos, P.

2004-01-01

for NADPH over NADH. In this study, the influence of aeration and the response to the addition of electron acceptors on xylose fermentation by F. oxysporum were also studied. The batch cultivation of F. oxysporum on xylose was performed under aerobic, anaerobic and oxygen-limited conditions in stirred tank...... conditions (0.3 vvm). When the artificial electron acceptor acetoin was added to an anaerobic batch fermentation of xylose by F. oxysporum, the ethanol yield increased while xylitol excretion was also decreased....

Freeform lens design for LED collimating illumination.

Science.gov (United States)

Chen, Jin-Jia; Wang, Te-Yuan; Huang, Kuang-Lung; Liu, Te-Shu; Tsai, Ming-Da; Lin, Chin-Tang

2012-05-07

We present a simple freeform lens design method for an application to LED collimating illumination. The method is derived from a basic geometric-optics analysis and construction approach. By using this method, a highly collimating lens with LED chip size of 1.0 mm × 1.0 mm and optical simulation efficiency of 86.5% under a view angle of ± 5 deg is constructed. To verify the practical performance of the lens, a prototype of the collimator lens is also made, and an optical efficiency of 90.3% with a beam angle of 4.75 deg is measured.

Resveratrol prevents high glucose-induced epithelial-mesenchymal transition in renal tubular epithelial cells by inhibiting NADPH oxidase/ROS/ERK pathway.

Science.gov (United States)

He, Ting; Guan, Xu; Wang, Song; Xiao, Tangli; Yang, Ke; Xu, Xinli; Wang, Junping; Zhao, Jinghong

2015-02-15

Resveratrol (RSV) is reported to have renoprotective activity against diabetic nephropathy, while the mechanisms underlying its function have not been fully elucidated. In this study, we investigate the effect and related mechanism of RSV against high glucose-induced epithelial to mesenchymal transition (EMT) in human tubular epithelial cells (HK-2). A typical EMT is induced by high glucose in HK-2 cells, accompanied by increased levels of reactive oxygen species (ROS). RSV exhibits a strong ability to inhibit high glucose-induced EMT by decreasing intracellular ROS levels via down-regulation of NADPH oxidase subunits NOX1 and NOX4. The activation of extracellular signal-regulated kinase (ERK1/2) is found to be involved in high glucose-induced EMT in HK-2 cells. RSV, like NADPH oxidase inhibitor diphenyleneiodonium, can block ERK1/2 activation induced by high glucose. Our results demonstrate that RSV is a potent agent against high glucose-induced EMT in renal tubular cells via inhibition of NADPH oxidase/ROS/ERK1/2 pathway. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

The low-field permanent magnet electrostatic plasma lens

International Nuclear Information System (INIS)

Goncharov, A.; Gorshkov, V.; Maslov, V.; Zadorozhny, V.; Brown, I.

2004-01-01

We describe the status of ongoing research and development of the electrostatic plasma lens as used for the manipulation of high current broad beams of heavy ions of moderate energy. In some collaborative work at Lawrence Berkeley National Laboratory the lens was used to good effect for carrying out high dose ion implantation processing. In the process of this work a very narrow range of low magnetic field was found for which the ion-optical characteristics of the lens improved markedly. Subsequent theoretical analysis and computer modeling has led to an understanding of this phenomenon. These serendipitous results open up some attractive possibilities for the development of a new compact and low cost plasma lens based on permanent magnets rather than on current-driven field coils surrounding the lens volume. The development of this kind of lens, including both very low noise and minimal spherical aberration effects, may lead to a tool suitable for use in the injection beam lines of high current heavy ion linear accelerators. Here we briefly review the lens fundamentals, some characteristics of focusing heavy ion beams at low magnetic fields, and summarize recent theoretical and experimental developments, with emphasis on the relevance and suitability of the lens for accelerator injection application

Precision lens assembly with alignment turning system

Science.gov (United States)

Ho, Cheng-Fang; Huang, Chien-Yao; Lin, Yi-Hao; Kuo, Hui-Jean; Kuo, Ching-Hsiang; Hsu, Wei-Yao; Chen, Fong-Zhi

2017-10-01

The poker chip assembly with high precision lens barrels is widely applied to ultra-high performance optical system. ITRC applies the poker chip assembly technology to the high numerical aperture objective lenses and lithography projection lenses because of its high efficiency assembly process. In order to achieve high precision lens cell for poker chip assembly, an alignment turning system (ATS) is developed. The ATS includes measurement, alignment and turning modules. The measurement module is equipped with a non-contact displacement sensor (NCDS) and an autocollimator (ACM). The NCDS and ACM are used to measure centration errors of the top and the bottom surface of a lens respectively; then the amount of adjustment of displacement and tilt with respect to the rotational axis of the turning machine for the alignment module can be determined. After measurement, alignment and turning processes on the ATS, the centration error of a lens cell with 200 mm in diameter can be controlled within 10 arcsec. Furthermore, a poker chip assembly lens cell with three sub-cells is demonstrated, each sub-cells are measured and accomplished with alignment and turning processes. The lens assembly test for five times by each three technicians; the average transmission centration error of assembly lens is 12.45 arcsec. The results show that ATS can achieve high assembly efficiency for precision optical systems.

THE BOSS EMISSION-LINE LENS SURVEY. IV. SMOOTH LENS MODELS FOR THE BELLS GALLERY SAMPLE

Energy Technology Data Exchange (ETDEWEB)

Shu, Yiping [National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012 (China); Bolton, Adam S.; Montero-Dorta, Antonio D.; Cornachione, Matthew A.; Zheng, Zheng; Brownstein, Joel R. [Department of Physics and Astronomy, University of Utah, 115 South 1400 East, Salt Lake City, UT 84112 (United States); Mao, Shude [Physics Department and Tsinghua Centre for Astrophysics, Tsinghua University, Beijing 100084 (China); Kochanek, Christopher S. [Department of Astronomy and Center for Cosmology and Astroparticle Physics, Ohio State University, Columbus, OH 43210 (United States); Pérez-Fournon, Ismael; Marques-Chaves, Rui [Instituto de Astrofísica de Canarias, C/Vía Láctea, s/n, E-38205 San Cristóbal de La Laguna, Tenerife (Spain); Oguri, Masamune [Research Center for the Early Universe, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Ménard, Brice, E-mail: yiping.shu@nao.cas.cn [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States)

2016-12-20

We present Hubble Space Telescope F606W-band imaging observations of 21 galaxy-Ly α emitter lens candidates in the Baryon Oscillation Spectroscopic Survey Emission-Line Lens Survey (BELLS) for the GALaxy-Ly α EmitteR sYstems (BELLS GALLERY) survey. Seventeen systems are confirmed to be definite lenses with unambiguous evidence of multiple imaging. The lenses are primarily massive early-type galaxies (ETGs) at redshifts of approximately 0.55, while the lensed sources are Ly α emitters (LAEs) at redshifts from two to three. Although most of the lens systems are well fit by smooth lens models consisting of singular isothermal ellipsoids in an external shear field, a thorough exploration of dark substructures in the lens galaxies is required. The Einstein radii of the BELLS GALLERY lenses are, on average, 60% larger than those of the BELLS lenses because of the much higher source redshifts. This will allow for a detailed investigation of the radius evolution of the mass profile in ETGs. With the aid of the average ∼13× lensing magnification, the LAEs are frequently resolved into individual star-forming knots with a wide range of properties. They have characteristic sizes from less than 100 pc to several kiloparsecs, rest-frame far-UV apparent AB magnitudes from 29.6 to 24.2, and typical projected separations of 500 pc to 2 kpc.

Role of Aquaporin 0 in lens biomechanics.

Science.gov (United States)

Sindhu Kumari, S; Gupta, Neha; Shiels, Alan; FitzGerald, Paul G; Menon, Anil G; Mathias, Richard T; Varadaraj, Kulandaiappan

2015-07-10

Maintenance of proper biomechanics of the eye lens is important for its structural integrity and for the process of accommodation to focus near and far objects. Several studies have shown that specialized cytoskeletal systems such as the beaded filament (BF) and spectrin-actin networks contribute to mammalian lens biomechanics; mutations or deletion in these proteins alters lens biomechanics. Aquaporin 0 (AQP0), which constitutes ∼45% of the total membrane proteins of lens fiber cells, has been shown to function as a water channel and a structural cell-to-cell adhesion (CTCA) protein. Our recent ex vivo study on AQP0 knockout (AQP0 KO) mouse lenses showed the CTCA function of AQP0 could be crucial for establishing the refractive index gradient. However, biomechanical studies on the role of AQP0 are lacking. The present investigation used wild type (WT), AQP5 KO (AQP5(-/-)), AQP0 KO (heterozygous KO: AQP0(+/-); homozygous KO: AQP0(-/-); all in C57BL/6J) and WT-FVB/N mouse lenses to learn more about the role of fiber cell AQPs in lens biomechanics. Electron microscopic images exhibited decreases in lens fiber cell compaction and increases in extracellular space due to deletion of even one allele of AQP0. Biomechanical assay revealed that loss of one or both alleles of AQP0 caused a significant reduction in the compressive load-bearing capacity of the lenses compared to WT lenses. Conversely, loss of AQP5 did not alter the lens load-bearing ability. Compressive load-bearing at the suture area of AQP0(+/-) lenses showed easy separation while WT lens suture remained intact. These data from KO mouse lenses in conjunction with previous studies on lens-specific BF proteins (CP49 and filensin) suggest that AQP0 and BF proteins could act co-operatively in establishing normal lens biomechanics. We hypothesize that AQP0, with its prolific expression at the fiber cell membrane, could provide anchorage for cytoskeletal structures like BFs and together they help to confer

Effect of infusion bottle height on lens power after lens refilling with and without a plug

NARCIS (Netherlands)

Koopmans, SA; Terwee, T; Haitjema, HJ; Kooijman, AC; Barkhof, J

2003-01-01

Purpose: To evaluate the influence of intraoperative infusion bottle height on the power of refilled pig lenses. Setting: Research Laboratory, Pharmacia Intraocular Lens Manufacturing Plant, Groningen, The Netherlands. Methods: This study comprised 2 groups of pig eyes. In 1 group, the lens was

Chapter 03: Correct use of a hand lens

Science.gov (United States)

Alex Wiedenhoeft

2011-01-01

A hand lens is a powerful tool for the identification of wood, but like all tools it must be used correctly to take full advantage of its powers. The hand lens has two main parts, a lens that magnifies the object of interest (generally we use 10X or 14X lenses in wood identification; a 14X lens is recommended for use with this manual) and a housing to hold and protect...

The neutron silicon lens. An update of the thermal neutron lens results

International Nuclear Information System (INIS)

Johnson, M.W.; Daymond, M.R.

2001-01-01

This paper introduces the concept of the Neutron Silicon Lens (NSL) and provides and update on the experimental results achieved to date. The NSL design is a cylindrical neutron lens based on the use of multiple neutron mirrors supported and separated by silicon wafers. Such lenses would have many applications in both the primary and scattered beams on neutron instruments, and would lead to immediate improvements where the sample to be illuminated is small, as in high pressure or engineering strain scanning instruments. (author)

The neutron silicon lens. An update of the thermal neutron lens results

Energy Technology Data Exchange (ETDEWEB)

Johnson, M.W.; Daymond, M.R. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire (United Kingdom)

2001-03-01

This paper introduces the concept of the Neutron Silicon Lens (NSL) and provides and update on the experimental results achieved to date. The NSL design is a cylindrical neutron lens based on the use of multiple neutron mirrors supported and separated by silicon wafers. Such lenses would have many applications in both the primary and scattered beams on neutron instruments, and would lead to immediate improvements where the sample to be illuminated is small, as in high pressure or engineering strain scanning instruments. (author)

Identification of a mitochondrial external NADPH dehydrogenase by overexpression in transgenic ¤Nicotiana sylvestris¤

DEFF Research Database (Denmark)

Michalecka, A.M.; Agius, S.C.; Møller, I.M.

2004-01-01

The plant respiratory chain contains a complex setup of non-energy conserving NAD(P)H dehydrogenases, the physiological consequences of which are highly unclear. An expression construct for the potato (Solanum tuberosum L., cv. Desiree) ndb1 gene, a homologue of bacterial and fungal type II NAD...

Axotomy increases NADPH-diaphorase activity in the dorsal root ganglia and lumbar spinal cord of the turtle Trachemys dorbigni

Directory of Open Access Journals (Sweden)

Partata W.A.

1999-01-01

Full Text Available Seven days after transection of the sciatic nerve NADPH-diaphorase activity increased in the small and medium neurons of the dorsal root ganglia of the turtle. However, this increase was observed only in medium neurons for up to 90 days. At this time a bilateral increase of NADPH-diaphorase staining was observed in all areas and neuronal types of the dorsal horn, and in positive motoneurons in the lumbar spinal cord, ipsilateral to the lesion. A similar increase was also demonstrable in spinal glial and endothelial cells. These findings are discussed in relation to the role of nitric oxide in hyperalgesia and neuronal regeneration or degeneration.

Axotomy increases NADPH-diaphorase activity in the dorsal root ganglia and lumbar spinal cord of the turtle Trachemys dorbigni.

Science.gov (United States)

Partata, W A; Krepsky, A M; Marques, M; Achaval, M

1999-04-01

Seven days after transection of the sciatic nerve NADPH-diaphorase activity increased in the small and medium neurons of the dorsal root ganglia of the turtle. However, this increase was observed only in medium neurons for up to 90 days. At this time a bilateral increase of NADPH-diaphorase staining was observed in all areas and neuronal types of the dorsal horn, and in positive motoneurons in the lumbar spinal cord, ipsilateral to the lesion. A similar increase was also demonstrable in spinal glial and endothelial cells. These findings are discussed in relation to the role of nitric oxide in hyperalgesia and neuronal regeneration or degeneration.

The distribution of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) in the medulla oblongata, spinal cord, cranial and spinal nerves of frog, Microhyla ornata.

Science.gov (United States)

Jadhao, Arun G; Biswas, Saikat P; Bhoyar, Rahul C; Pinelli, Claudia

2017-04-01

Nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) enzymatic activity has been reported in few amphibian species. In this study, we report its unusual localization in the medulla oblongata, spinal cord, cranial nerves, spinal nerves, and ganglions of the frog, Microhyla ornata. In the rhombencephalon, at the level of facial and vagus nerves, the NADPH-d labeling was noted in the nucleus of the abducent and facial nerves, dorsal nucleus of the vestibulocochlear nerve, the nucleus of hypoglossus nerve, dorsal and lateral column nucleus, the nucleus of the solitary tract, the dorsal field of spinal grey, the lateral and medial motor fields of spinal grey and radix ventralis and dorsalis (2-10). Many ependymal cells around the lining of the fourth ventricle, both facial and vagus nerves and dorsal root ganglion, were intensely labeled with NADPH-d. Most strikingly the NADPH-d activity was seen in small and large sized motoneurons in both medial and lateral motor neuron columns on the right and left sides of the brain. This is the largest stained group observed from the caudal rhombencephalon up to the level of radix dorsalis 10 in the spinal cord. The neurons were either oval or elongated in shape with long processes and showed significant variation in the nuclear and cellular diameter. A massive NADPH-d activity in the medulla oblongata, spinal cord, and spinal nerves implied an important role of this enzyme in the neuronal signaling as well as in the modulation of motor functions in the peripheral nervous systems of the amphibians. Copyright © 2017 Elsevier B.V. All rights reserved.

Perceptron Mistake Bounds

OpenAIRE

Mohri, Mehryar; Rostamizadeh, Afshin

2013-01-01

We present a brief survey of existing mistake bounds and introduce novel bounds for the Perceptron or the kernel Perceptron algorithm. Our novel bounds generalize beyond standard margin-loss type bounds, allow for any convex and Lipschitz loss function, and admit a very simple proof.

Preferential inhibition of the plasma membrane NADH oxidase (NOX) activity by diphenyleneiodonium chloride with NADPH as donor

Science.gov (United States)

Morre, D. James

2002-01-01

The cell-surface NADH oxidase (NOX) protein of plant and animal cells will utilize both NADH and NADPH as reduced electron donors for activity. The two activities are distinguished by a differential inhibition by the redox inhibitor diphenyleneiodonium chloride (DPI). Using both plasma membranes and cells, activity with NADPH as donor was markedly inhibited by DPI at submicromolar concentrations, whereas with NADH as donor, DPI was much less effective or had no effect on the activity. The possibility of the inhibition being the result of two different enzymes was eliminated by the use of a recombinant NOX protein. The findings support the concept that NOX proteins serve as terminal oxidases for plasma membrane electron transport involving cytosolic reduced pyridine nucleotides as the natural electron donors and with molecular oxygen as the electron acceptor.

Expression of a cytoplasmic transhydrogenase in Saccharomyces cerevisiae results in formation of 2-oxoglutarate due to depletion of the NADPH pool

DEFF Research Database (Denmark)

Nissen, T.L.; Anderlund, M.; Nielsen, Jens

2001-01-01

The intracellular redox state of a cell is to a large extent defined by the concentration ratios of the two pyridine nucleotide systems NADH/NAD(+) and NADPH/ADP(+) and has a significant influence on product formation in microorganisms. The enzyme pyridine nucleotide transhydrogenase, which can...... cultivations in high-performance bioreactors were carried out in order to allow quantitative analysis of the effect of transhydrogenase expression on product formation and on the intracellular concentrations of NADH, NAD(+), NADPH and NADP(+). A specific transhydrogenase activity of 4.53 U/mg protein...

Novel Scanning Lens Instrument for Evaluating Fresnel Lens Performance: Equipment Development and Initial Results (Presentation)

Energy Technology Data Exchange (ETDEWEB)

Herrero, R.; Miller, D. C.; Kurtz, S. R.; Anton, I.; Sala, G.

2013-07-01

A system dedicated to the optical transmittance characterization of Fresnel lenses has been developed at NREL, in collaboration with the UPM. The system quantifies the optical efficiency of the lens by generating a performance map. The shape of the focused spot may also be analyzed to understand change in the lens performance. The primary instrument components (lasers and CCD detector) have been characterized to confirm their capability for performing optical transmittance measurements. Measurements performed on SoG and PMMA lenses subject to a variety of indoor conditions (e.g., UV and damp heat) identified differences in the optical efficiency of the evaluated lenses, demonstrating the ability of the Scanning Lens Instrument (SLI) to distinguish between the aged lenses.

Method for producing an isoplanatic aspheric monofocal intraocular lens, and resul ting lens

OpenAIRE

Barbero, Sergio; Marcos, Susana; Dorronsoro, Carlos; Montejo, Javier; Salazar Salegui, Pedro

2010-01-01

[EN] The invention can be used to obtain isoplanatic aspheric mono focal intraocular lenses in a viewing range of up to 25° (preferably up to 10°). The method comprises the following steps: l. mathematical defmition of an aphakic eye model; 2. mathematical definition of an intraocular lens model; 3. mathematical defmition of the implantation of the lens; 4. mathematical defmition of the merit function; 5. definition of the contour conditions; 6. defmition of a measurement for charact...

Superoxide production and expression of NAD(P)H oxidases by transformed and primary human colonic epithelial cells

DEFF Research Database (Denmark)

Perner, A; Andresen, Lars; Pedersen, G

2003-01-01

Superoxide (O(2)(-)) generation through the activity of reduced nicotinamide dinucleotide (NADH) or reduced nicotinamide dinucleotide phosphate (NADPH) oxidases has been demonstrated in a variety of cell types, but not in human colonic epithelial cells....

Multipoint photonic doppler velocimetry using optical lens elements

Science.gov (United States)

Frogget, Brent Copely; Romero, Vincent Todd

2014-04-29

A probe including a fisheye lens is disclosed to measure the velocity distribution of a moving surface along many lines of sight. Laser light, directed to the surface and then reflected back from the surface, is Doppler shifted by the moving surface, collected into fisheye lens, and then directed to detection equipment through optic fibers. The received light is mixed with reference laser light and using photonic Doppler velocimetry, a continuous time record of the surface movement is obtained. An array of single-mode optical fibers provides an optic signal to an index-matching lens and eventually to a fisheye lens. The fiber array flat polished and coupled to the index-matching lens using index-matching gel. Numerous fibers in a fiber array project numerous rays through the fisheye lens which in turn project many measurement points at numerous different locations to establish surface coverage over a hemispherical shape with very little crosstalk.

Disassembly of the lens fiber cell nucleus to create a clear lens: the p27 descent

Science.gov (United States)

The eye lens is unique among tissues: it is transparent, does not form tumors, and the majority of its cells degrade their organelles, including their cell nuclei. A mystery for over a century, there has been considerable recent progress in elucidating mechanisms of lens fiber cell denucleation (LFC...

The sloan lens acs survey. II. Stellar populations and internal structure of early-type lens galaxies

NARCIS (Netherlands)

Treu, Tommaso; Koopmans, Léon V.; Bolton, Adam S.; Burles, Scott; Moustakas, Leonidas A.

2006-01-01

We use HST images to derive effective radii and effective surface brightnesses of 15 early-type (E+S0) lens galaxies identified by the SLACS Survey. Our measurements are combined with stellar velocity dispersions from the SDSS database to investigate for the first time the distribution of lens

Automated Fresnel lens tester system

Energy Technology Data Exchange (ETDEWEB)

Phipps, G.S.

1981-07-01

An automated data collection system controlled by a desktop computer has been developed for testing Fresnel concentrators (lenses) intended for solar energy applications. The system maps the two-dimensional irradiance pattern (image) formed in a plane parallel to the lens, whereas the lens and detector assembly track the sun. A point detector silicon diode (0.5-mm-dia active area) measures the irradiance at each point of an operator-defined rectilinear grid of data positions. Comparison with a second detector measuring solar insolation levels results in solar concentration ratios over the image plane. Summation of image plane energies allows calculation of lens efficiencies for various solar cell sizes. Various graphical plots of concentration ratio data help to visualize energy distribution patterns.

Perubahan Sosial Berbasis Tasawuf: Studi Kasus Fethullah Gülen Dan Gülen Movement

Directory of Open Access Journals (Sweden)

Sulaiman Sulaiman

2016-06-01

Full Text Available Abstract: This article aims at analyzing Fethullah Gülen and the Gülen Movement which have succeeded in performing social change based on the teaching of Sufism. He did Sufism creativity in order that Sufism teaching was able to respond the changes that occur in the modernlife. He believed that, only by reinterpretation and contextualization of Sufism, the spiritual dimension of Islam would be able to perform the transformation or social change among the Muslims. Therefore, by using Max Weber’s theory of social action, this paper will analyze three key teachings of Sufism of Gülen: ascetic (zuhd, inbisat (expansion, and hizmet. Based on the Weber's theory, Gülen occupied a very central and authoritative position: agent/actor, action and meaning. As a source of meaning and interpreter of meaning, the key concepts of Sufism were transformed by Gülen to the internal and external communities so that they had made a move to do social movements and humanity. For the followers of Gülen, the movement was called the Gülen Movement or the Hizmet Movement which was engaged in the fields of education, health care, humanitarian assistance, and the mass media. All forms of movement were entirely based on the spiritual values of Islam that had been formulated by Gülen. الملخص: يهدف هذا البحث إلى تحليل شخصية فتح الله غولن وحركته الذي تمكن من القيام بالتغيير الاجتماعي على أساس التعاليم الصوفية. إن فتح الله غولن قام بإحياء التصوف في صورته الجدّية والحيوية في حياة الإنسان المعاصر. ويعتقد أن إعادة التفسير لتعاليم التصوف مع مراعاة الواقع قادرة على التغيير الاجتماعي بين المسلمين. من أجل ذلك، أن استخدام نظرية ويبر، يمكن تحليل تعاليم التصوف الثلاثة �

Characteristics of soft X-ray lens

International Nuclear Information System (INIS)

Qin Yi

2007-12-01

A soft X-lens was devised with waveguide X-ray optics of total external reflection (TER). The lens consists of a stack of 1 387 TER waveguides with inner diameter of 0.45 mm and outer diameter of 0.60 mm. With the help of plasma sources of soft X-ray radiation, high density of pure soft X-ray radiation (without plasma expansion fragments) with broad-band spectral range can be obtained at the focus of the lens. As laser-plasma is considered, the radiation density of 1.3 x 10 5 W/cm 2 is obtained, the transmission coefficient is 18.6%, the ratio of the density at the focus with and without the lens is 1000 and the radiation capture is 28.9 degree. The density of 0.5 TW/cm 2 can be obtained as far as Qiang-Guang I facility is considered. (authors)

Development of an accommodating intra-ocular lens - In vitro prevention of re-growth of pig and rabbit lens capsule epithelial cells

NARCIS (Netherlands)

van Kooten, Theo G.; Koopmans, Steven; Terwee, Thom; Norrby, Sverker; Hooymans, J. M. M.; Busscher, Henk J.

2006-01-01

Cataract surgery is routinely performed to replace the clouded lens by a rigid polymeric intra-ocular lens unable to accommodate. By implanting a silicone gel into an intact capsular bag the accommodating properties of the natural lens can be maintained or enhanced. The implantation success of

Tea polyphenols alleviate high fat and high glucose-induced endothelial hyperpermeability by attenuating ROS production via NADPH oxidase pathway.

Science.gov (United States)

Zuo, Xuezhi; Tian, Chong; Zhao, Nana; Ren, Weiye; Meng, Yi; Jin, Xin; Zhang, Ying; Ding, Shibin; Ying, Chenjiang; Ye, Xiaolei

2014-03-02

Hyperglycemia-induced endothelial hyperpermeability is crucial to cardiovascular disorders and macro-vascular complications in diabetes mellitus. The objective of this study is to investigate the effects of green tea polyphenols (GTPs) on endothelial hyperpermeability and the role of nicotinamide adenine dinucleotide phosphate (NADPH) pathway. Male Wistar rats fed on a high fat diet (HF) were treated with GTPs (0, 0.8, 1.6, 3.2 g/L in drinking water) for 26 weeks. Bovine aortic endothelial cells (BAECs) were treated with high glucose (HG, 33 mmol/L) and GTPs (0.0, 0.4, or 4 μg/mL) for 24 hours in vitro. The endothelial permeabilities in rat aorta and monolayer BAECs were measured by Evans blue injection method and efflux of fluorescein isothiocyanate (FITC)-dextran, respectively. The reactive oxygen species (ROS) levels in rat aorta and monolayer BAECs were measured by dihydroethidium (DHE) and 2', 7'-dichloro-fluorescein diacetate (DCFH-DA) fluorescent probe, respectively. Protein levels of NADPH oxidase subunits were determined by Western-blot. HF diet-fed increased the endothelial permeability and ROS levels in rat aorta while HG treatments increased the endothelial permeability and ROS levels in cultured BAECs. Co-treatment with GTPs alleviated those changes both in vivo and in vitro. In in vitro studies, GTPs treatments protected against the HG-induced over-expressions of p22phox and p67phox. Diphenylene iodonium chloride (DPI), an inhibitor of NADPH oxidase, alleviated the hyperpermeability induced by HG. GTPs could alleviate endothelial hyperpermeabilities in HF diet-fed rat aorta and in HG treated BAECs. The decrease of ROS production resulting from down-regulation of NADPH oxidase contributed to the alleviation of endothelial hyperpermeability.

Effect of X-rays and u.v.-light on the levels of NAD(P), NAD(P)H and hydroxyproline in Pinus silvestris pollen

International Nuclear Information System (INIS)

Zelles, L.

1978-01-01

Pollen grains of Pinus Silvestris were irradiated with stimulating and inhibiting doses of X-rays and u.v.-light and the levels of NAD(P), NAD(P)H and hydroxyproline determined during tube growth. Pollen grains irradiated with stimulating doses of X-rays and u.v.-light developed longer tubes, while grains irradiated with inhibiting doses of X-rays and u.v.-light developed shorter tubes than the unirradiated controls. After 32 hr of incubation, the levels of NAD(P), NAD(P)H and hydroxyproline were at their lowest compared with unirradiated pollen. In samples with stimulating doses of irradiation NAD(P) reached its maximum earlier than in samples with inhibiting irradiation. The ratio between the concentrations of NAD(P) and NAD(P)H in the irradiated samples was higher than in the unirradiated control. The hydroxyproline content was higher in irradiated than in unirradiated pollen. (author)

Photon nanojet lens: design, fabrication and characterization

International Nuclear Information System (INIS)

Xu, Chen; Zhang, Sichao; Shao, Jinhai; Lu, Bing-Rui; Chen, Yifang; Mehfuz, Reyad; Drakeley, Stacey; Huang, Fumin

2016-01-01

In this paper, a novel nanolens with super resolution, based on the photon nanojet effect through dielectric nanostructures in visible wavelengths, is proposed. The nanolens is made from plastic SU-8, consisting of parallel semi-cylinders in an array. This paper focuses on the lens designed by numerical simulation with the finite-difference time domain method and nanofabrication of the lens by grayscale electron beam lithography combined with a casting/bonding/lift-off transfer process. Monte Carlo simulation for injected charge distribution and development modeling was applied to define the resultant 3D profile in PMMA as the template for the lens shape. After the casting/bonding/lift-off process, the fabricated nanolens in SU-8 has the desired lens shape, very close to that of PMMA, indicating that the pattern transfer process developed in this work can be reliably applied not only for the fabrication of the lens but also for other 3D nanopatterns in general. The light distribution through the lens near its surface was initially characterized by a scanning near-field optical microscope, showing a well defined focusing image of designed grating lines. Such focusing function supports the great prospects of developing a novel nanolithography based on the photon nanojet effect. (paper)

Protein synthesis in x-irradiated rabbit lens

International Nuclear Information System (INIS)

Garadi, R.; Foltyn, A.R.; Giblin, F.J.; Reddy, V.N.

1984-01-01

The present study deals with the incorporation of 35 S methionine into lens crystallins as a function of time after x-irradiation. Crystallin synthesis is first affected approximately 4 weeks following x-irradiation. This coincides with the time period at which the ratio of the two cations in the lens is affected, as shown in earlier studies. A greater decrease in 35 S-methionine incorporation into crystallins is observed between 5-7 weeks following x-irradiation in good agreement with a cation imbalance at these time intervals. These studies also revealed for the first time that the change in cation distribution can affect not only crystallin synthesis, but also the synthesis of certain polypeptides of lens membranes. No alteration in protein synthesis could be detected in lens epithelium even after 7 weeks following irradiation. In addition to the effect of Na+ and K+ levels on protein synthesis, an impaired transport of amino acids into the x-rayed lens was also found to be a factor in the observed reduction in synthesis of the crystallin, cytoskeletal and membrane proteins of the fiber cells. It is concluded that Na+/K+ ratio as well as the availability of amino acids in the lens are important factors in protein synthesis of x-ray cataracts

21 CFR 886.1410 - Ophthalmic trial lens clip.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic trial lens clip. 886.1410 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1410 Ophthalmic trial lens clip. (a) Identification. An ophthalmic trial lens clip is a device intended to hold prisms, spheres, cylinders, or...

21 CFR 886.1415 - Ophthalmic trial lens frame.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic trial lens frame. 886.1415 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1415 Ophthalmic trial lens frame. (a) Identification. An opthalmic trial lens frame is a mechanical device intended to hold trial lenses for vision...

An adjustable electron achromat for cathode lens microscopy

Energy Technology Data Exchange (ETDEWEB)

Tromp, R.M., E-mail: rtromp@us.ibm.com [IBM T.J. Watson Research Center, 1101 Kitchawan Road, Yorktown Heights, NY 10598 (United States); Leiden Institute of Physics, Kamerlingh Onnes Laboratory, Niels Bohrweg 2, 2333 CA Leiden (Netherlands)

2015-12-15

Chromatic aberration correction in light optics began with the invention of a two-color-corrected achromatic crown/flint lens doublet by Chester Moore Hall in 1730. Such color correction is necessary because any single glass shows dispersion (i.e. its index of refraction changes with wavelength), which can be counteracted by combining different glasses with different dispersions. In cathode lens microscopes (such as Photo Electron Emission Microscopy – PEEM) we encounter a similar situation, where the chromatic aberration coefficient of the cathode lens shows strong dispersion, i.e. depends (non-linearly) on the energy with which the electrons leave the sample. Here I show how a cathode lens in combination with an electron mirror can be configured as an adjustable electron achromat. The lens/mirror combination can be corrected at two electron energies by balancing the settings of the electron mirror against the settings of the cathode lens. The achromat can be adjusted to deliver optimum performance, depending on the requirements of a specific experiment. Going beyond the achromat, an apochromat would improve resolution and transmission by a very significant margin. I discuss the requirements and outlook for such a system, which for now remains a wish waiting for fulfilment. - Highlights: • The properties of cathode objective lens plus electron mirror are discussed. • In analogy with light-optical achromats, cathode lens plus mirror can be configured as an electron achromat. • Unlike light optics, the electron achromat can be adjusted to best fulfill experimental requirements.

Fermat's least-time principle and the embedded transparent lens

Science.gov (United States)

Kantowski, R.; Chen, B.; Dai, X.

2013-10-01

We present a simplified version of the lowest-order embedded point mass gravitational lens theory and then make the extension of this theory to any embedded transparent lens. Embedding a lens effectively reduces the gravitational potential’s range, i.e., partially shields the lensing potential because the lens mass is made a contributor to the mean mass density of the Universe and not simply superimposed upon it. We give the time-delay function for the embedded point mass lens from which we can derive the simplified lens equation by applying Fermat’s least-time principle. Even though rigorous derivations are only made for the point mass in a flat background, the generalization of the lens equation to lowest order for any distributed lens in any homogeneous background is obvious. We find from this simplified theory that embedding can introduce corrections above the few percent level in weak lensing shears caused by large clusters but only at large impacts. The potential part of the time delay is also affected in strong lensing at the few percent level. Additionally we again confirm that the presence of a cosmological constant alters the gravitational deflection of passing photons.

Lens regeneration in axolotl: new evidence of developmental plasticity

Directory of Open Access Journals (Sweden)

Suetsugu-Maki Rinako

2012-12-01

Full Text Available Abstract Background Among vertebrates lens regeneration is most pronounced in newts, which have the ability to regenerate the entire lens throughout their lives. Regeneration occurs from the dorsal iris by transdifferentiation of the pigment epithelial cells. Interestingly, the ventral iris never contributes to regeneration. Frogs have limited lens regeneration capacity elicited from the cornea during pre-metamorphic stages. The axolotl is another salamander which, like the newt, regenerates its limbs or its tail with the spinal cord, but up until now all reports have shown that it does not regenerate the lens. Results Here we present a detailed analysis during different stages of axolotl development, and we show that despite previous beliefs the axolotl does regenerate the lens, however, only during a limited time after hatching. We have found that starting at stage 44 (forelimb bud stage lens regeneration is possible for nearly two weeks. Regeneration occurs from the iris but, in contrast to the newt, regeneration can be elicited from either the dorsal or the ventral iris and, occasionally, even from both in the same eye. Similar studies in the zebra fish concluded that lens regeneration is not possible. Conclusions Regeneration of the lens is possible in the axolotl, but differs from both frogs and newts. Thus the axolotl iris provides a novel and more plastic strategy for lens regeneration.

FEA Analysis of AP-0 Target Hall Collection Lens (Current Design)

International Nuclear Information System (INIS)

Hurh, P.G.; Tang, Z.

2001-01-01

Collection Lens, this material is lithium (Li). The central conductor cylinder is a lithium cylinder 1 cm in radius and about 14 cm long. Figure 1 shows this cylinder in a cross-section view of the Collection Lens. Surrounding the central cylinder is a jacket of titanium alloy (6Al-4V ELI) called the septum. The septum's purpose is to contain the lithium against various thermal and magnetic forces while allowing cooling (melting point of Li is 180.5 C) by an annular water passage. The ends of the Li cylinder are bound by end windows made of beryllium (Be) and a thin titanium (ti) foil. The foil protects the Be from the corrosive effects of Li and the Be window provides the structural support. The two end windows sit in pockets in the ends of two larger steel cylinders or body halves. The body halves are separated from each other by ceramic spacers. The body halves, septum and end windows are connected to each other by nickel (Ni) seals which preserve the boundary of the lithium conductor. Force required to make these seals is provided by eight Ti 6Al-4V ELI tie rods which traverse the entire assembly. These tie rods also resist magnetic forces that attempt to separate the body halves during the current pulse. There are several insulating components that are used to isolate one side of the lens from the other and force the current through the central Li conductor. The volumes of Li at each end of the central conductor cylinder outside the septum but inside the body halves are called buffer volumes. These buffer volumes serve two roles. One, they provide a low resistance current path to the end of the central conductor cylinder. Two, they provide a volume for Li to expand into during the current pulse. For the latter it is assumed that magnetic forces and thermal strains will force lithium from the central cylinder and into the buffer volumes during the current pulse. There are several loads on the Lens that are developed during a current pulse. High magnetic loads act

The transcriptional regulator NtrC controls glucose-6-phosphate dehydrogenase expression and polyhydroxybutyrate synthesis through NADPH availability in Herbaspirillum seropedicae.

Science.gov (United States)

Sacomboio, Euclides Nenga Manuel; Kim, Edson Yu Sin; Correa, Henrique Leonardo Ruchaud; Bonato, Paloma; Pedrosa, Fabio de Oliveira; de Souza, Emanuel Maltempi; Chubatsu, Leda Satie; Müller-Santos, Marcelo

2017-10-19

The NTR system is the major regulator of nitrogen metabolism in Bacteria. Despite its broad and well-known role in the assimilation, biosynthesis and recycling of nitrogenous molecules, little is known about its role in carbon metabolism. In this work, we present a new facet of the NTR system in the control of NADPH concentration and the biosynthesis of molecules dependent on reduced coenzyme in Herbaspirillum seropedicae SmR1. We demonstrated that a ntrC mutant strain accumulated high levels of polyhydroxybutyrate (PHB), reaching levels up to 2-fold higher than the parental strain. In the absence of NtrC, the activity of glucose-6-phosphate dehydrogenase (encoded by zwf) increased by 2.8-fold, consequently leading to a 2.1-fold increase in the NADPH/NADP + ratio. A GFP fusion showed that expression of zwf is likewise controlled by NtrC. The increase in NADPH availability stimulated the production of polyhydroxybutyrate regardless the C/N ratio in the medium. The mutant ntrC was more resistant to H 2 O 2 exposure and controlled the propagation of ROS when facing the oxidative condition, a phenotype associated with the increase in PHB content.

21 CFR 886.1405 - Ophthalmic trial lens set.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic trial lens set. 886.1405 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1405 Ophthalmic trial lens set. (a) Identification. An ophthalmic trial lens set is a device that is a set of lenses of various dioptric powers...

Computer optimization of retarding lens systems for ESCA spectrometers

International Nuclear Information System (INIS)

Wannberg, B.; Skoellermo, A.

1977-01-01

The performance of four-element electrostatic lenses as retarding systems between source and analyzer in ESCA spectrometers is calculated. The potential distribution in the lens is defined by an axial potential of the type phi(z)=V 0 +Σ(Vsub(i)-Vsub(i-1))/2 - tanh (ω/asub(i)(z-zsub(i))). For a given general shape of the lens and a given retardation ratio, the potentials of the two middle electrodes are fitted to give a paraxial image with a prescribed magnification at the exit slit of the lens system. The equipotential surfaces forming the electrodes are found by calculating the potential in an off-axis point, using the series expansion. All third-order geometrical and first-order chromatic aberrations of the lenses are calculated and used together with the second-order aberrations of the analyzer to calculate optimum dimensions of the lens elements and of the emittance-defining slits. A computer program, of which one part calculates the lens properties and one the properties of the entire system lens-analyzer, is described. Two lens systems are presented in some detail. The first one is intended for use with a hemispherical electrostatic analyzer. The angular acceptance is here defined by an aperture stop inside the lens. In this system, the image position and magnification can be kept constant for retardation ratios at least between 1:2 and 60:1, with moderate potentials on the middle electrodes. The second lens system is designed for a magnetic spectrometer of the π√2-type. Here, the central trajectory in the lens is slightly curved by the magnetic field, and the angular acceptance is defined by a baffle after the lens. This system is optimized for a constant retardation ratio of 5:1. (Auth.)

Candidate gravitational microlensing events for future direct lens imaging

International Nuclear Information System (INIS)

Henderson, C. B.; Gould, A.; Gaudi, B. S.; Park, H.; Han, C.; Sumi, T.; Koshimoto, N.; Udalski, A.; Tsapras, Y.; Bozza, V.; Abe, F.; Fukunaga, D.; Itow, Y.; Masuda, K.; Bennett, D. P.; Bond, I. A.; Ling, C. H.; Botzler, C. S.; Freeman, M.; Fukui, A.

2014-01-01

The mass of the lenses giving rise to Galactic microlensing events can be constrained by measuring the relative lens-source proper motion and lens flux. The flux of the lens can be separated from that of the source, companions to the source, and unrelated nearby stars with high-resolution images taken when the lens and source are spatially resolved. For typical ground-based adaptive optics (AO) or space-based observations, this requires either inordinately long time baselines or high relative proper motions. We provide a list of microlensing events toward the Galactic bulge with high relative lens-source proper motion that are therefore good candidates for constraining the lens mass with future high-resolution imaging. We investigate all events from 2004 to 2013 that display detectable finite-source effects, a feature that allows us to measure the proper motion. In total, we present 20 events with μ ≳ 8 mas yr –1 . Of these, 14 were culled from previous analyses while 6 are new, including OGLE-2004-BLG-368, MOA-2005-BLG-36, OGLE-2012-BLG-0211, OGLE-2012-BLG-0456, MOA-2012-BLG-532, and MOA-2013-BLG-029. In ≲12 yr from the time of each event the lens and source of each event will be sufficiently separated for ground-based telescopes with AO systems or space telescopes to resolve each component and further characterize the lens system. Furthermore, for the most recent events, comparison of the lens flux estimates from images taken immediately to those estimated from images taken when the lens and source are resolved can be used to empirically check the robustness of the single-epoch method currently being used to estimate lens masses for many events.

Candidate gravitational microlensing events for future direct lens imaging

Energy Technology Data Exchange (ETDEWEB)

Henderson, C. B.; Gould, A.; Gaudi, B. S. [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Park, H.; Han, C. [Department of Physics, Institute for Astrophysics, Chungbuk National University, Cheongju 371-763 (Korea, Republic of); Sumi, T.; Koshimoto, N. [Department of Earth and Space Science, Osaka University, Osaka 560-0043 (Japan); Udalski, A. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Tsapras, Y. [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102, Goleta, CA 93117 (United States); Bozza, V. [Department of Physics, University of Salerno, I-84084 Fisciano (Italy); Abe, F.; Fukunaga, D.; Itow, Y.; Masuda, K. [Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya 464-8601 (Japan); Bennett, D. P. [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556-5670 (United States); Bond, I. A.; Ling, C. H. [Institute of Information and Mathematical Sciences, Massey University, Private Bag 102-904, North Shore Mail Centre, Auckland 0745 (New Zealand); Botzler, C. S.; Freeman, M. [Department of Physics, University of Auckland, Private Bag 92-019, Auckland 1001 (New Zealand); Fukui, A. [School of Chemical and Physical Sciences, Victoria University, Wellington 6140 (New Zealand); Collaboration: MOA Collaboration; OGLE Collaboration; μFUN Collaboration; RoboNet Collaboration; and others

2014-10-10

The mass of the lenses giving rise to Galactic microlensing events can be constrained by measuring the relative lens-source proper motion and lens flux. The flux of the lens can be separated from that of the source, companions to the source, and unrelated nearby stars with high-resolution images taken when the lens and source are spatially resolved. For typical ground-based adaptive optics (AO) or space-based observations, this requires either inordinately long time baselines or high relative proper motions. We provide a list of microlensing events toward the Galactic bulge with high relative lens-source proper motion that are therefore good candidates for constraining the lens mass with future high-resolution imaging. We investigate all events from 2004 to 2013 that display detectable finite-source effects, a feature that allows us to measure the proper motion. In total, we present 20 events with μ ≳ 8 mas yr{sup –1}. Of these, 14 were culled from previous analyses while 6 are new, including OGLE-2004-BLG-368, MOA-2005-BLG-36, OGLE-2012-BLG-0211, OGLE-2012-BLG-0456, MOA-2012-BLG-532, and MOA-2013-BLG-029. In ≲12 yr from the time of each event the lens and source of each event will be sufficiently separated for ground-based telescopes with AO systems or space telescopes to resolve each component and further characterize the lens system. Furthermore, for the most recent events, comparison of the lens flux estimates from images taken immediately to those estimated from images taken when the lens and source are resolved can be used to empirically check the robustness of the single-epoch method currently being used to estimate lens masses for many events.

The role of brassinosteroids in the regulation of the plasma membrane H+-ATPase and NADPH oxidase under cadmium stress.

Science.gov (United States)

Jakubowska, Dagmara; Janicka, Małgorzata

2017-11-01

The present research aim was to define the role of brassinosteroids (BRs) in plant adaptation to cadmium stress. We observed a stimulating effect of exogenous BR on the activity of two plasma membrane enzymes which play a key role in plants adaptation to cadmium stress, H + -ATPase (EC 3.6.3.14) and NADPH oxidase (EC 1.6.3.1). Using anti-phosphothreonine antibody we showed that modification of PM H + -ATPase activity under BR action could result from phosphorylation of the enzyme protein. Also the relative expression of genes encoding both PM H + -ATPase and NADPH oxidase was affected by BR. To confirm the role of BR in the cadmium stimulating effect on activity of both studied plasma membrane enzymes, an assay in the presence of a BR biosynthesis inhibitor (propiconazole) was performed. Moreover, as a tool in our work we used commercially available plant mutants unable to BR biosynthesis or with dysfunctional BR signaling pathway, to further confirm participation of BR in plant adaptation to heavy metal stress. Presented results demonstrate some elements of the brassinosteroid-induced pathway activated under cadmium stress, wherein H + -ATPase and NADPH oxidase are key factors. Copyright © 2017 Elsevier B.V. All rights reserved.

NADPH oxidase is not an essential mediator of oxidative stress or liver injury in murine MCD diet-induced steatohepatitis.

Science.gov (United States)

dela Peña, Aileen; Leclercq, Isabelle A; Williams, Jacqueline; Farrell, Geoffrey C

2007-02-01

Hepatic oxidative stress is a key feature of metabolic forms of steatohepatitis, but the sources of pro-oxidants are unclear. The NADPH oxidase complex is critical for ROS generation in inflammatory cells; loss of any one component (e.g., gp91phox) renders NADPH oxidase inactive. We tested whether activated inflammatory cells contribute to oxidant stress in steatohepatitis. gp91phox-/- and wildtype (wt) mice were fed a methionine and choline-deficient (MCD) diet. Serum ALT, hepatic triglycerides, histopathology, lipid peroxidation, activation of NF-kappaB, expression of NF-kappaB-regulated genes and macrophage chemokines were measured. After 10 days of MCD dietary feeding, gp91phox-/- and wt mice displayed equivalent hepatocellular injury. After 8 weeks, there were fewer activated macrophages in livers of gp91phox-/- mice than controls, despite similar mRNA levels for MCP and MIP chemokines, but fibrosis was similar. NF-kappaB activation and increased expression of ICAM-1, TNF-alpha and COX-2 mRNA were evident in both genotypes, but in gp91phox-/- mice, expression of these genes was confined to hepatocytes. A functional NADPH oxidase complex does not contribute importantly to oxidative stress in this model and therefore is not obligatory for induction or perpetuation of dietary steatohepatitis.

Optofluidic lens actuated by laser-induced solutocapillary forces

Science.gov (United States)

Malyuk, A. Yu.; Ivanova, N. A.

2017-06-01

We demonstrate an adaptive liquid lens controlled by laser-induced solutocapillary forces. The liquid droplet serving as a lens is formed in a thin layer of binary liquid mixture by surface tension driven flows caused by the thermal action of laser irradiation. The shape of droplet, its aperture and the focal length are reversibly changed without hysteresis by varying the intensity of the laser beam. The focal length variation range of the droplet-lens lies in between infinity (a flat layer) to 15 mm (a curved interface). The droplet-lens is capable to adjust the in-plane lateral position in response to a displacement of the laser beam. The proposed laser controlled droplet-lens will enable to develop smart liquid optical devices, which can imitate the accommodation reflex and pupillary light reflex of the eye.

The Sloan Lens ACS Survey. I. A large spectroscopically selected sample of massive early-type lens galaxies

NARCIS (Netherlands)

Bolton, AS; Burles, S; Koopmans, LVE; Treu, T; Moustakas, LA

2006-01-01

The Sloan Lens ACS (SLACS) Survey is an efficient Hubble Space Telescope (HST) Snapshot imaging survey for new galaxy-scale strong gravitational lenses. The targeted lens candidates are selected spectroscopically from the Sloan Digital Sky Survey (SDSS) database of galaxy spectra for having multiple

EDEL: ENEA dosemeter for eye lens

International Nuclear Information System (INIS)

Ferrari, Paolo; Mariotti, Francesca; Campani, Lorenzo

2016-01-01

Since the publication of International Commission on Radiological Protection statement in 2011 on tissue reaction, eye lens radiation protection played an important role in exposed personnel dosimetry. For this reason, the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA) Individual Monitoring Service decided to study a prototype to fulfil specific requests (e.g. for survey in interventional department and intercomparisons). On the basis of such preliminary investigation, a new eye lens dosemeter was developed. The new dosemeter, named EDEL (ENEA Dosemeter for Eye Lens), was characterised in terms of H p (3), the operational quantity related to eye lens monitoring. The investigation was performed experimentally and optimised using the Monte Carlo MCNP6 code. The new prototype was thought to fulfil two main requests: the reliability of the dosimetric data and the portability of the dosemeter itself. The new dosemeter will soon be supplied to the collaborating hospitals for workplace test measurements. (authors)

Gravitational lens effect and pregalactic halo objects

International Nuclear Information System (INIS)

Bontz, R.J.

1979-01-01

The changes in flux, position, and size of a distant extended (galaxy, etc.) source that result from the gravitational lens action of a massive opaque object are discussed. The flux increase is described by a single function of two parameters. One of these parameters characterizes the strength of the gravitational lens, the other describes the alignment of source and lens object. This function also describes the relative intensity of the images formed by lens. ( A similar formalism is discussed by Bourassa et al. for a point source). The formalism is applied to the problem of the galactic halo. It appears that a massive (10 1 2 M/sub sun/) spherical halo surrounding the visible part of the galaxy is consistent with the observable properties of extragalactic sources

Tinting of intraocular lens implants

International Nuclear Information System (INIS)

Zigman, S.

1982-01-01

Intraocular lens (IOL) implants of polymethyl methacrylate (PMMA) lack an important yellow pigment useful as a filter in the visual process and in the protection of the retina from short-wavelength radiant energy. The ability to produce a yellow pigment in the PMMA used in IOL implants by exposure to near-ultraviolet (UV) light was tested. It was found that the highly cross-linked material in Copeland lens blanks was tinted slightly because of this exposure. The absorptive properties of lens blanks treated with near-UV light in this way approached that of the absorptive properties of human lenses. This finding shows that it is possible to alter IOL implants simply so as to induce a pale-yellow pigment in them to improve the visual process and to protect the retinas of IOL users

Tinting of intraocular lens implants

Energy Technology Data Exchange (ETDEWEB)

Zigman, S.

1982-06-01

Intraocular lens (IOL) implants of polymethyl methacrylate (PMMA) lack an important yellow pigment useful as a filter in the visual process and in the protection of the retina from short-wavelength radiant energy. The ability to produce a yellow pigment in the PMMA used in IOL implants by exposure to near-ultraviolet (UV) light was tested. It was found that the highly cross-linked material in Copeland lens blanks was tinted slightly because of this exposure. The absorptive properties of lens blanks treated with near-UV light in this way approached that of the absorptive properties of human lenses. This finding shows that it is possible to alter IOL implants simply so as to induce a pale-yellow pigment in them to improve the visual process and to protect the retinas of IOL users.

Role of Ser-257 in the sliding mechanism of NADP(H) in the reaction catalyzed by the Aspergillus fumigatus flavin-dependent ornithine N5-monooxygenase SidA.

Science.gov (United States)

Shirey, Carolyn; Badieyan, Somayesadat; Sobrado, Pablo

2013-11-08

SidA (siderophore A) is a flavin-dependent N-hydroxylating monooxygenase that is essential for virulence in Aspergillus fumigatus. SidA catalyzes the NADPH- and oxygen-dependent formation of N(5)-hydroxyornithine. In this reaction, NADPH reduces the flavin, and the resulting NADP(+) is the last product to be released. The presence of NADP(+) is essential for activity, as it is required for stabilization of the C4a-hydroperoxyflavin, which is the hydroxylating species. As part of our efforts to determine the molecular details of the role of NADP(H) in catalysis, we targeted Ser-257 for site-directed mutagenesis and performed extensive characterization of the S257A enzyme. Using a combination of steady-state and stopped-flow kinetic experiments, substrate analogs, and primary kinetic isotope effects, we show that the interaction between Ser-257 and NADP(H) is essential for stabilization of the C4a-hydroperoxyflavin. Molecular dynamics simulation results suggest that Ser-257 functions as a pivot point, allowing the nicotinamide of NADP(+) to slide into position for stabilization of the C4a-hydroperoxyflavin.

The effect of orexin-A on cardiac dysfunction mediated by NADPH oxidase-derived superoxide anion in ventrolateral medulla.

Directory of Open Access Journals (Sweden)

Jun Chen

Full Text Available Hypocretin/orexin-producing neurons, located in the perifornical region of the lateral hypothalamus area (LHA and projecting to the brain sites of rostral ventrolateral medulla (RVLM, involve in the increase of sympathetic activity, thereby regulating cardiovascular function. The current study was designed to test the hypothesis that the central orexin-A (OXA could be involved in the cardiovascular dysfunction of acute myocardial infarction (AMI by releasing NAD(PH oxidase-derived superoxide anion (O2 (- generation in RVLM, AMI rat model established by ligating the left anterior descending (LAD coronary artery to induce manifestation of cardiac dysfunction, monitored by the indicators as heart rate (HR, heart rate variability (HRV, mean arterial pressure (MAP and left intraventricular pressure. The results showed that the expressions of OXA in LHA and orexin 1 receptor (OX1R increased in RVLM of AMI rats. The double immunofluorescent staining indicated that OX1R positive cells and NAD(PH oxidative subunit gp91phox or p47phox-immunoreactive (IR cells were co-localized in RVLM. Microinjection of OXA into the cerebral ventricle significantly increased O2 (- production and mRNA expression of NAD(PH oxidase subunits when compared with aCSF-treated ones. Exogenous OXA administration in RVLM produced pressor and tachycardiac effects. Furthermore, the antagonist of OX1R and OX2R (SB-408124 and TCS OX2 29, respectively or apocynin (APO, an inhibitor of NAD(PH oxidase, partly abolished those cardiovascular responses of OXA. HRV power spectral analysis showed that exogenous OXA led to decreased HF component of HRV and increased LF/HF ratio in comparison with aCSF, which suggested that OXA might be related to sympathovagal imbalance. As indicated by the results, OXA might participate in the central regulation of cardiovascular activities by disturbing the sympathovagal balance in AMI, which could be explained by the possibility that OXR and NAD(PH-derived O

Acid phosphatase and lipid peroxidation in human cataractous lens epithelium

Directory of Open Access Journals (Sweden)

Vasavada Abhay

1993-01-01

Full Text Available The anterior lens epithelial cells undergo a variety of degenerative and proliferative changes during cataract formation. Acid phosphatase is primarily responsible for tissue regeneration and tissue repair. The lipid hydroperoxides that are obtained by lipid peroxidation of polysaturated or unsaturated fatty acids bring about deterioration of biological membranes at cellular and tissue levels. Acid phosphatase and lipid peroxidation activities were studied on the lens epithelial cells of nuclear cataract, posterior subcapsular cataract, mature cataract, and mixed cataract. Of these, mature cataractous lens epithelium showed maximum activity for acid phosphatase (516.83 moles of p-nitrophenol released/g lens epithelium and maximum levels of lipid peroxidation (86.29 O.D./min/g lens epithelium. In contrast, mixed cataractous lens epithelium showed minimum activity of acid phosphatase (222.61 moles of p-nitrophenol released/g lens epithelium and minimum levels of lipid peroxidation (54.23 O.D./min/g lens epithelium. From our study, we correlated the maximum activity of acid phosphatase in mature cataractous lens epithelium with the increased areas of superimposed cells associated with the formation of mature cataract. Likewise, the maximum levels of lipid peroxidation in mature cataractous lens epithelium was correlated with increased permeability of the plasma membrane. Conversely, the minimum levels of lipid peroxidation in mixed cataractous lens epithelium makes us presume that factors other than lipid peroxidation may also account for the formation of mixed type of cataract.

The partial coherence modulation transfer function in testing lithography lens

Science.gov (United States)

Huang, Jiun-Woei

2018-03-01

Due to the lithography demanding high performance in projection of semiconductor mask to wafer, the lens has to be almost free in spherical and coma aberration, thus, in situ optical testing for diagnosis of lens performance has to be established to verify the performance and to provide the suggesting for further improvement of the lens, before the lens has been build and integrated with light source. The measurement of modulation transfer function of critical dimension (CD) is main performance parameter to evaluate the line width of semiconductor platform fabricating ability for the smallest line width of producing tiny integrated circuits. Although the modulation transfer function (MTF) has been popularly used to evaluation the optical system, but in lithography, the contrast of each line-pair is in one dimension or two dimensions, analytically, while the lens stand along in the test bench integrated with the light source coherent or near coherent for the small dimension near the optical diffraction limit, the MTF is not only contributed by the lens, also by illumination of platform. In the study, the partial coherence modulation transfer function (PCMTF) for testing a lithography lens is suggested by measuring MTF in the high spatial frequency of in situ lithography lens, blended with the illumination of partial and in coherent light source. PCMTF can be one of measurement to evaluate the imperfect lens of lithography lens for further improvement in lens performance.

Intraocular Lens Calcification; a Clinicopathologic Report

Directory of Open Access Journals (Sweden)

Mozhgan Rezaei-Kanavi

2009-04-01

Full Text Available

PURPOSE: To describe the clinical and pathological features of a case of hydrogel intraocular lens (IOL calcification. CASE REPORT: A 48-year-old man underwent explantation of a single-piece hydrophilic acrylic intraocular lens in his left eye because of decreased visual acuity and milky white opalescence of the IOL. The opacified lens was exchanged uneventfully with a hydrophobic acrylic IOL. Gross examination of the explanted IOL disclosed opacification of the optic and haptics. Full-thickness sections of the lens optic were stained with hematoxylin and eosin (H&E, von Kossa and Gram Tworts'. Microscopic examination of the sections revealed fine and diffuse basophilic granular deposits of variable size within the lens optic parallel to the lens curvature but separated from the surface by a moderately clear zone. The deposits were of high calcium content as evident by dark brown staining with von Kossa. Gram Tworts' staining disclosed no microorganisms. CONCLUSION: This report further contributes to the existing literature on hydrogel IOL calcification.

Cloning, purification, crystallization and preliminary X-ray analysis of a chimeric NADPH-cytochrome P450 reductase

International Nuclear Information System (INIS)

Aigrain, Louise; Pompon, Denis; Truan, Gilles; Moréra, Solange

2009-01-01

A 2.5 Å resolution data set was collected from a crystal of a soluble chimeric form of NADPH-cytochrome P450 reductase (CPR) produced using a fusion gene composed of the yeast FMN and the human FAD domains. The chimeric protein was crystallized in a modified conformation compared with the previously solved structures. NADPH-cytochrome P450 reductase (CPR) is the favoured redox partner of microsomal cytochromes P450. This protein is composed of two flavin-containing domains (FMN and FAD) connected by a structured linker. An active CPR chimera consisting of the yeast FMN and human FAD domains has been produced, purified and crystallized. The crystals belonged to the monoclinic space group C2 and contained one molecule per asymmetric unit. Molecular replacement was performed using the published rat and yeast structures as search models. The initial electron-density maps revealed that the chimeric enzyme had crystallized in a conformation that differed from those of previously solved structures

Contact lens rehabilitation following repaired corneal perforations

Science.gov (United States)

Titiyal, Jeewan S; Sinha, Rajesh; Sharma, Namrata; Sreenivas, V; Vajpayee, Rasik B

2006-01-01

Background Visual outcome following repair of post-traumatic corneal perforation may not be optimal due to presence of irregular keratometric astigmatism. We performed a study to evaluate and compare rigid gas permeable contact lens and spectacles in visual rehabilitation following perforating corneal injuries. Method Eyes that had undergone repair for corneal perforating injuries with or without lens aspiration were fitted rigid gas permeable contact lenses. The fitting pattern and the improvement in visual acuity by contact lens over spectacle correction were noted. Results Forty eyes of 40 patients that had undergone surgical repair of posttraumatic corneal perforations were fitted rigid gas permeable contact lenses for visual rehabilitation. Twenty-four eyes (60%) required aphakic contact lenses. The best corrected visual acuity (BCVA) of ≥ 6/18 in the snellen's acuity chart was seen in 10 (25%) eyes with spectacle correction and 37 (92.5%) eyes with the use of contact lens (p < 0.001). The best-corrected visual acuity with spectacles was 0.20 ± 0.13 while the same with contact lens was 0.58 ± 0.26. All the patients showed an improvement of ≥ 2 lines over spectacles in the snellen's acuity chart with contact lens. Conclusion Rigid gas permeable contact lenses are better means of rehabilitation in eyes that have an irregular cornea due to scars caused by perforating corneal injuries. PMID:16536877

Effect of contact lens use on Computer Vision Syndrome.

Science.gov (United States)

Tauste, Ana; Ronda, Elena; Molina, María-José; Seguí, Mar

2016-03-01

To analyse the relationship between Computer Vision Syndrome (CVS) in computer workers and contact lens use, according to lens materials. Cross-sectional study. The study included 426 civil-service office workers, of whom 22% were contact lens wearers. Workers completed the Computer Vision Syndrome Questionnaire (CVS-Q) and provided information on their contact lenses and exposure to video display terminals (VDT) at work. CVS was defined as a CVS-Q score of 6 or more. The covariates were age and sex. Logistic regression was used to calculate the association (crude and adjusted for age and sex) between CVS and individual and work-related factors, and between CVS and contact lens type. Contact lens wearers are more likely to suffer CVS than non-lens wearers, with a prevalence of 65% vs 50%. Workers who wear contact lenses and are exposed to the computer for more than 6 h day(-1) are more likely to suffer CVS than non-lens wearers working at the computer for the same amount of time (aOR = 4.85; 95% CI, 1.25-18.80; p = 0.02). Regular contact lens use increases CVS after 6 h of computer work. © 2016 The Authors Ophthalmic & Physiological Optics © 2016 The College of Optometrists.

The effect of compliance on contact lens case contamination.

Science.gov (United States)

Tilia, Daniel; Lazon de la Jara, Percy; Zhu, Hua; Naduvilath, Thomas J; Holden, Brien A

2014-03-01

To determine the efficacy of written instructions on contact lens case hygiene and to quantify the effect of noncompliance on contact lens case contamination. Data were retrospectively analyzed from 16 prospective, 3-month daily-wear studies during which six commercially available silicone hydrogel contact lenses and seven lens care solutions (LCS) were tested following a similar protocol. Verbal instructions regarding case hygiene (rinse case with LCS, not tap water) were given in nine studies, while the same instructions were given verbally and in written format in seven studies. A survey on contact lens, LCS, and lens case hygiene was completed at 1- and 3-month visits and compliance with case hygiene instructions was determined. Regular contact lens cases were used for 1 month and collected for microbial analysis at the 1- and 3-month visits. The rate of case contamination and the types of microbes contaminating cases were evaluated. Participants given verbal and written instructions were more likely to be compliant with case hygiene instructions than those just given verbal instructions (odds ratio [OR]: 2.19, p hygiene can be improved by effective communication of instructions. Contact lens wearers should be actively discouraged from rinsing contact lens cases with tap water because of the increased risk of GNB contamination.

Lens dislocation has a possible relationship with laser iridotomy

Directory of Open Access Journals (Sweden)

Mutoh T

2012-12-01

Full Text Available Tetsuya Mutoh,1,2 Kevin F Barrette,2 Yukihiro Matsumoto,1 Makoto Chikuda11Department of Ophthalmology, Dokkyo Medical University Koshigaya Hospital, Koshigaya City, Saitama, Japan; 2Department of Ophthalmology, Boston University School of Medicine, Boston, MA, USAAbstract: We report our recent experience of four eyes with spontaneous lens dislocation in four patients with no history of trauma or any systemic disease associated with zonular dialysis. Lens dislocation developed with 0.5 to 6 months following laser iridotomy. All patients were male and two eyes were complicated with acute primary angle closure glaucoma preoperatively. Case 1 showed bilateral lens dislocation, while cases 2 and 3 involved unilateral lens dislocation. Cases 2 and 3 showed lenses completely dislocated into the vitreous cavity. All cases needed lens removal and scleral fixation of intraocular lenses. Final visual acuity was 1.2 in all cases. We suspect that laser iridotomy may induce localized zonular dialysis that results in progressive zonular weakness, leading to lens dislocation.Keywords: lens dislocation, laser iridotomy, primary angle closure glaucoma

Surgical effect of traumatic lens dislocation with secondary glaucoma

Directory of Open Access Journals (Sweden)

Xiao-Dan Zhang

2014-10-01

Full Text Available AIM: To retrospectively evaluate the effect of lens extraction combined with vitrectomy to treat traumatic lens dislocation with secondary glaucoma.METHODS:Thirty-one eyes(31 casesof lens dislocation caused by blunt trauma with secondary glaucoma were treated respectively with cataract extraction combined with anterior vitrectomy, trabeculectomy and intraocular lens implantation. The visual acuity and pressure were observed 1wk, 1 and 3mo after operative. RESULTS:Thirty-one eyes were all complete the operation successfully, and 6 eyes were given combined trabeculectomy, 9 eyes were implanted anterior chamber intraocular lens implantation(IOLand 15 eyes were given posterior chamber suture fixation. Sixteen eyes were implanted in one-stage operation, while 8 eyes were implanted in two-stage operation. All intraocular pressure(IOPwere controlled to the normal level after operation and 23 eyes had visual acuity of more than 0.3.CONCLUSION:Lens extraction combined with vitrectomy is an effective method for treatment of lens dislocation with secondary glaucoma. In order to control the IOP and get well visual function, we should choose IOL implantation or trabeculectomy according to the patient's condition.

Lens transmission measurement for an absolute radiation thermometer

International Nuclear Information System (INIS)

Hao, X.; Yuan, Z.; Lu, X.

2013-01-01

The lens transmission for the National Institute of Metrology of China absolute radiation thermometer is measured by a hybrid method. The results of the lens transmission measurements are 99.002% and 86.792% for filter radiometers with center wavelengths 633 nm and 900 nm, respectively. These results, after correcting for diffraction factors and the size-of-source effect when the lens is incorporated within the radiometer, can be used for measurement of thermodynamic temperature. The expanded uncertainty of the lens transmission measurement system has been evaluated. It is 1.3×10 −3 at 633 nm and 900 nm, respectively

Chemical performance of multi-environment trials in lens (Lens culinaris M.).

Science.gov (United States)

Karadavut, Ufuk; Palta, Cetin

2010-01-15

Genotype-environment (GE) interaction has been a major effect to determine stable lens (Lens culinaris (Medik.) Merr.) cultivars for chemical composition in Turkey. Utilization of the lines depends on their agronomic traits and stability of the chemical composition in diverse environments. The objectives of this study were: (i) to evaluate the influence of year and location on the chemical composition of lens genotypes; and (ii) to determine which cultivar is the most stable. Genotypes were evaluated over 3 years (2005, 2006 and 2007) at four locations in Turkey. Effects of year had the largest impact on all protein contents. GE interaction was analyzed by using linear regression techniques. Stability was estimated using the Eberhart and Russell method. 'Kişlik Kirmizi51' was the most stable cultivar for grain yield. The highest protein was obtained from 'Kişlik Kirmizi51' (4.6%) across environments. According to stability analysis, 'Firat 87' had the most stable chemical composition. This genotype had a regression coefficient (b(i) = 1) around unity, and deviations from regression values (delta(ij) = 0) around zero. Chemical composition was affected by year in this study. Temperature might have an effect on protein, oil, carbohydrate, fibre and ash. Firat 87 could be recommended for favourable environments. Copyright (c) 2009 Society of Chemical Industry.

Accelerating convergence in automatic lens design

International Nuclear Information System (INIS)

Brixner, B.

1981-01-01

Among the various factors that slow lens optimization-insufficient performance targets, the absence of a unique solution, false local minima, a poorly scaled change vector, failure to find the optimum damping number, and failure to equalize the parameter gradients-the importance of parameter gradient equalization has been insufficiently recognized. Gradients can be approximately equalized by scaling the lens to a suitable size while it is being optimized. For best results, the size of the damping number should also be optimized during each iteration. If these two procedures are followed, scaling the change vector is usually not crucial. To illustrate the importance of parameter equalization, a lens optimization is analyzed

Nuclear magnetic resonance studies of lens transparency

International Nuclear Information System (INIS)

Beaulieu, C.F.

1989-01-01

Transparency of normal lens cytoplasm and loss of transparency in cataract were studied by nuclear magnetic resonance (NMR) methods. Phosphorus ( 31 P) NMR spectroscopy was used to measure the 31 P constituents and pH of calf lens cortical and nuclear homogenates and intact lenses as a function of time after lens enucleation and in opacification produced by calcium. Transparency was measured with laser spectroscopy. Despite complete loss of adenosine triphosphate (ATP) within 18 hrs of enucleation, the homogenates and lenses remained 100% transparent. Additions of calcium to ATP-depleted cortical homogenates produced opacification as well as concentration-dependent changes in inorganic phosphate, sugar phosphates, glycerol phosphorylcholine and pH. 1 H relaxation measurements of lens water at 200 MHz proton Larmor frequency studied temperature-dependent phase separation of lens nuclear homogenates. Preliminary measurements of T 1 and T 2 with non-equilibrium temperature changes showed a change in the slope of the temperature dependence of T 1 and T 2 at the phase separation temperature. Subsequent studies with equilibrium temperature changes showed no effect of phase separation on T 1 or T 2 , consistent with the phase separation being a low-energy process. 1 H nuclear magnetic relaxation dispersion (NMRD) studies (measurements of the magnetic field dependence of the water proton 1/T 1 relaxation rates) were performed on (1) calf lens nuclear and cortical homogenates (2) chicken lens homogenates, (3) native and heat-denatured egg white and (4) pure proteins including bovine γ-II crystallin bovine serum albumin (BSA) and myoglobin. The NMRD profiles of all samples exhibited decreases in 1/T 1 with increasing magnetic field

Lubricant effects on low Dk and silicone hydrogel lens comfort.

Science.gov (United States)

Ozkan, Jerome; Papas, Eric

2008-08-01

To investigate the influence of three lubricants of varying viscosity, on postinsertion and 6 h comfort with contact lens wear. Comfort and associated symptoms of dryness were assessed in 15 experienced contact lens wearers. Subjects wore a low Dk lens in one eye and a silicone hydrogel in the other and participated in four separate trials involving no lubricant (baseline), saline, and two commercially available lubricants of differing viscosity. The in-eye lubricants were used immediately following lens insertion and every 2 h postinsertion for a 6 h wear period. Postlens insertion comfort was significantly better for both lens types when lubricants or saline were used compared with no lubricant use. After 6 h lens wear, comfort was influenced by lens type and not by in-eye lubricant or saline use. Also after 6 h lens wear, less dryness sensation was reported for silicone hydrogel lenses when using lubricants but not saline. Although lubricant use does help reduce dryness symptoms with silicone hydrogel lens wear, there appears to be minimal longer-term benefit to comfort. Furthermore, increased lubricant viscosity did not lead to improved longer-term comfort.

Composite modified Luneburg model of human eye lens.

Science.gov (United States)

Gómez-Correa, J E; Balderas-Mata, S E; Pierscionek, B K; Chávez-Cerda, S

2015-09-01

A new lens model based on the gradient-index Luneburg lens and composed of two oblate half spheroids of different curvatures is presented. The spherically symmetric Luneburg lens is modified to create continuous isoindicial contours and to incorporate curvatures that are similar to those found in a human lens. The imaging capabilities of the model and the changes in the gradient index profile are tested for five object distances, for a fixed geometry and for a fixed image distance. The central refractive index decreases with decreasing object distance. This indicates that in order to focus at the same image distance as is required in the eye, a decrease in refractive power is needed for rays from closer objects that meet the lens surface at steeper angles compared to rays from more distant objects. This ensures a highly focused image with no spherical aberration.

Focusing properties of a square electrostatic rainbow lens

International Nuclear Information System (INIS)

Telečki, I.; Petrović, S.; Beličev, P.; Rađenović, B.; Balvanović, R.; Bojović, B.; Nešković, N.

2012-01-01

This paper is devoted to the focusing properties of a square electrostatic rainbow lens, which is a novel ion beam optical element. We consider the transmission of parallel and non-parallel proton beams of the initial kinetic energy of 10 keV through this lens. The potential of the electrodes of the lens is chosen to be 2 kV. The electrostatic potential and components of the electric field in the region of the lens are calculated using a three-dimensional finite element computer code. We investigate the spatial and angular distributions of protons propagating through the lens and in the drift space after it. It is confirmed that the evolutions of these distributions are determined by the evolutions of the corresponding rainbow lines, generated using the theory of crystal rainbows. The beam is separated into two components. One beam component, appearing as a beam core, is generated dominantly by the focused protons. Its boundary line in the transverse position plane can be very well approximated by a hypotrochoid. The other beam component is generated dominantly by the defocused protons. We present the focusing coefficient of the lens, the confining coefficients of the lens for the focused and defocused protons, the density of the beam core, the vertical or horizontal emittance of the beam core, and the brightness of the beam core.

Lens Model

DEFF Research Database (Denmark)

Nash, Ulrik William

2014-01-01

Firms consist of people who make decisions to achieve goals. How do these people develop the expectations which underpin the choices they make? The lens model provides one answer to this question. It was developed by cognitive psychologist Egon Brunswik (1952) to illustrate his theory of probabil...

TESS Lens-Bezel Assembly Modal Testing

Science.gov (United States)

Dilworth, Brandon J.; Karlicek, Alexandra

2017-01-01

The Transiting Exoplanet Survey Satellite (TESS) program, led by the Kavli Institute for Astrophysics and Space Research at the Massachusetts Institute of Technology (MIT) will be the first-ever spaceborne all-sky transit survey. MIT Lincoln Laboratory is responsible for the cameras, including the lens assemblies, detector assemblies, lens hoods, and camera mounts. TESS is scheduled to be launched in August of 2017 with the primary goal to detect small planets with bright host starts in the solar neighborhood, so that detailed characterizations of the planets and their atmospheres can be performed. The TESS payload consists of four identical cameras and a data handling unit. Each camera consists of a lens assembly with seven optical elements and a detector assembly with four charge-coupled devices (CCDs) including their associated electronics. The optical prescription requires that several of the lenses are in close proximity to a neighboring element. A finite element model (FEM) was developed to estimate the relative deflections between each lens-bezel assembly under launch loads to predict that there are adequate clearances preventing the lenses from making contact. Modal tests using non-contact response measurements were conducted to experimentally estimate the modal parameters of the lens-bezel assembly, and used to validate the initial FEM assumptions. Key Words Non-contact measurements, modal analysis, model validation

Surface Fourier-transform lens using a metasurface

International Nuclear Information System (INIS)

Li, Yun Bo; Cai, Ben Geng; Cheng, Qiang; Cui, Tie Jun

2015-01-01

We propose a surface (or 2D) Fourier-transform lens using a gradient refractive index (GRIN) metasurface in the microwave band, which is composed of sub-wavelength quasi-periodical metallic patches on a grounded dielectric substrate. Such a metasurface supports the transverse magnetic (TM) modes of surface waves. To gradually change the size of textures, we obtain different surface refractive indices, which can be tailored to fit the required refractive-index profile of a surface Fourier-transform lens. According to the theory of spatial Fourier transformation, we make use of the proposed lens to realize surface plane-wave scanning under different feeding locations. The simulation and experimental results jointly confirm the validity of the surface Fourier-transform lens. The proposed method can also be extended to the terahertz frequency. (paper)

The Correlation between Daily Lens Wear Duration and Dry Eye Syndrome.

Science.gov (United States)

Lubis, Rodiah Rahmawaty; Gultom, Monica Tumiar Hanna

2018-05-20

To analyze the correlation between the daily lens wear duration and dry eye syndrome. This study was an analytic cross sectional study using consecutive sampling conducted among the students in Economy and Bussiness Faculty and Faculty of Humanities in University of Sumatera Utara aged between 17 to 23 that wore contact lens continously for at least a year and 5 days a week. The symptoms were assessed using Contact Lens Dry Eye Questionnaire-8 (CLDEQ-8) and interview about their contact lens comfort; eye drops usage, contact lens washing habit, daily circumstances, places to buy contact lens and personal experince in wearing contact lens. The questionnaire was completed by 53 students. All of them were female and wore softlens wearers. The mean duration of daily wear was 8.19 ± 2.20 hours. The most common symptom experienced was dry eye and the least symptom experienced was removing lens. The most frequent symptom experienced was closing eyes and the least frequent symptom experienced was removing lenses. This study used Exact Test as analysis statistic method. The result was p > 0.05 which means there is no correlation between daily lens wear duration and dry eye syndrome. This study showed that dry eye syndrome was not correlated with daily lens wear duration, but affected by many factors such as contact lens, lens care solution, eye drops usage and environment.

Measuring and correcting aberrations of a cathode objective lens

International Nuclear Information System (INIS)

Tromp, R.M.

2011-01-01

In this paper I discuss several theoretical and practical aspects related to measuring and correcting the chromatic and spherical aberrations of a cathode objective lens as used in Low Energy Electron Microscopy (LEEM) and Photo Electron Emission Microscopy (PEEM) experiments. Special attention is paid to the various components of the cathode objective lens as they contribute to chromatic and spherical aberrations, and affect practical methods for aberration correction. This analysis has enabled us to correct a LEEM instrument for the spherical and chromatic aberrations of the objective lens. -- Research highlights: → Presents a comprehensive theory of the relation between chromatic aberration and lens current in a cathode objective lens. → Presents practical methods for measuring both spherical and chromatic aberrations of a cathode objective lens. → Presents measurements of these aberrations in good agreement with theory. → Presents practical methods for measuring and correcting these aberrations with an electron mirror.

Gravitational-Like Lens Based on Graphene Ripple.

Science.gov (United States)

Liu, Daqing; Chen, Shuyue; Ma, Ning; Zhao, Xiang; Xu, Zhuo

2015-10-01

We conducted a semiclassical study on carrier movement in curved graphene. A previous attempt was made to show that curved graphene is a readily available and cheap laboratory material used to study general relativity effects, especially if the electron energies satisfy 4μeV ≪ |E| ≪ 3eV. Furthermore, a gravitational-like lens can be constructed based on a special graphene ripple; this lens has neither chromatic nor cometic aberration. One can design an ideal electron lens using a graphene ripple.

Gabor lens focusing of a negative ion beam

International Nuclear Information System (INIS)

Palkovic, J.A.; Mills, F.E.; Schmidt, C.; Young, D.E.

1989-05-01

Gabor or plasma lenses have previously been used to focus intense beams of positive ions at energies from 10 keV to 5 MeV. It is the large electrostatic field of the non-neutral plasma in the Gabor lens which is responsible for the focusing. Focusing an ion beam with a given sign of charge in a Gabor lens requires a non-neutral plasma with the opposite sign of charge as the beam. A Gabor lens constructed at Fermilab has been used to focus a 30 keV proton beam with good optical quality. We discuss studies of the action of a Gabor lens on a beam of negative ions. A Gabor lens has been considered for matching an H/sup /minus// beam into an RFQ in the redesign of the low energy section of the Fermilab linac. 9 refs., 3 figs., 1 tab

Daily disposable contact lens prescribing around the world.

Science.gov (United States)

Efron, Nathan; Morgan, Philip B; Helland, Magne; Itoi, Motozumi; Jones, Deborah; Nichols, Jason J; van der Worp, Eef; Woods, Craig A

2010-10-01

Daily disposable contact lenses were introduced into the market 16 years ago. Data that we have gathered from annual contact lens fitting surveys conducted in Australia, Canada, Japan, The Netherlands, Norway, the UK and the USA between 2000 and 2008 indicates an overall increase in daily disposable lens fitting during this period. Daily disposable lenses are especially popular in Japan, Norway and the UK. There is a trend for these lenses to be fitted on a part-time basis. Males are over-represented in daily disposable lens fitting-a trend that is especially evident in Canada. Daily disposable lens wearers are about two years younger than wearers of reusable lenses in Japan and The Netherlands. The convenience and health benefits of daily disposable lenses are expected to fuel continued growth in this sector. Copyright (c) 2010 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Comparative molecular modeling study of Arabidopsis NADPH-dependent thioredoxin reductase and its hybrid protein.

Directory of Open Access Journals (Sweden)

Yuno Lee

Full Text Available 2-Cys peroxiredoxins (Prxs play important roles in the protection of chloroplast proteins from oxidative damage. Arabidopsis NADPH-dependent thioredoxin reductase isotype C (AtNTRC was identified as efficient electron donor for chloroplastic 2-Cys Prx-A. There are three isotypes (A, B, and C of thioredoxin reductase (TrxR in Arabidopsis. AtNTRA contains only TrxR domain, but AtNTRC consists of N-terminal TrxR and C-terminal thioredoxin (Trx domains. AtNTRC has various oligomer structures, and Trx domain is important for chaperone activity. Our previous experimental study has reported that the hybrid protein (AtNTRA-(Trx-D, which was a fusion of AtNTRA and Trx domain from AtNTRC, has formed variety of structures and shown strong chaperone activity. But, electron transfer mechanism was not detected at all. To find out the reason of this problem with structural basis, we performed two different molecular dynamics (MD simulations on AtNTRC and AtNTRA-(Trx-D proteins with same cofactors such as NADPH and flavin adenine dinucleotide (FAD for 50 ns. Structural difference has found from superimposition of two structures that were taken relatively close to average structure. The main reason that AtNTRA-(Trx-D cannot transfer the electron from TrxR domain to Trx domain is due to the difference of key catalytic residues in active site. The long distance between TrxR C153 and disulfide bond of Trx C387-C390 has been observed in AtNTRA-(Trx-D because of following reasons: i unstable and unfavorable interaction of the linker region, ii shifted Trx domain, and iii different or weak interface interaction of Trx domains. This study is one of the good examples for understanding the relationship between structure formation and reaction activity in hybrid protein. In addition, this study would be helpful for further study on the mechanism of electron transfer reaction in NADPH-dependent thioredoxin reductase proteins.

NADPH oxidase/ROS-dependent PYK2 activation is involved in TNF-α-induced matrix metalloproteinase-9 expression in rat heart-derived H9c2 cells

International Nuclear Information System (INIS)

Yang, Chuen-Mao; Lee, I-Ta; Hsu, Ru-Chun; Chi, Pei-Ling; Hsiao, Li-Der

2013-01-01

TNF-α plays a mediator role in the pathogenesis of chronic heart failure contributing to cardiac remodeling and peripheral vascular disturbances. The implication of TNF-α in inflammatory responses has been shown to be mediated through up-regulation of matrix metalloproteinase-9 (MMP-9). However, the detailed mechanisms of TNF-α-induced MMP-9 expression in rat embryonic-heart derived H9c2 cells are largely not defined. We demonstrated that in H9c2 cells, TNF-α induced MMP-9 mRNA and protein expression associated with an increase in the secretion of pro-MMP-9. TNF-α-mediated responses were attenuated by pretreatment with the inhibitor of ROS (N-acetyl-L-cysteine, NAC), NADPH oxidase [apocynin (APO) or diphenyleneiodonium chloride (DPI)], MEK1/2 (U0126), p38 MAPK (SB202190), JNK1/2 (SP600125), NF-κB (Bay11-7082), or PYK2 (PF-431396) and transfection with siRNA of TNFR1, p47 phox , p42, p38, JNK1, p65, or PYK2. Moreover, TNF-α markedly induced NADPH oxidase-derived ROS generation in these cells. TNF-α-enhanced p42/p44 MAPK, p38 MAPK, JNK1/2, and NF-κB (p65) phosphorylation and in vivo binding of p65 to the MMP-9 promoter were inhibited by U0126, SB202190, SP600125, NAC, DPI, or APO. In addition, TNF-α-mediated PYK2 phosphorylation was inhibited by NAC, DPI, or APO. PYK2 inhibition could reduce TNF-α-stimulated MAPKs and NF-κB activation. Thus, in H9c2 cells, we are the first to show that TNF-α-induced MMP-9 expression is mediated through a TNFR1/NADPH oxidase/ROS/PYK2/MAPKs/NF-κB cascade. We demonstrated that NADPH oxidase-derived ROS generation is involved in TNF-α-induced PYK2 activation in these cells. Understanding the regulation of MMP-9 expression and NADPH oxidase activation by TNF-α on H9c2 cells may provide potential therapeutic targets of chronic heart failure. - Highlights: • TNF-α induces MMP-9 secretion and expression via a TNFR1-dependent pathway. • TNF-α induces ROS/PYK2-dependent MMP-9 expression in H9c2 cells. • TNF-α induces

New insights into the roles of NADPH oxidases in sexual development and ascospore germination in Sordaria macrospora.

Science.gov (United States)

Dirschnabel, Daniela Elisabeth; Nowrousian, Minou; Cano-Domínguez, Nallely; Aguirre, Jesus; Teichert, Ines; Kück, Ulrich

2014-03-01

NADPH oxidase (NOX)-derived reactive oxygen species (ROS) act as signaling determinants that induce different cellular processes. To characterize NOX function during fungal development, we utilized the genetically tractable ascomycete Sordaria macrospora. Genome sequencing of a sterile mutant led us to identify the NADPH oxidase encoding nox1 as a gene required for fruiting body formation, regular hyphal growth, and hyphal fusion. These phenotypes are shared by nor1, lacking the NOX regulator NOR1. Further phenotypic analyses revealed a high correlation between increased ROS production and hyphal fusion deficiencies in nox1 and other sterile mutants. A genome-wide transcriptional profiling analysis of mycelia and isolated protoperithecia from wild type and nox1 revealed that nox1 inactivation affects the expression of genes related to cytoskeleton remodeling, hyphal fusion, metabolism, and mitochondrial respiration. Genetic analysis of nox2, lacking the NADPH oxidase 2 gene, nor1, and transcription factor deletion mutant ste12, revealed a strict melanin-dependent ascospore germination defect, indicating a common genetic pathway for these three genes. We report that gsa3, encoding a G-protein α-subunit, and sac1, encoding cAMP-generating adenylate cyclase, act in a separate pathway during the germination process. The finding that cAMP inhibits ascospore germination in a melanin-dependent manner supports a model in which cAMP inhibits NOX2 activity, thus suggesting a link between both pathways. Our results expand the current knowledge on the role of NOX enzymes in fungal development and provide a frame to define upstream and downstream components of the NOX signaling pathways in fungi.

A novel lens epithelium gene, LEP503, is highly conserved in different vertebrate species and is developmentally regulated in postnatal rat lens.

Science.gov (United States)

Wen, Y; Sachs, G; Athmann, C

2000-02-01

The development of the lens is dependent on the proliferation of lens epithelial cells and their differentiation into fiber cells near the lens bow/equator. Identification of genes specifically expressed in the lens epithelial cells and their functions may provide insight into molecular events that regulate the processes of lens epithelial cell differentiation. In this study, a novel lens epithelium gene product, LEP503, identified from rat by a subtractive cDNA cloning strategy was investigated in the genome organization, mRNA expression and protein localization. The genomic sequences for LEP503 isolated from rat, mouse and human span 1754 bp, 1694 bp and 1895 bp regions encompassing the 5'-flanking region, two exons, one intron and 3'-flanking region. All exon-intron junction sequences conform to the GT/AG rule. Both mouse and human LEP503 genes show very high identity (93% for mouse and 79% for human) to rat LEP503 gene in the exon 1 that contains an open reading frame coding for a protein of 61 amino acid residues with a leucine-rich domain. The deduced protein sequences also show high identity (91% between mouse and rat and 77% between human and rat). Western blot shows that LEP503 is present as a specific approximately 6.9 kDa band in the water-insoluble-urea-soluble fraction of lens cortex where lens epithelium is included. Immuno-staining shows that LEP503 is localized in the epithelial cells along the entire anterior surface of rat lens. Developmentally, LEP503 is expressed at a low level at newborn, and then the expression level increases by about ten-fold around postnatal day 14 and remains at this high level for about 25 days before it drops back to the low level by postnatal day 84. These data suggest that the LEP503 may be an important lens epithelial cell gene involving the processes of epithelial cell differentiation. Copyright 2000 Academic Press.

A lazy way to design infrared lens

Science.gov (United States)

Qiu, RongSheng; Wu, JianDong; Chen, LongJiang; Yu, Kun; Pang, HaoJun; Hu, BaiZhen

2017-08-01

We designed a compact middle-wave infrared (MWIR) lens with a large focal length ratio (about 1.5:1), used in the 3.7 to 4.8 μm range. The lens is consisted of a compact front group and a re-imaging group. Thanks to the compact front group configuration, it is possible to install a filter wheel mechanism in such a tight space. The total track length of the lens is about 50mm, which includes a 2mm thick protective window and a cold shield of 12mm. The full field of view of the lens is about 3.6°, and F number is less than 1.6, the image circle is about 4.6mm in diameter. The design performance of the lens reaches diffraction limitation, and doesn't change a lot during a temperature range of -40°C +60°C. This essay proposed a stepwise design method of infrared optical system guided by the qualitative approach. The method fully utilize the powerful global optimization ability, with a little effort to write code snippet in optical design software, frees optical engineer from tedious calculation of the original structure.

Virial Expansion Bounds

Science.gov (United States)

Tate, Stephen James

2013-10-01

In the 1960s, the technique of using cluster expansion bounds in order to achieve bounds on the virial expansion was developed by Lebowitz and Penrose (J. Math. Phys. 5:841, 1964) and Ruelle (Statistical Mechanics: Rigorous Results. Benjamin, Elmsford, 1969). This technique is generalised to more recent cluster expansion bounds by Poghosyan and Ueltschi (J. Math. Phys. 50:053509, 2009), which are related to the work of Procacci (J. Stat. Phys. 129:171, 2007) and the tree-graph identity, detailed by Brydges (Phénomènes Critiques, Systèmes Aléatoires, Théories de Jauge. Les Houches 1984, pp. 129-183, 1986). The bounds achieved by Lebowitz and Penrose can also be sharpened by doing the actual optimisation and achieving expressions in terms of the Lambert W-function. The different bound from the cluster expansion shows some improvements for bounds on the convergence of the virial expansion in the case of positive potentials, which are allowed to have a hard core.

Upper bounds on superpartner masses from upper bounds on the Higgs boson mass.

Science.gov (United States)

Cabrera, M E; Casas, J A; Delgado, A

2012-01-13

The LHC is putting bounds on the Higgs boson mass. In this Letter we use those bounds to constrain the minimal supersymmetric standard model (MSSM) parameter space using the fact that, in supersymmetry, the Higgs mass is a function of the masses of sparticles, and therefore an upper bound on the Higgs mass translates into an upper bound for the masses for superpartners. We show that, although current bounds do not constrain the MSSM parameter space from above, once the Higgs mass bound improves big regions of this parameter space will be excluded, putting upper bounds on supersymmetry (SUSY) masses. On the other hand, for the case of split-SUSY we show that, for moderate or large tanβ, the present bounds on the Higgs mass imply that the common mass for scalars cannot be greater than 10(11)  GeV. We show how these bounds will evolve as LHC continues to improve the limits on the Higgs mass.

Contact Lens Related Corneal Ulcer

OpenAIRE

Loh, KY; Agarwal, P

2010-01-01

A corneal ulcer caused by infection is one of the major causes of blindness worldwide. One of the recent health concerns is the increasing incidence of corneal ulcers associated with contact lens user especially if the users fail to follow specific instruction in using their contact lenses. Risk factors associated with increased risk of contact lens related corneal ulcers are: overnight wear, long duration of continuous wear, lower socio-economic classes, smoking, dry eye and poor hygiene. Th...

Hu-Lu-Ba-Wan Attenuates Diabetic Nephropathy in Type 2 Diabetic Rats through PKC-α/NADPH Oxidase Signaling Pathway

Directory of Open Access Journals (Sweden)

Lishan Zhou

2013-01-01

Full Text Available Hu-Lu-Ba-Wan (HLBW is a Chinese herbal prescription used to treat kidney deficiency. The aim of this study was to explore the effect and mechanism of HLBW on diabetic nephropathy (DN in type 2 diabetic rats. The rat model of DN was established by being fed a high-fat diet and intravenous injection of streptozotocin. Then, HLBW decoction was administered for 16 weeks. Blood glucose level, lipid profile, renal function, 24-hour total urinary protein, and albumin content were examined. Renal morphology and superoxide anion levels were evaluated. The activity of nicotinamide-adenine dinucleotide phosphate (NADPH and protein kinase C-alpha (PKC-α related genes expression in renal tissue were also determined. Our data demonstrated that HLBW significantly improved hyperglycemia, hyperlipidemia, and proteinuria in diabetic rats compared with those of control group. HLBW also alleviated glomerular expansion and fibrosis, extracellular matrix accumulation and effacement of the foot processes. Additionally, HLBW reduced superoxide anion level, NADPH oxidase activity, the protein and mRNA expressions of p47phox, and the protein expression of phosphorylated PKC-α in renal tissue. These results suggest that HLBW is effective in the treatment of DN in rats. The underlying mechanism may be related to the attenuation of renal oxidative stress via PKC-α/NADPH oxidase signaling pathway.

Adaptive Lens Inspired by Bio-Visual Systems

National Research Council Canada - National Science Library

Lo, Yu-Hwa

2004-01-01

...: (a) We have identified and demonstrated the merits of PDMS elastomer for lens membranes. The PDMS-based fluidic lens process has been proven to be simple, controllable, and scalable to form lenses from 10 urn to several centimeters in diameter. (b...

Multiocular image sensor with on-chip beam-splitter and inner meta-micro-lens for single-main-lens stereo camera.

Science.gov (United States)

Koyama, Shinzo; Onozawa, Kazutoshi; Tanaka, Keisuke; Saito, Shigeru; Kourkouss, Sahim Mohamed; Kato, Yoshihisa

2016-08-08

We developed multiocular 1/3-inch 2.75-μm-pixel-size 2.1M- pixel image sensors by co-design of both on-chip beam-splitter and 100-nm-width 800-nm-depth patterned inner meta-micro-lens for single-main-lens stereo camera systems. A camera with the multiocular image sensor can capture horizontally one-dimensional light filed by both the on-chip beam-splitter horizontally dividing ray according to incident angle, and the inner meta-micro-lens collecting the divided ray into pixel with small optical loss. Cross-talks between adjacent light field images of a fabricated binocular image sensor and of a quad-ocular image sensor are as low as 6% and 7% respectively. With the selection of two images from one-dimensional light filed images, a selective baseline for stereo vision is realized to view close objects with single-main-lens. In addition, by adding multiple light field images with different ratios, baseline distance can be tuned within an aperture of a main lens. We suggest the electrically selective or tunable baseline stereo vision to reduce 3D fatigue of viewers.

La p67-PHOX como un elemento esencial del sistema NADPH oxidasa de las células fagocíticas

Directory of Open Access Journals (Sweden)

Pablo Javier Patiño Grajales

1999-01-01

Full Text Available Las células fagocíticas cumplen un papel fundamental en la defensa innata del huésped contra la invasión de microorganismos. Luego de ser fagocitados, uno de lo~ mecanismos utilizados para destruir dichos microorganismos es la producción de metabolitos intermedios del oxígeno generados a través del sistema NADPH oxidasa. Los radicales libres del oxígeno están al mismo tiempo involucrados en el daño tisular, que ocurre en muchas condiciones inflamatorias. La NADPH oxidasa es un complejo proteico conformado por varios componentes: gp91-phox y p22-phox, los cuales forman un heterodímero llamado citocromo b5581 que se encuentra en la membrana de las células fagocíticas, y por las proteínas p47-phox, p67-phox y p40-phox que forman un complejo macromolecular localizado en el citoplasma. Durante la activación de las células fagocíticas los componentes citosólicos del sistema se translocan a la membrana y se unen al citocromo b558' conformando así el complejo enzimático activo de la NADPH oxidasa cuya importancia biológica se ha evidenciado en las últimas cuatro décadas gracias al estudio de la enfermedad granulomatosa crónica (EGC. Ésta es una inmunodeficiencia primaria caracterizada por infecciones recurrentes y severas. Todos los casos de EGC reportados hasta ahora tienen que ver con una alteración en los genes que codifican las proteínas gp91-phox, p22-phox, p67-phoxy p47-phox. La p67 -phox es uno de los componentes del sistema NADPH oxidasa que más ha llamado la atención en los últimos años, pues tiene un papel fundamental en la activación del flujo de electrones desde el citoplasma a la vacuola fagocítica. En este articulo se hace una revisión acerca de lo que hasta ahora se conoce de la estructura y función de la p67-phox. Además se revisarán las diversas mutaciones identificadas en su gen, que debido a su alto grado de heterogeneidad son de gran utilidad para el entendimiento de la estructura y función del

Active liquid-crystal deflector and lens with Fresnel structure

Science.gov (United States)

Shibuya, Giichi; Yamano, Shohei; Yoshida, Hiroyuki; Ozaki, Masanori

2017-02-01

A new type of tunable Fresnel deflector and lens composed of liquid crystal was developed. Combined structure of multiple interdigitated electrodes and the high-resistivity (HR) layer implements the saw-tooth distribution of electrical potential with only the planar surfaces of the transparent substrates. According to the numerical calculation and design, experimental devices were manufactured with the liquid crystal (LC) material sealed into the sandwiched flat glass plates of 0.7 mm thickness with rubbed alignment layers set to an anti-parallel configuration. Fabricated beam deflector with no moving parts shows the maximum tilt angle of +/-1.3 deg which can apply for optical image stabilizer (OIS) of micro camera. We also discussed and verified their lens characteristics to be extended more advanced applications. Transparent interdigitated electrodes were concentrically aligned on the lens aperture with the insulator gaps under their boundary area. The diameter of the lens aperture was 30 mm and the total number of Fresnel zone was 100. Phase retardation of the beam wavefront irradiated from the LC lens device can be evaluated by polarizing microscope images with a monochromatic filter. Radial positions of each observed fringe are plotted and fitted with 2nd degree polynomial approximation. The number of appeared fringes is over 600 in whole lens aperture area and the correlation coefficients of all approximations are over 0.993 that seems enough ideal optical wavefront. The obtained maximum lens powers from the approximations are about +/-4 m-1 which was satisfied both convex and concave lens characteristics; and their practical use for the tunable lens grade eyeglasses became more prospective.

A Model of the Effect of Lens Development on Refraction in Schoolchildren.

Science.gov (United States)

He, Ji C

2017-12-01

The study provides a new theory on the mechanism underlying myopia development, and it could be useful in clinical practice to control myopia development in schoolchildren. To model the effect of the crystalline lens on refractive development in schoolchildren. The Zemax 13 was used to calculate Zernike aberrations and refractions across 50° horizontal visual fields. Optical effects of the anterior chamber depth, lens thickness, and radii of curvature of the lens surfaces on refractions were modeled. Refractive changes induced by lens development in emmetropic and myopic eyes, based on a previous longitudinal study from literature, were calculated. A lens thickness reduction with an anterior chamber depth deepening caused a hyperopic shift over the visual fields and even more at the periphery. Opposite effects were found when the lens was thinned without any change of the anterior chamber depth. While a flattening of the anterior lens surface produced hyperopic refractions overall, a posterior lens flattening caused a myopic shift at the periphery, but a hyperopic shift of the central refraction. In the myopic eye, lens development induced refractive change toward more hyperopic over the visual fields and more at the periphery. Lens thinning and lens axial movement participate in peripheral refractive development in schoolchildren, and lens development with a deeper anterior chamber depth and a flatter lens surface in the myopic eye could generate extra hyperopia over visual fields. The myopic lens development could be due to a backward movement of the lens, driven by a backward growth of the ciliary process, which might be a causative factor of myopia development.

The DMM Bound

DEFF Research Database (Denmark)

Emiris, Ioannis Z.; Mourrain, Bernard; Tsigaridas, Elias

2010-01-01

) resultant by means of mixed volume, as well as recent advances on aggregate root bounds for univariate polynomials, and are applicable to arbitrary positive dimensional systems. We improve upon Canny's gap theorem [7] by a factor of O(dn-1), where d bounds the degree of the polynomials, and n is the number...... bound on the number of steps that subdivision-based algorithms perform in order to isolate all real roots of a polynomial system. This leads to the first complexity bound of Milne's algorithm [22] in 2D....

Particle swarm optimization applied to automatic lens design

Science.gov (United States)

Qin, Hua

2011-06-01

This paper describes a novel application of Particle Swarm Optimization (PSO) technique to lens design. A mathematical model is constructed, and merit functions in an optical system are employed as fitness functions, which combined radiuses of curvature, thicknesses among lens surfaces and refractive indices regarding an optical system. By using this function, the aberration correction is carried out. A design example using PSO is given. Results show that PSO as optical design tools is practical and powerful, and this method is no longer dependent on the lens initial structure and can arbitrarily create search ranges of structural parameters of a lens system, which is an important step towards automatic design with artificial intelligence.

Transglutaminase involvement in UV-A damage to the eye lens

International Nuclear Information System (INIS)

Weinreb, Orly; Dovrat, A.

1996-01-01

Solar radiation is believed to be one of the major environmental factors involved in lens cataractogenesis. The purpose of the study was to investigate the mechanisms by which UV-A at 365 nm causes damage to the eye lens. Bovine lenses were placed in special culture cells for pre-incubation of 24 hr. The lenses were positioned so that the anterior surface faced the incident UV-A radiation source and were maintained in the cells during irradiation. After irradiation, lens optical quality was monitored throughout the culture period and lens epithelium, cortex and nuclear samples were taken for biochemical analysis. Transglutaminase activity in the lens was affected by the radiation. The activity of transglutaminase in lens epithelium cortex and nucleus increased as a result of the irradiation and then declined towards control levels during the culture period, as the lens recovered from the UV-A damage. Specific lens proteins αB and βB1 crystallins (the enzyme substrates) were analyzed by SDS polyacrylamid gel electrophoreses and immunoblotting with specific antibodies. Seventy-two hours after irradiation of 44.8 J cm -2 UV-A, αB crystallins were affected as was shown by the appearance of aggregation and degradation products. Some protein changes seem to be reversible. It appears that transglutaminase may be involved in the mechanism by which UV-A causes damage to the eye lens. (Author)

Integrated Lens Antennas for Multi-Pixel Receivers

Science.gov (United States)

Lee, Choonsup; Chattopadhyay, Goutam

2011-01-01

Future astrophysics and planetary experiments are expected to require large focal plane arrays with thousands of detectors. Feedhorns have excellent performance, but their mass, size, fabrication challenges, and expense become prohibitive for very large focal plane arrays. Most planar antenna designs produce broad beam patterns, and therefore require additional elements for efficient coupling to the telescope optics, such as substrate lenses or micromachined horns. An antenna array with integrated silicon microlenses that can be fabricated photolithographically effectively addresses these issues. This approach eliminates manual assembly of arrays of lenses and reduces assembly errors and tolerances. Moreover, an antenna array without metallic horns will reduce mass of any planetary instrument significantly. The design has a monolithic array of lens-coupled, leaky-wave antennas operating in the millimeter- and submillimeter-wave frequencies. Electromagnetic simulations show that the electromagnetic fields in such lens-coupled antennas are mostly confined in approximately 12 15 . This means that one needs to design a small-angle sector lens that is much easier to fabricate using standard lithographic techniques, instead of a full hyper-hemispherical lens. Moreover, this small-angle sector lens can be easily integrated with the antennas in an array for multi-pixel imager and receiver implementation. The leaky antenna is designed using double-slot irises and fed with TE10 waveguide mode. The lens implementation starts with a silicon substrate. Photoresist with appropriate thickness (optimized for the lens size) is spun on the substrate and then reflowed to get the desired lens structure. An antenna array integrated with individual lenses for higher directivity and excellent beam profile will go a long way in realizing multi-pixel arrays and imagers. This technology will enable a new generation of compact, low-mass, and highly efficient antenna arrays for use in multi

Mathematical Lens: How Much Can You Bench?

Science.gov (United States)

Bolognese, Chris A.

2013-01-01

"How Much Can You Bench?" appears in the "Mathematical Lens" section of "Mathematics Teacher." "Mathematical Lens" uses photographs as a springboard for mathematical inquiry and appears in every issue of "Mathematics Teacher." This month the mathematics behind the photograph includes finding areas…

Bacterial transmission from lens storage cases to contact lenses - Effects of lens care solutions and silver impregnation of cases

NARCIS (Netherlands)

Vermeltfoort, Pit B. J.; Hooymans, Johanna M. M.; Busscher, Henk J.; van der Mei, Henny C.

2008-01-01

The killing efficacies of multipurpose lens care solutions on planktonic and biofilm bacteria grown in polypropylene contact lens storage cases with and without silver impregnation and effects on bacterial transmission from storage cases to silicone hydrogel contact lenses were investigated. For

Piggyback intraocular lens implantation to correct pseudophakic refractive error after segmental multifocal intraocular lens implantation.

Science.gov (United States)

Venter, Jan A; Oberholster, Andre; Schallhorn, Steven C; Pelouskova, Martina

2014-04-01

To evaluate refractive and visual outcomes of secondary piggyback intraocular lens implantation in patients diagnosed as having residual ametropia following segmental multifocal lens implantation. Data of 80 pseudophakic eyes with ametropia that underwent Sulcoflex aspheric 653L intraocular lens implantation (Rayner Intraocular Lenses Ltd., East Sussex, United Kingdom) to correct residual refractive error were analyzed. All eyes previously had in-the-bag zonal refractive multifocal intraocular lens implantation (Lentis Mplus MF30, models LS-312 and LS-313; Oculentis GmbH, Berlin, Germany) and required residual refractive error correction. Outcome measurements included uncorrected distance visual acuity, corrected distance visual acuity, uncorrected near visual acuity, distance-corrected near visual acuity, manifest refraction, and complications. One-year data are presented in this study. The mean spherical equivalent ranged from -1.75 to +3.25 diopters (D) preoperatively (mean: +0.58 ± 1.15 D) and reduced to -1.25 to +0.50 D (mean: -0.14 ± 0.28 D; P < .01). Postoperatively, 93.8% of eyes were within ±0.50 D and 98.8% were within ±1.00 D of emmetropia. The mean uncorrected distance visual acuity improved significantly from 0.28 ± 0.16 to 0.01 ± 0.10 logMAR and 78.8% of eyes achieved 6/6 (Snellen 20/20) or better postoperatively. The mean uncorrected near visual acuity changed from 0.43 ± 0.28 to 0.19 ± 0.15 logMAR. There was no significant change in corrected distance visual acuity or distance-corrected near visual acuity. No serious intraoperative or postoperative complications requiring secondary intraocular lens removal occurred. Sulcoflex lenses proved to be a predictable and safe option for correcting residual refractive error in patients diagnosed as having pseudophakia. Copyright 2014, SLACK Incorporated.

Astragaloside IV prevents damage to human mesangial cells through the inhibition of the NADPH oxidase/ROS/Akt/NF‑κB pathway under high glucose conditions.

Science.gov (United States)

Sun, Li; Li, Weiping; Li, Weizu; Xiong, Li; Li, Guiping; Ma, Rong

2014-07-01

Glomerular hypertrophy and hyperfiltration are the two major pathological characteristics of the early stages of diabetic nephropathy (DN), which are respectively related to mesangial cell (MC) proliferation and a decrease in calcium influx conducted by canonical transient receptor potential cation channel 6 (TRPC6). The marked increase in the production of reactive oxygen species (ROS) induced by hyperglycemia is the main sponsor of multiple pathological pathways in DN. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is an important source of ROS production in MCs. Astragaloside IV (AS‑IV) is an active ingredient of Radix Astragali which has a potent antioxidative effect. In this study, we aimed to investigate whether high glucose (HG)‑induced NADPH oxidase activation and ROS production contribute to MC proliferation and the downregulation of TRPC6 expression; we also wished to determine the effects of AS‑IV on MCs under HG conditions. Using a human glomerular mesangial cell line, we found that treatment with AS‑IV for 48 h markedly attenuated HG‑induced proliferation and the hypertrophy of MCs in a dose‑dependent manner. The intracellular ROS level was also markedly reduced following treatment with AS‑IV. In addition, the enhanced activity of NADPH oxidase and the expression level of NADPH oxidase 4 (Nox4) protein were decreased. Treatment with AS‑IV also inhibited the phosphorylation level of Akt and IκBα in the MCs. In addition, TRPC6 protein expression and the intracellular free calcium concentration were also markedly reduced following treatment with AS‑IV under HG conditions. These results suggest that AS‑IV inhibits HG‑induced mesangial cell proliferation and glomerular contractile dysfunction through the NADPH oxidase/ROS/Akt/nuclear factor‑κB (NF‑κB) pathway, providing a new perspective for the clinical treatment of DN.

Effects of Coupling Lens on Optical Refrigeration of Semiconductors

International Nuclear Information System (INIS)

Kai, Ding; Yi-Ping, Zeng

2008-01-01

Optical refrigeration of semiconductors is encountering efficiency difficulties caused by nonradiative recombination and luminescence trapping. A commonly used approach for enhancing luminescence efficiency of a semiconductor device is coupling a lens with the device. We quantitatively study the effects of a coupling lens on optical refrigeration based on rate equations and photon recycling, and calculated cooling efficiencies of different coupling mechanisms and of different lens materials. A GaAs/GaInP heterostructure coupled with a homo-epitaxial GaInP hemispherical lens is recommended. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Single lens laser beam shaper

Science.gov (United States)

Liu, Chuyu [Newport News, VA; Zhang, Shukui [Yorktown, VA

2011-10-04

A single lens bullet-shaped laser beam shaper capable of redistributing an arbitrary beam profile into any desired output profile comprising a unitary lens comprising: a convex front input surface defining a focal point and a flat output portion at the focal point; and b) a cylindrical core portion having a flat input surface coincident with the flat output portion of the first input portion at the focal point and a convex rear output surface remote from the convex front input surface.

A benzoxazine derivative induces vascular endothelial cell apoptosis in the presence of fibroblast growth factor-2 by elevating NADPH oxidase activity and reactive oxygen species levels.

Science.gov (United States)

Zhao, Jing; He, Qiuxia; Cheng, Yizhe; Zhao, Baoxiang; Zhang, Yun; Zhang, Shangli; Miao, Junying

2009-09-01

Previously, we found that 6,8-dichloro-2,3-dihydro-3-hydroxymethyl-1,4-benzoxazine (DBO) promoted apoptosis of human umbilical vascular endothelial cells (HUVECs) deprived of growth factors. In this study, we aimed to investigate the effect of DBO and its mechanism of action on angiogenesis and apoptosis of HUVECs in the presence of fibroblast growth factor-2 (FGF-2), which promotes angiogenesis and inhibits apoptosis in vivo and in vitro. DBO significantly inhibited capillary-like tube formation by promoting apoptosis of HUVECs in the presence of FGF-2 in vitro. Furthermore, DBO elevated the levels of reactive oxygen species (ROS) and nitric oxide (NO) and increased the activity of NADPH oxidase and inducible nitric oxide synthase (iNOS) in promoting apoptosis under this condition. Moreover, when NADPH oxidase was inhibited by its specific inhibitor, dibenziodolium chloride (DPI), DBO could not elevate ROS and NO levels in HUVECs. The data suggest that DBO is a new modulator of apoptosis in vitro, and it might function by increasing the activity of NADPH oxidase and iNOS, subsequently elevating the levels of ROS and NO in HUVECs. The findings of this study provide a new small molecule for investigating the FGF-2/NADPH oxidase/iNOS signaling pathway in apoptosis.

Analytic models of plausible gravitational lens potentials

International Nuclear Information System (INIS)

Baltz, Edward A.; Marshall, Phil; Oguri, Masamune

2009-01-01

Gravitational lenses on galaxy scales are plausibly modelled as having ellipsoidal symmetry and a universal dark matter density profile, with a Sérsic profile to describe the distribution of baryonic matter. Predicting all lensing effects requires knowledge of the total lens potential: in this work we give analytic forms for that of the above hybrid model. Emphasising that complex lens potentials can be constructed from simpler components in linear combination, we provide a recipe for attaining elliptical symmetry in either projected mass or lens potential. We also provide analytic formulae for the lens potentials of Sérsic profiles for integer and half-integer index. We then present formulae describing the gravitational lensing effects due to smoothly-truncated universal density profiles in cold dark matter model. For our isolated haloes the density profile falls off as radius to the minus fifth or seventh power beyond the tidal radius, functional forms that allow all orders of lens potential derivatives to be calculated analytically, while ensuring a non-divergent total mass. We show how the observables predicted by this profile differ from that of the original infinite-mass NFW profile. Expressions for the gravitational flexion are highlighted. We show how decreasing the tidal radius allows stripped haloes to be modelled, providing a framework for a fuller investigation of dark matter substructure in galaxies and clusters. Finally we remark on the need for finite mass halo profiles when doing cosmological ray-tracing simulations, and the need for readily-calculable higher order derivatives of the lens potential when studying catastrophes in strong lenses

ANALYTICAL SOLUTIONS OF SINGULAR ISOTHERMAL QUADRUPOLE LENS

International Nuclear Information System (INIS)

Chu Zhe; Lin, W. P.; Yang Xiaofeng

2013-01-01

Using an analytical method, we study the singular isothermal quadrupole (SIQ) lens system, which is the simplest lens model that can produce four images. In this case, the radial mass distribution is in accord with the profile of the singular isothermal sphere lens, and the tangential distribution is given by adding a quadrupole on the monopole component. The basic properties of the SIQ lens have been studied in this Letter, including the deflection potential, deflection angle, magnification, critical curve, caustic, pseudo-caustic, and transition locus. Analytical solutions of the image positions and magnifications for the source on axes are derived. We find that naked cusps will appear when the relative intensity k of quadrupole to monopole is larger than 0.6. According to the magnification invariant theory of the SIQ lens, the sum of the signed magnifications of the four images should be equal to unity, as found by Dalal. However, if a source lies in the naked cusp, the summed magnification of the left three images is smaller than the invariant 1. With this simple lens system, we study the situations where a point source infinitely approaches a cusp or a fold. The sum of the magnifications of the cusp image triplet is usually not equal to 0, and it is usually positive for major cusps while negative for minor cusps. Similarly, the sum of magnifications of the fold image pair is usually not equal to 0 either. Nevertheless, the cusp and fold relations are still equal to 0 in that the sum values are divided by infinite absolute magnifications by definition.

CONTACT LENS RELATED CORNEAL ULCER

Directory of Open Access Journals (Sweden)

AGARWAL P

2010-01-01

Full Text Available A corneal ulcer caused by infection is one of the major causes of blindness worldwide. One of the recent health concerns is the increasing incidence of corneal ulcers associated with contact lens user especially if the users fail to follow specific instruction in using their contact lenses. Risk factors associated with increased risk of contact lens related corneal ulcers are:overnight wear, long duration of continuous wear, lower socio-economic classes, smoking, dry eye and poor hygiene. The presenting symptoms of contact lens related corneal ulcers include eye discomfort, foreign body sensation and lacrimation. More serious symptoms are redness (especially circum-corneal injection, severe pain, photophobia, eye discharge and blurring of vision. The diagnosis is established by a thorough slit lamp microscopic examination with fluorescein staining and corneal scraping for Gram stain and culture of the infective organism. Delay in diagnosing and treatment can cause permanent blindness, therefore an early referral to ophthalmologist and commencing of antimicrobial therapy can prevent visual loss.

Acute Ethanol Intake Induces NAD(P)H Oxidase Activation and Rhoa Translocation in Resistance Arteries.

Science.gov (United States)

Simplicio, Janaina A; Hipólito, Ulisses Vilela; Vale, Gabriel Tavares do; Callera, Glaucia Elena; Pereira, Camila André; Touyz, Rhian M; Tostes, Rita de Cássia; Tirapelli, Carlos R

2016-11-01

The mechanism underlying the vascular dysfunction induced by ethanol is not totally understood. Identification of biochemical/molecular mechanisms that could explain such effects is warranted. To investigate whether acute ethanol intake activates the vascular RhoA/Rho kinase pathway in resistance arteries and the role of NAD(P)H oxidase-derived reactive oxygen species (ROS) on such response. We also evaluated the requirement of p47phox translocation for ethanol-induced NAD(P)H oxidase activation. Male Wistar rats were orally treated with ethanol (1g/kg, p.o. gavage) or water (control). Some rats were treated with vitamin C (250 mg/kg, p.o. gavage, 5 days) before administration of water or ethanol. The mesenteric arterial bed (MAB) was collected 30 min after ethanol administration. Vitamin C prevented ethanol-induced increase in superoxide anion (O2-) generation and lipoperoxidation in the MAB. Catalase and superoxide dismutase activities and the reduced glutathione, nitrate and hydrogen peroxide (H2O2) levels were not affected by ethanol. Vitamin C and 4-methylpyrazole prevented the increase on O2- generation induced by ethanol in cultured MAB vascular smooth muscle cells. Ethanol had no effect on phosphorylation levels of protein kinase B (Akt) and eNOS (Ser1177 or Thr495 residues) or MAB vascular reactivity. Vitamin C prevented ethanol-induced increase in the membrane: cytosol fraction ratio of p47phox and RhoA expression in the rat MAB. Acute ethanol intake induces activation of the RhoA/Rho kinase pathway by a mechanism that involves ROS generation. In resistance arteries, ethanol activates NAD(P)H oxidase by inducing p47phox translocation by a redox-sensitive mechanism. O mecanismo da disfunção vascular induzido pelo consumo de etanol não é totalmente compreendido. Justifica-se, assim a identificação de mecanismos bioquímicos e moleculares que poderiam explicar tais efeitos. Investigar se a ingestão aguda de etanol ativa a via vascular RhoA/Rho quinase

NecroX-7 prevents oxidative stress-induced cardiomyopathy by inhibition of NADPH oxidase activity in rats

Energy Technology Data Exchange (ETDEWEB)

Park, Joonghoon; Park, Eok; Ahn, Bong-Hyun; Kim, Hyoung Jin [LG Life Sciences Ltd., R and D Park, Daejeon, 305-380 (Korea, Republic of); Park, Ji-hoon [Department of Biochemistry, School of Medicine, Chungnam National University, Daejeon, 301-747 (Korea, Republic of); Koo, Sun Young; Kwak, Hyo-Shin; Park, Heui Sul; Kim, Dong Wook; Song, Myoungsub; Yim, Hyeon Joo; Seo, Dong Ook [LG Life Sciences Ltd., R and D Park, Daejeon, 305-380 (Korea, Republic of); Kim, Soon Ha, E-mail: shakim@lgls.com [LG Life Sciences Ltd., R and D Park, Daejeon, 305-380 (Korea, Republic of)

2012-08-15

Oxidative stress is one of the causes of cardiomyopathy. In the present study, NecroXs, novel class of mitochondrial ROS/RNS scavengers, were evaluated for cardioprotection in in vitro and in vivo model, and the putative mechanism of the cardioprotection of NecroX-7 was investigated by global gene expression profiling and subsequent biochemical analysis. NecroX-7 prevented tert-butyl hydroperoxide (tBHP)-induced death of H9C2 rat cardiomyocytes at EC{sub 50} = 0.057 μM. In doxorubicin (DOX)-induced cardiomyopathy in rats, NecroX-7 significantly reduced the plasma levels of creatine kinase (CK-MB) and lactate dehydrogenase (LDH) which were increased by DOX treatment (p < 0.05). Microarray analysis revealed that 21 genes differentially expressed in tBHP-treated H9C2 cells were involved in ‘Production of reactive oxygen species’ (p = 0.022), and they were resolved by concurrent NecroX-7 treatment. Gene-to-gene networking also identified that NecroX-7 relieved cell death through Ncf1/p47phox and Rac2 modulation. In subsequent biochemical analysis, NecroX-7 inhibited NADPH oxidase (NOX) activity by 53.3% (p < 0.001). These findings demonstrate that NecroX-7, in part, provides substantial protection of cardiomyopathy induced by tBHP or DOX via NOX-mediated cell death. -- Highlights: ► NecroX-7 prevented tert-butyl hydroperoxide-induced in vitro cardiac cell death. ► NecroX-7 ameliorated doxorubicin-induced in vivo cardiomyopathy. ► NecroX-7 prevented oxidative stress and necrosis-enriched transcriptional changes. ► NecroX-7 effectively inhibited NADPH oxidase activation. ► Cardioprotection of Necro-7 was brought on by modulation of NADPH oxidase activity.

Combined 23-gauge transconjunctival vitrectomy and scleral fixation of intraocular lens without conjunctival dissection in managing lens complications.

Science.gov (United States)

Yeung, Ling; Wang, Nan-Kai; Wu, Wei-Chi; Chen, Kuan-Jen

2018-04-23

To evaluate the safety and efficacy of combined 23-gauge transconjunctival pars plana vitrectomy and scleral fixation of intraocular lens (IOL) without conjunctival dissection. A retrospective study in Chang Gung Memorial Hospital, Keelung and Taoyuan, Taiwan. Patients receiving combined 23-gauge transconjunctival pars plana vitrectomy and scleral fixation of IOL without conjunctival dissection were enrolled. The ocular findings, causes of lens complication, surgical procedures, type of IOL used, and complications were documented. We included 40 eyes from 39 patients (27 male, 12 female) with a mean age of 59.5 [standard deviation (±) 14.8] years old. The mean follow-up duration was 6.8 ± 5.4 months. The cause of lens complications was ocular trauma in 24 (60%) eyes, cataract surgery complications in 11 (28%) eyes, and spontaneous subluxation of crystalline lens in 5 (13%) eyes. The overall best corrected visual acuity (BCVA) (logMAR) improved from 1.359 ± 0.735 to 0.514 ± 0.582 (p IOL decentration was found in 3 (8%) eyes and 1 (3%) eye respectively. Combined 23-gauge transconjunctival vitrectomy and scleral fixation of IOL without conjunctival dissection is effective and safe in managing a wide variety of lens complications, with good postoperative comfort and visual recovery. Retrospective study, not applicable.

Tunable Focus Liquid Lens with Radial-Patterned Electrode

Directory of Open Access Journals (Sweden)

Miao Xu

2015-08-01

Full Text Available A dielectric liquid lens is prepared based on our previous work. By optimizing the device structure, the liquid lens presents a converging focus with good resolution and changes its focal length over a broad range with a low driving voltage. For a liquid lens with ~2.3 mm diameter in the relaxed state, it can resolve ~40 lp/mm. The resolution does not degrade during focus change. Its focal length can be varied from ~12 to ~5 mm when the applied voltage is changed from 0 to 28 Vrms. The response time of one cycle is ~2.5 s. Our liquid lens, with a low driving voltage for a large dynamic range, has potential applications in imaging, biometrics, optoelectronic, and lab-on-chip devices.

Development of a Laue lens for nuclear astrophysics

International Nuclear Information System (INIS)

Barriere, N.

2008-04-01

The Laue lenses we study focuses in the domain of 0.1-1 MeV thanks to Bragg diffraction in the volume of a large number of small crystal tiles. The focal length of a typical Laue lens system is of the order of 100 m. This requirement calls for two formation flying satellites maintaining lens and detector at the focal distance. The major breakthrough of Laue lenses is to decouple collecting area from detector area. Concentrating a signal from the large area of a Laue lens onto a small focal spot dramatically increases the signal over background ratio with respect to present technologies. Here is the reason for the long awaited leap in sensitivity. The objective of the present thesis was to improve the concept, finding viable technical solutions towards a future space mission. Two aspects of the lens development have been highlighted in this thesis: the first one is an analytical model of the lens that is used to calculate and improve the performance of a certain configuration, the second aspect concerns the search and the characterization of diffracting media of interest. The lens model developed relies on a fast semi-analytical simulation library, permitting to build several design- and optimisation-tools. For the configuration of a given lens, this code computes the resulting effective area and point spread function in a handful of seconds. The model helps finding lens configurations (mass, pack ratio of the lens rings,...) which are automatically refined to match with effective area and energy coverage constraints. These tools have been used to investigate various design aspects, such as the influence of focal length, size, mosaic spread, structure and materials of crystals, etc... The central evaluation criterion in the model is a figure of merit, based on the compactness of the focal spot and the intensity of the collected signal. The second part of this work addresses the actual search and characterization of crystals potentially interesting for Laue lenses

Crystallization and preliminary X-ray analysis of the NADPH-dependent 3-quinuclidinone reductase from Rhodotorula rubra

International Nuclear Information System (INIS)

Takeshita, Daijiro; Kataoka, Michihiko; Miyakawa, Takuya; Miyazono, Ken-ichi; Uzura, Atsuko; Nagata, Koji; Shimizu, Sakayu; Tanokura, Masaru

2009-01-01

The NADPH-dependent 3-quinuclidinone reductase from Rhodotorula rubra was expressed, purified, and crystallized and X-ray diffraction data of this crystal were collected to 2.2 Å resolution. (R)-3-Quinuclidinol is a useful compound that is applicable to the synthesis of various pharmaceuticals. The NADPH-dependent carbonyl reductase 3-quinuclidinone reductase from Rhodotorula rubra catalyzes the stereospecific reduction of 3-quinuclidinone to (R)-3-quinuclidinol and is expected to be utilized in industrial production of this alcohol. 3-Quinuclidinone reductase from R. rubra was expressed in Escherichia coli and purified using Ni-affinity and ion-exchange column chromatography. Crystals of the protein were obtained by the sitting-drop vapour-diffusion method using PEG 8000 as the precipitant. The crystals belonged to space group P4 1 2 1 2, with unit-cell parameters a = b = 91.3, c = 265.4 Å, and diffracted X-rays to 2.2 Å resolution. The asymmetric unit contained four molecules of the protein and the solvent content was 48.4%

Thioredoxin and NADPH-Dependent Thioredoxin Reductase C Regulation of Tetrapyrrole Biosynthesis.

Science.gov (United States)

Da, Qingen; Wang, Peng; Wang, Menglong; Sun, Ting; Jin, Honglei; Liu, Bing; Wang, Jinfa; Grimm, Bernhard; Wang, Hong-Bin

2017-10-01

In chloroplasts, thioredoxin (TRX) isoforms and NADPH-dependent thioredoxin reductase C (NTRC) act as redox regulatory factors involved in multiple plastid biogenesis and metabolic processes. To date, less is known about the functional coordination between TRXs and NTRC in chlorophyll biosynthesis. In this study, we aimed to explore the potential functions of TRX m and NTRC in the regulation of the tetrapyrrole biosynthesis (TBS) pathway. Silencing of three genes, TRX m1 , TRX m2 , and TRX m4 ( TRX ms ), led to pale-green leaves, a significantly reduced 5-aminolevulinic acid (ALA)-synthesizing capacity, and reduced accumulation of chlorophyll and its metabolic intermediates in Arabidopsis ( Arabidopsis thaliana ). The contents of ALA dehydratase, protoporphyrinogen IX oxidase, the I subunit of Mg-chelatase, Mg-protoporphyrin IX methyltransferase (CHLM), and NADPH-protochlorophyllide oxidoreductase were decreased in triple TRX m- silenced seedlings compared with the wild type, although the transcript levels of the corresponding genes were not altered significantly. Protein-protein interaction analyses revealed a physical interaction between the TRX m isoforms and CHLM. 4-Acetoamido-4-maleimidylstilbene-2,2-disulfonate labeling showed the regulatory impact of TRX ms on the CHLM redox status. Since CHLM also is regulated by NTRC (Richter et al., 2013), we assessed the concurrent functions of TRX m and NTRC in the control of CHLM. Combined deficiencies of three TRX m isoforms and NTRC led to a cumulative decrease in leaf pigmentation, TBS intermediate contents, ALA synthesis rate, and CHLM activity. We discuss the coordinated roles of TRX m and NTRC in the redox control of CHLM stability with its corollary activity in the TBS pathway. © 2017 American Society of Plant Biologists. All Rights Reserved.

TU-E-201-02: Eye Lens Dosimetry From CT Perfusion Studies

Energy Technology Data Exchange (ETDEWEB)

Zhang, D. [Toshiba America Medical Systems (United States)

2015-06-15

Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

TU-E-201-00: Eye Lens Dosimetry for Patients and Staff

Energy Technology Data Exchange (ETDEWEB)

NONE

2015-06-15

Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

TU-E-201-02: Eye Lens Dosimetry From CT Perfusion Studies

International Nuclear Information System (INIS)

Zhang, D.

2015-01-01

Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

TU-E-201-00: Eye Lens Dosimetry for Patients and Staff

International Nuclear Information System (INIS)

2015-01-01

Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

Congruence between PM H+-ATPase and NADPH oxidase during root growth: a necessary probability.

Science.gov (United States)

Majumdar, Arkajo; Kar, Rup Kumar

2018-07-01

Plasma membrane (PM) H + -ATPase and NADPH oxidase (NOX) are two key enzymes responsible for cell wall relaxation during elongation growth through apoplastic acidification and production of ˙OH radical via O 2 ˙ - , respectively. Our experiments revealed a putative feed-forward loop between these enzymes in growing roots of Vigna radiata (L.) Wilczek seedlings. Thus, NOX activity was found to be dependent on proton gradient generated across PM by H + -ATPase as evident from pharmacological experiments using carbonyl cyanide m-chlorophenylhydrazone (CCCP; protonophore) and sodium ortho-vanadate (PM H + -ATPase inhibitor). Conversely, H + -ATPase activity retarded in response to different ROS scavengers [CuCl 2 , N, N' -dimethylthiourea (DMTU) and catalase] and NOX inhibitors [ZnCl 2 and diphenyleneiodonium (DPI)], while H 2 O 2 promoted PM H + -ATPase activity at lower concentrations. Repressing effects of Ca +2 antagonists (La +3 and EGTA) on the activity of both the enzymes indicate its possible mediation. Since, unlike animal NOX, the plant versions do not possess proton channel activity, harmonized functioning of PM H + -ATPase and NOX appears to be justified. Plasma membrane NADPH oxidase and H + -ATPase are functionally synchronized and they work cooperatively to maintain the membrane electrical balance while mediating plant cell growth through wall relaxation.

Organically bound tritium

International Nuclear Information System (INIS)

Diabate, S.; Strack, S.

1993-01-01

Tritium released into the environment may be incorporated into organic matter. Organically bound tritium in that case will show retention times in organisms that are considerably longer than those of tritiated water which has significant consequences on dose estimates. This article reviews the most important processes of organically bound tritium production and transport through food networks. Metabolic reactions in plant and animal organisms with tritiated water as a reaction partner are of great importance in this respect. The most important production process, in quantitative terms, is photosynthesis in green plants. The translocation of organically bound tritium from the leaves to edible parts of crop plants should be considered in models of organically bound tritium behavior. Organically bound tritium enters the human body on several pathways, either from the primary producers (vegetable food) or at a higher tropic level (animal food). Animal experiments have shown that the dose due to ingestion of organically bound tritium can be up to twice as high as a comparable intake of tritiated water in gaseous or liquid form. In the environment, organically bound tritium in plants and animals is often found to have higher specific tritium concentrations than tissue water. This is not due to some tritium enrichment effects but to the fact that no equilibrium conditions are reached under natural conditions. 66 refs

Evolutionary origin and function of NOX4-art, an arthropod specific NADPH oxidase

OpenAIRE

Gandara, Ana Caroline Paiva; Torres, Andr?; Bahia, Ana Cristina; Oliveira, Pedro L.; Schama, Renata

2017-01-01

Background NADPH oxidases (NOX) are ROS producing enzymes that perform essential roles in cell physiology, including cell signaling and antimicrobial defense. This gene family is present in most eukaryotes, suggesting a common ancestor. To date, only a limited number of phylogenetic studies of metazoan NOXes have been performed, with few arthropod genes. In arthropods, only NOX5 and DUOX genes have been found and a gene called NOXm was found in mosquitoes but its origin and function has not b...

Calpain expression and activity during lens fiber cell differentiation.

Science.gov (United States)

De Maria, Alicia; Shi, Yanrong; Kumar, Nalin M; Bassnett, Steven

2009-05-15

In animal models, the dysregulated activity of calcium-activated proteases, calpains, contributes directly to cataract formation. However, the physiological role of calpains in the healthy lens is not well defined. In this study, we examined the expression pattern of calpains in the mouse lens. Real time PCR and Western blotting data indicated that calpain 1, 2, 3, and 7 were expressed in lens fiber cells. Using controlled lysis, depth-dependent expression profiles for each calpain were obtained. These indicated that, unlike calpain 1, 2, and 7, which were most abundant in cells near the lens surface, calpain 3 expression was strongest in the deep cortical region of the lens. We detected calpain activities in vitro and showed that calpains were active in vivo by microinjecting fluorogenic calpain substrates into cortical fiber cells. To identify endogenous calpain substrates, membrane/cytoskeleton preparations were treated with recombinant calpain, and cleaved products were identified by two-dimensional difference electrophoresis/mass spectrometry. Among the calpain substrates identified by this approach was alphaII-spectrin. An antibody that specifically recognized calpain-cleaved spectrin was used to demonstrate that spectrin is cleaved in vivo, late in fiber cell differentiation, at or about the time that lens organelles are degraded. The generation of the calpain-specific spectrin cleavage product was not observed in lens tissue from calpain 3-null mice, indicating that calpain 3 is uniquely activated during lens fiber differentiation. Our data suggest a role for calpains in the remodeling of the membrane cytoskeleton that occurs with fiber cell maturation.

Contact lens wear and dry eyes: challenges and solutions

Directory of Open Access Journals (Sweden)

Markoulli M

2017-02-01

Full Text Available Maria Markoulli, Sailesh Kolanu School of Optometry and Vision Science, University of New South Wales, Sydney, NSW, Australia Abstract: The number of contact lens wearers worldwide has remained relatively stable over the past decade, despite the investment that has gone into contact lens technology. This is largely because 10%–50% of wearers dropout of contact lens wear within 3 years of commencement; the most common reason cited being contact lens discomfort (CLD. Of the symptoms reported, sensation of dry eye is the most common. Given the outcome of reduced wearing time, increased chair time, and ultimate contact lens discontinuation, the challenge is to identify the warning signs of CLD early on. Clinically detectable changes such as conjunctival staining, conjunctival indentation, conjunctival epithelial flap formation, lid wiper epitheliopathy, Demodex blepharitis, and meibomian gland dysfunction have been linked to CLD, highlighting the need to perform regular aftercare visits to identify these changes. At a cellular level, conjunctival metaplasia and reduced goblet cell density have been linked to CLD, leading to a downstream effect on the tear film breakup time of contact lens wearers. These factors suggest a strong link between CLD and friction, raising the need to target this as a means of minimizing CLD. The purpose of this review is to identify the clinical signs that relate to CLD as a means of earlier detection and management in order to combat contact lens dropout. Keywords: contact lens discomfort, dry eye disease, lid wiper epitheliopathy, tear film biomarkers, meibomian gland dysfunction

Manipulation of malic enzyme in Saccharomyces cerevisiae for increasing NADPH production capacity aerobically in different cellular compartments

DEFF Research Database (Denmark)

Santos, Maria Margarida M. dos; Vijayendran, Raghevendran; Kotter, P.

2004-01-01

The yeast Saccharomyces cerevisiae is an attractive cell factory, but in many cases there are constraints related with balancing the formation and consumption of redox cofactors. In this work, we studied the effect of having an additional source of NADPH in the cell. In order to do this, two...

Physical Uncertainty Bounds (PUB)

Energy Technology Data Exchange (ETDEWEB)

Vaughan, Diane Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Dean L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2015-03-19

This paper introduces and motivates the need for a new methodology for determining upper bounds on the uncertainties in simulations of engineered systems due to limited fidelity in the composite continuum-level physics models needed to simulate the systems. We show that traditional uncertainty quantification methods provide, at best, a lower bound on this uncertainty. We propose to obtain bounds on the simulation uncertainties by first determining bounds on the physical quantities or processes relevant to system performance. By bounding these physics processes, as opposed to carrying out statistical analyses of the parameter sets of specific physics models or simply switching out the available physics models, one can obtain upper bounds on the uncertainties in simulated quantities of interest.

Customer loyalty among daily disposable contact lens wearers.

Science.gov (United States)

Patel, Neelam I; Naroo, Shehzad A; Eperjesi, Frank; Rumney, Nicholas J

2015-02-01

Optometric practices offer contact lenses as cash sale items or as part of monthly payment plans. With the contact lens market becoming increasingly competitive, patients are opting to purchase lenses from supermarkets and Internet suppliers. Monthly payment plans are often implemented to improve loyalty. This study aimed to compare behavioural loyalty between monthly payment plan members and non-members. BBR Optometry Ltd offers a monthly payment plan (Eyelife™) to their contact lens wearers. A retrospective audit of 38 Eyelife™ members (mean±SD: 42.7±15.0 years) and 30 non-members (mean±SD: 40.8±16.7 years) was conducted. Revenue and profits generated, service uptake and product sales between the two groups were compared over a fixed period of 18 months. Eyelife™ members generated significantly higher professional fee revenue (Ployalty among contact lens wearers, particularly service uptake and volume of lens purchases. Additionally the greater professional fees generated, render monthly payment plans an attractive business model and practice builder. Copyright © 2014 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Silencing of NADPH-Dependent Oxidoreductase Genes (yqhD and dkgA) in Furfural-Resistant Ethanologenic Escherichia coli▿

Science.gov (United States)

Miller, E. N.; Jarboe, L. R.; Yomano, L. P.; York, S. W.; Shanmugam, K. T.; Ingram, L. O.

2009-01-01

Low concentrations of furfural are formed as a side product during the dilute acid hydrolysis of hemicellulose. Growth is inhibited by exposure to furfural but resumes after the complete reduction of furfural to the less toxic furfuryl alcohol. Growth-based selection was used to isolate a furfural-resistant mutant of ethanologenic Escherichia coli LY180, designated strain EMFR9. Based on mRNA expression levels in the parent and mutant in response to furfural challenge, genes encoding 12 oxidoreductases were found to vary by more than twofold (eight were higher in EMFR9; four were higher in the parent). All 12 genes were cloned. When expressed from plasmids, none of the eight genes in the first group increased furfural tolerance in the parent (LY180). Expression of three of the silenced genes (yqhD, dkgA, and yqfA) in EMFR9 was found to decrease furfural tolerance compared to that in the parent. Purified enzymes encoded by yqhD and dkgA were shown to have NADPH-dependent furfural reductase activity. Both exhibited low Km values for NADPH (8 μM and 23 μM, respectively), similar to those of biosynthetic reactions. Furfural reductase activity was not associated with yqfA. Deleting yqhD and dkgA in the parent (LY180) increased furfural tolerance, but not to the same extent observed in the mutant EMFR9. Together, these results suggest that the process of reducing furfural by using an enzyme with a low Km for NADPH rather than a direct inhibitory action is the primary cause for growth inhibition by low concentrations of furfural. PMID:19429550

Design of LED projector based on gradient-index lens

Science.gov (United States)

Qian, Liyong; Zhu, Xiangbing; Cui, Haitian; Wang, Yuanhang

2018-01-01

In this study, a new type of projector light path is designed to eliminate the deficits of existing projection systems, such as complex structure and low collection efficiency. Using a three-color LED array as the lighting source, by means of the special optical properties of a gradient-index lens, the complex structure of the traditional projector is simplified. Traditional components, such as the color wheel, relay lens, and mirror, become unnecessary. In this way, traditional problems, such as low utilization of light energy and loss of light energy, are solved. With the help of Zemax software, the projection lens is optimized. The optimized projection lens, LED, gradient-index lens, and digital micromirror device are imported into Tracepro. The ray tracing results show that both the utilization of light energy and the uniformity are improved significantly.

[Lens luxation in dogs: a retrospective study of 134 dogs (2000-2011)].

Science.gov (United States)

Betschart; Hässig; Spiess

2014-03-01

This retrospective study evaluated cases of lens luxation in dogs that were documented at the University of Zurich Veterinary Teaching Hospital between 2000 and 2011. A total 134 dogs were included in the study. This population of dogs with lens luxation represents 0.41 % of all dogs presented to the Zurich Veterinary Teaching Hospital (32'523) and 3.02 % of all dogs presented to the ophthalmology service during the same time period. The 134 dogs represented over 40 different breeds, including mixed breeds. 63 of the dogs were male, 71 were female. The 134 dogs were divided in primary lens luxation (86 of the 134 dogs, 64 %) and secondary lens luxation (48 dogs, 36 %). The most frequent causes for secondary lens luxation were glaucoma (58 %), cataract (19 %) and trauma (17 %). This study shows the predisposition for primary lens luxations in terrier breeds, Chinese Crested dogs, Pinscher and Spitz. In contrast, Siberian Huskies, Basset Hounds, Bearded Collies, Cairn Terriers, mixed breed dogs, Bolonka Zwetna, Boston Terriers, Borzoi, Doberman, Eurasian, Leonberg, Luzerner Niederlaufhund and Weimaraner suffered significantly more often from secondary lens luxation. There was no sex predilection for primary or secondary lens luxation. Dogs with primary lens luxation were on average 7.39 ± 3.02 years old, which is significantly younger than the dogs with secondary lens luxation (9.12 ± 3.38 years). Dogs with primary lens luxation showed a significantly higher rate of a bilateral development than those with secondary lens luxation (85.5 % of the dogs with primary lens luxation and only 14.5 % of the dogs with secondary lens luxation showed it in both their eyes).

Applanation tonometry in silicone hydrogel contact lens wearers.

Science.gov (United States)

Allen, R J; Dev Borman, A; Saleh, G M

2007-12-01

Previous studies have investigated intraocular pressure (IOP) measurements through conventional soft (hydrogel) therapeutic contact lenses, and have found that an accurate IOP can be recorded in normal eyes, and in eyes with abnormal anterior segments. The IOP measurement through soft contact lenses may be affected by the water content and centre thickness of the lens. Silicone hydrogel contact lenses are now being used as therapeutic contact lenses due to their high oxygen permeability. The purpose of this study is to investigate if IOP can be accurately measured in a subject wearing a silicone hydrogel contact lens. In a cohort study, the IOP was measured with a Goldmann applanation tonometer without a contact lens and then repeated with a hydrogel contact lens in situ. The IOP of 20 eyes of 10 volunteers with no ocular pathology was measured. The mean difference (+/-S.D.) found between IOP measurement with (mean 15.55+/-1.70 mmHg) and without (mean 16.05+/-1.90 mmHg) contact lens was found to be -0.5+/-0.89 mmHg. Statistical analysis was performed which revealed a correlation coefficient of 0.89. No significant statistical difference was found between the two groups with paired t-test (p=0.19). Accurate measurement of IOP by applanation tonometry can be achieved through a silicone hydrogel contact lens.

Dark secrets behind the shimmer of contact lens: the Indian scenario

Directory of Open Access Journals (Sweden)

Singh Deepak

2009-05-01

Full Text Available Abstract Background We studied the bacteriological profile of soft contact lens and its accessories among the asymptomatic subjects and monitored the compliance level with the lens use and its cleaning protocol. Findings A total of 115 (104 daily wear and 11 extended wear subjects using contact lens were studied. Data regarding the duration of use and frequency and method of cleaning were recorded. Contact lens, lens cases, preserving solutions and tips of solution bottles were the samples collected. The isolates were identified on the basis of their phenotypic characters. Samples from 24 subjects (21 daily wear and 3 extended wear were found contaminated. Of the 24 contaminated cases, 23 showed medium adherence to the cleaning protocol. Contamination rate was higher among the 56 daily wear lens users who used same lens for 2 years and more, than the 48 users who used their lenses for less than 2 years. Lens case contamination was found in all the 24 cases. The bacteria isolated were Citrobacter freundii, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus epidermidis and Streptococcus pneumoniae. In extended wear lens users, there was no change in microbial flora on repeating the cultures on day 7 and 14. Conclusion Non-compliance with contact lens use may lead to invitation of microbial flora. The accumulation of these bacteria may act as a precursor to biofilm formation, thus colonizing the lens accessories as well. The bacteria isolated in this study were similar to the ones causing microbial keratitis thus, predisposing the otherwise asymptomatic subjects to permanent visual damage.

Evolution of NADPH-cytochrome P450 oxidoreductases (POR) in Apiales - POR 1 is missing

DEFF Research Database (Denmark)

Andersen, Trine Bundgaard; Hansen, Niels Bjørn; Laursen, Tomas

2016-01-01

The NADPH-dependent cytochrome P450 oxidoreductase (POR) is the obligate electron donor to eukaryotic microsomal cytochromes P450 enzymes. The number of PORs within plant species is limited to one to four isoforms, with the most common being two PORs per plant. These enzymes provide electrons to ...... (available from the SRA at NCBI). All three genes were shown to be functional upon reconstitution into nanodiscs, confirming that none of the isoforms are pseudogenes....

CMU DeepLens: deep learning for automatic image-based galaxy-galaxy strong lens finding

Science.gov (United States)

Lanusse, François; Ma, Quanbin; Li, Nan; Collett, Thomas E.; Li, Chun-Liang; Ravanbakhsh, Siamak; Mandelbaum, Rachel; Póczos, Barnabás

2018-01-01

Galaxy-scale strong gravitational lensing can not only provide a valuable probe of the dark matter distribution of massive galaxies, but also provide valuable cosmological constraints, either by studying the population of strong lenses or by measuring time delays in lensed quasars. Due to the rarity of galaxy-scale strongly lensed systems, fast and reliable automated lens finding methods will be essential in the era of large surveys such as Large Synoptic Survey Telescope, Euclid and Wide-Field Infrared Survey Telescope. To tackle this challenge, we introduce CMU DeepLens, a new fully automated galaxy-galaxy lens finding method based on deep learning. This supervised machine learning approach does not require any tuning after the training step which only requires realistic image simulations of strongly lensed systems. We train and validate our model on a set of 20 000 LSST-like mock observations including a range of lensed systems of various sizes and signal-to-noise ratios (S/N). We find on our simulated data set that for a rejection rate of non-lenses of 99 per cent, a completeness of 90 per cent can be achieved for lenses with Einstein radii larger than 1.4 arcsec and S/N larger than 20 on individual g-band LSST exposures. Finally, we emphasize the importance of realistically complex simulations for training such machine learning methods by demonstrating that the performance of models of significantly different complexities cannot be distinguished on simpler simulations. We make our code publicly available at https://github.com/McWilliamsCenter/CMUDeepLens.

Phacoemulsification using iris hooks and scleral fixation of the intraocular lens in patients with secondary glaucoma associated with lens subluxation.

Science.gov (United States)

Ma, K T; Lee, H K; Seong, G J; Kim, C Y

2008-09-01

We described the techniques and results of phacoemulsification using iris hook and scleral fixation of intraocular lens (IOL) in patients with secondary glaucoma associated with lens subluxation. Eight eyes of seven patients with secondary glaucoma associated with lens dislocation, who had undergone the surgery, were retrospectively reviewed. At a mean of 23.5 months+/-13.6 (SD) after the surgery, the mean best-corrected visual acuity improved from 0.24+/-0.21 to 0.83+/-0.3, and mean intraocular pressure (IOP) was changed from 38.4+/-11.4 to 15.5+/-1.8 mmHg at the final examination. There were no vitreoretinal complications except cystoid macular oedema in one eye. The technique appears to be safe and effective in terms of visual rehabilitation and controlling IOP in patients with secondary glaucoma associated with lens subluxation.

ECTOPIC LENS EXTRACTION IN CHILDREN

Directory of Open Access Journals (Sweden)

Vladimir Pfeifer

2002-12-01

Full Text Available Background. Ectopia lentis continues to be a therapeutic challenge for ophthalmologists. It can occur as an isolated condition, after ocular trauma, in association with other ocular disorders, as part of a systemic mesodermal disease or a complication of general metabolic disorders. Minimal subluxation of the lens may cause no visual symptoms, but in more advanced cases serious optical disturbances arise. The most important is amblyopia. Surgical treatment options include iris manipulation, lens discission, aspiration, intracapsular or extracapsular extraction, and pars plana lensectomy. The choice of surgical technique remains controversial, in part because of the historically poor visual results and high rate of perioperative complications, including vitreous loss and retinal detachment.Methods. We describe a surgical technique based on the use of the Cionni endocapsular tension ring, dry irrigation aspiration of lens material, centration of the capsular bag and foldable intraocular lens implantation into the bag. With mentioned surgical technique 8 patients were operated; 4 boys and 4 girls, together 11 eyes.Results. The final BCVA after follow up period improved in 9 eyes and it remained the same as before operation in one eye. Statistical comparison of preoperative and postoperative visual acuities showed significant improvement. On the other hand there was no correlation between preoperative and postoperative visual acuity.Conclusions. This surgical procedure is an alternative approach in solving this challenging cases of ectopia lentis with good postoperative visual rehabilitation.

Chlorella induces stomatal closure via NADPH oxidase-dependent ROS production and its effects on instantaneous water use efficiency in Vicia faba.

Directory of Open Access Journals (Sweden)

Yan Li

Full Text Available Reactive oxygen species (ROS have been established to participate in stomatal closure induced by live microbes and microbe-associated molecular patterns (MAMPs. Chlorella as a beneficial microorganism can be expected to trigger stomatal closure via ROS production. Here, we reported that Chlorella induced stomatal closure in a dose-and time-dependent manner in epidermal peels of Vicia faba. Using pharmacological methods in this work, we found that the Chlorella-induced stomatal closure was almost completely abolished by a hydrogen peroxide (H2O2 scavenger, catalase (CAT, significantly suppressed by an NADPH oxidase inhibitor, diphenylene iodonium chloride (DPI, and slightly affected by a peroxidase inhibitor, salicylhydroxamic acid (SHAM, suggesting that ROS production involved in Chlorella-induced stomatal closure is mainly mediated by DPI-sensitive NADPH oxidase. Additionally, Exogenous application of optimal concentrations of Chlorella suspension improved instantaneous water use efficiency (WUEi in Vicia faba via a reduction in leaf transpiration rate (E without a parallel reduction in net photosynthetic rate (Pn assessed by gas-exchange measurements. The chlorophyll fluorescence and content analysis further demonstrated that short-term use of Chlorella did not influence plant photosynthetic reactions center. These results preliminarily reveal that Chlorella can trigger stomatal closure via NADPH oxidase-dependent ROS production in epidermal strips and improve WUEi in leave levels.

Review on prevention of bacterial adhesion on contact lens using plasma treatment

Science.gov (United States)

Ramli, N. A. H.; Zaaba, S. K.; Mustaffa, M. T.; Zakaria, A.; Shahriman A., B.

2017-03-01

Many researches had been conducted to enhance the properties of contact lens. Most of the research conducted discussed on the factors that affect the adhesion process to contact lenses, rate of contact lens contamination, and type of microbe that adhere on the contact lens surface and contact lens casing. Studies on the proposed strategies or technology that can be used to slower down the formation of bacteria on contact lens are being explored. New technologies or strategies to prevent or slow down the adhesion of bacteria on contact lens have become a priority in this area. This review paper covers two main aspects, namely factor that affect the bacteria adhesion on contact lens and also the introduction of plasma treatment as a potential method for contact lens treatment.

Effect of infrared radiation on the lens

Directory of Open Access Journals (Sweden)

Aly Eman

2011-01-01

Full Text Available Background: Infrared (IR radiation is becoming more popular in industrial manufacturing processes and in many instruments used for diagnostic and therapeutic application to the human eye. Aim : The present study was designed to investigate the effect of IR radiation on rabbit′s crystalline lens and lens membrane. Materials and Methods: Fifteen New Zealand rabbits were used in the present work. The rabbits were classified into three groups; one of them served as control. The other two groups were exposed to IR radiation for 5 or 10 minutes. Animals from these two irradiated groups were subdivided into two subgroups; one of them was decapitated directly after IR exposure, while the other subgroup was decapitated 1 hour post exposure. IR was delivered from a General Electric Lamp model 250R 50/10, placed 20 cm from the rabbit and aimed at each eye. The activity of Na + -K + ATPase was measured in the lens membrane. Soluble lens proteins were extracted and the following measurements were carried out: estimation of total soluble protein, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE and Fourier transform infrared (FTIR spectroscopy. For comparison between multiple groups, analysis of variance was used with significance level set at P < 0.001. Results: The results indicated a change in the molecular weight of different lens crystalline accompanied with changes in protein backbone structure. These changes increased for the groups exposed to IR for 10 minutes. Moreover, the activity of Na + -K + ATPase significantly decreased for all groups. Conclusions: The protein of eye lens is very sensitive to IR radiation which is hazardous and may lead to cataract.

Tomographic method for measurement of the gradient refractive index of the crystalline lens. I. The spherical fish lens.

Science.gov (United States)

Acosta, Eva; Vazquez, Daniel; Garner, Leon; Smith, George

2005-03-01

We present an iterative tomographic algorithm to reconstruct refractive-index profiles for meridional planes of the lens of the spherical fish eye from measurements of deflection angles of refracted rays. Numerical simulations show that the algorithm allows accuracy up to the fourth decimal place, provided that the refractive index can be regarded as an analytical function of the radial coordinate and the experimental errors are neglected. An experimental demonstration is given by applying the algorithm to retrieve the refractive-index profile of a spherical fish lens. The method is conceptually simple and does not require matching of the index of the surrounding medium to that of the surface of the lens, and the related iterative algorithm rapidly converges.

NADPH Oxidase Activity in Cerebral Arterioles Is a Key Mediator of Cerebral Small Vessel Disease-Implications for Prevention.

Science.gov (United States)

McCarty, Mark F

2015-04-15

Cerebral small vessel disease (SVD), a common feature of brain aging, is characterized by lacunar infarcts, microbleeds, leukoaraiosis, and a leaky blood-brain barrier. Functionally, it is associated with cognitive decline, dementia, depression, gait abnormalities, and increased risk for stroke. Cerebral arterioles in this syndrome tend to hypertrophy and lose their capacity for adaptive vasodilation. Rodent studies strongly suggest that activation of Nox2-dependent NADPH oxidase activity is a crucial driver of these structural and functional derangements of cerebral arterioles, in part owing to impairment of endothelial nitric oxide synthase (eNOS) activity. This oxidative stress may also contribute to the breakdown of the blood-brain barrier seen in SVD. Hypertension, aging, metabolic syndrome, smoking, hyperglycemia, and elevated homocysteine may promote activation of NADPH oxidase in cerebral arterioles. Inhibition of NADPH oxidase with phycocyanobilin from spirulina, as well as high-dose statin therapy, may have potential for prevention and control of SVD, and high-potassium diets merit study in this regard. Measures which support effective eNOS activity in other ways-exercise training, supplemental citrulline, certain dietary flavonoids (as in cocoa and green tea), and capsaicin, may also improve the function of cerebral arterioles. Asian epidemiology suggests that increased protein intakes may decrease risk for SVD; conceivably, arginine and/or cysteine-which boosts tissue glutathione synthesis, and can be administered as N-acetylcysteine-mediate this benefit. Ameliorating the risk factors for SVD-including hypertension, metabolic syndrome, hyperglycemia, smoking, and elevated homocysteine-also may help to prevent and control this syndrome, although few clinical trials have addressed this issue to date.

ASSESSMENT OF LENS THICKNESS IN ANGLE CLOSURE DISEASE

Directory of Open Access Journals (Sweden)

Nishat Sultana Khayoom

2016-08-01

Full Text Available BACKGROUND Anterior chamber depth and lens thickness have been considered as important biometric determinants in primary angle-closure glaucoma. Patients with primary narrow angle may be classified as a primary angle closure suspect (PACS, or as having primary angle closure (PAC or primary angle closure glaucoma (PACG. 23.9% of patients with primary angle closure disease are in India, which highlights the importance of understanding the disease, its natural history, and its underlying pathophysiology, so that we may try to establish effective methods of treatment and preventative measures to delay, or even arrest, disease progression, thereby reducing visual morbidity. AIM To determine the lens thickness using A-scan biometry and its significance in various stages of angle closure disease. MATERIALS AND METHODS Patients attending outpatient department at Minto Ophthalmic Hospital between October 2013 to May 2015 were screened for angle closure disease and subsequently evaluated at glaucoma department. In our study, lens thickness showed a direct correlation with shallowing of the anterior chamber by determining the LT/ ACD ratio. A decrease in anterior chamber depth is proportional to the narrowing of the angle which contributes to the progression of the angle closure disease from just apposition to occlusion enhancing the risk for optic nerve damage and visual field loss. Hence, if the lens thickness values are assessed earlier in the disease process, appropriate intervention can be planned. CONCLUSION Determination of lens changes along with anterior chamber depth and axial length morphometrically can aid in early detection of angle closure. The role of lens extraction for PACG is a subject of increased interest. Lens extraction promotes the benefits of anatomical opening of the angle, IOP reduction and improved vision. This potential intervention may be one among the armamentarium of approaches for PACG. Among the current treatment modalities

Which soft lens power is better for piggyback in keratoconus? Part II.

Science.gov (United States)

Romero-Jiménez, Miguel; Santodomingo-Rubido, Jacinto; González-Meijóme, Jose-Manuel; Flores-Rodriguez, Patricia; Villa-Collar, Cesar

2015-02-01

To evaluate how soft lens power affects rigid gas-permeable (RGP) lens power and visual acuity (VA) in piggyback fittings for keratoconus. Sixteen keratoconus subjects (30 eyes) were included in the study. Piggyback contact lens fittings combining Senofilcon-A soft lenses of -6.00, -3.00, +3.00 and +6.00 D with Rose K2 RGP contact lenses were performed. Corneal topography was taken on the naked eye and over each soft contact lens before fitting RGP lenses. Mean central keratometry, over-refraction, RGP back optic zone radius (BOZR) and estimated final power as well as VA were recorded and analyzed. In comparison to the naked eye, the mean central keratometry flattened with both negative lens powers (psoft lens power (p=1.0); and steepened with the +6.00 soft lens power (p=0.02). Rigid gas-permeable over-refraction did not change significantly between different soft lens powers (all p>0.05). RGP's BOZR decreased significantly with both positive in comparison with both negative soft lens powers (all ppowers separately (both p>0.05). Estimated RGP's final power increased significantly with positive in comparison with negative lens powers (all ppowers separately (both p>0.05). Visual acuity did not change significantly between the different soft lens powers assessed (all p>0.05). The use of negative-powered soft lenses in piggyback fitting reduces RGP lens power without impacting VA in keratoconus subjects. Copyright © 2014 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Microbial contamination of soft contact lenses & accessories in asymptomatic contact lens users

Directory of Open Access Journals (Sweden)

Deeksha V Thakur

2014-01-01

Full Text Available Background & objectives: With increasing use of soft contact lenses the incidence of contact lens induced infections is also increasing. This study was aimed to assess the knowledge of new and existing contact lens users about the risk of microbial contamination associated with improper use and maintenance of contact lenses, type of microbial flora involved and their potential to cause ophthalmic infections. Methods: Four samples each from 50 participants (n=200 were collected from the lenses, lens care solutions, lens care solution bottles and lens cases along with a questionnaire regarding their lens use. The samples were inoculated onto sheep blood agar, Mac Conkey′s agar and Sabouraud′s dextrose agar. Organisms were identified using standard laboratory protocols. Results: Overall rate of microbial contamination among the total samples was 52 per cent. The most and the least contaminated samples were found to be lens cases (62% and lens care solution (42%, respectively. The most frequently isolated contaminant was Staphylococcus aureus (21% followed by Pseudomonas species (19.5%. Majority (64% of the participants showed medium grade of compliance to lens cleaning practices. Rate of contamination was 100 and 93.75 per cent respectively in those participants who showed low and medium compliance to lens care practices as compared to those who had high level of compliance (43.75% ( p0 <0.05. Interpretation & conclusions: Lens care practices amongst the participants were not optimum which resulted into high level contamination. Hence, creating awareness among the users about the lens care practices and regular cleaning and replacements of lens cases are required.

Effect of chronic smoking on lens nucleus as assessed by Pentacam HR lens densitometry in young adults.

Science.gov (United States)

Pekel, Gökhan; Cetin, Ebru Nevin; Acer, Semra; Yagci, Ramazan; Altintas, Seher; Ongun, Gülin Tugba

2014-06-01

To evaluate the effects of chronic tobacco smoking on lens nucleus by Pentacam HR lens densitometry (LD) in young adults. Prospective cross-sectional case series. Thirty subjects (23 M, 7 F) who were chronic cigarette smokers (≥10 cigarettes/day for at least 2 years) (group 1) and another 30 subjects (23 M, 7 F) who did not smoke (group 2), were included in this study. The patients were matched for age and sex between the groups. The exclusion criteria were any history of ocular surgery, any systemic disorders and any ocular diseases except for mild refractive disorders. Lens densitometry measurements were done with the Pentacam HR (Oculus, Wetzlar, Germany). The Schirmer test and pachymetry measurements were also performed. Mean age of the patients for both groups was 28.90 ± 8.20 years (range: 18-40 years). Mean lens densitometry (LD) measurements of Group 1 (chronic cigarette smoking group) were higher than those of Group 2 (control group) in all LD techniques; however only mean "peak" LD measurements showed a statistically significant difference between these two groups (Group 1: 8.67 ± 0.61, Group 2: 8.44 ± 0.70, p = 0.04). The mean Schirmer test value was 12.43 ± 5.60 mm in Group 1 and 13.00 ± 4.26 mm in Group 2 (p = 0.55). The mean central corneal thickness (CCT) value was 564.23 ± 34.61 µm in Group 1 and 550.47 ± 32.94 µm in Group 2 (p = 0.03). The Pentacam HR LD seems to be an important option for the evaluation of lens nucleus in young adults, because it gives objective and quantitative data. Although chronic smoking increases lens nucleus density in young adults, the effect is not statistically significant when compared with the control group.

A planar parabolic refractive nickel lens for high-energy X-rays

International Nuclear Information System (INIS)

Andrejczuk, Andrzej; Nagamine, Masaru; Sakurai, Yoshiharu; Itou, Masayoshi

2013-01-01

A compound refractive nickel lens focusing 174 keV X-rays to 5 µm with a gain of 4 is presented. A compound refractive lens made of nickel and designed for focusing high-energy synchrotron X-rays is presented. The lens consists of 600 parabolic grooves and focuses X-rays in one plane only (planar lens). The lenses made and investigated by us earlier exhibited low transmission and irregularities in the focused beam profile. Since then, improvements in lens manufacturing technology have been made. The present lens gives an almost Gaussian profile and produces four times higher intensity at its maximum compared with the intensity of primary X-ray beams of 174 keV

Design of a hyperbolic microwave metallic lens

International Nuclear Information System (INIS)

Uckan, T.

1979-12-01

Due to problems caused by multiple reflections in the cavity walls of the EBT fusion research device, the use of a horn becomes important for the directivity of waves in the millimetric range. An ordinary dielectric lens cannot be used because of plasma-wall interactions. Microwave metallic lenses, designed to focus the energy into a plane wave, can improve the directivity considerably. By implementing a 70-GHz standard-gain horn with a delay-type hyperbolic lens, which consists of a solid metallic disk with a number of equal size small holes has indicated a gain of 15 dB over the no lens case

3D printed helical antenna with lens

KAUST Repository

Farooqui, Muhammad Fahad

2016-12-19

The gain of an antenna can be enhanced through the integration of a lens, however this technique has traditionally been restricted to planar antennas due to fabrication limitations of standard manufacturing processes. Here, with a unique combination of 3D and 2D inkjet printing of dielectric and metallic inks respectively, we demonstrate a Fresnel lens that has been monolithically integrated to a non-planar antenna (helix) for the first time. Antenna measurements show that the integration of a Fresnel lens enhances the gain of a 2-turn helix by around 4.6 dB giving a peak gain of about 12.9 dBi at 8.8 GHz.

Magnetic lens apparatus for a low-voltage high-resolution electron microscope

Science.gov (United States)

Crewe, Albert V.

1996-01-01

A lens apparatus in which a beam of charged particles of low accelerating voltage is brought to a focus by a magnetic field, the lens being situated behind the target position. The lens comprises an electrically-conducting coil arranged around the axis of the beam and a magnetic pole piece extending along the axis of the beam at least within the space surrounded by the coil. The lens apparatus comprises the sole focusing lens for high-resolution imaging in a low-voltage scanning electron microscope.

NADPH oxidase activity in pollen tubes is affected by calcium ions, signaling phospholipids and Rac/Rop GTPases

Czech Academy of Sciences Publication Activity Database

Potocký, Martin; Pejchar, Přemysl; Gutkowska, Malgorzata; Jiménez-Quesada, M. J.; Potocká, Andrea; Alché, J.; Kost, B.; Žárský, Viktor

2012-01-01

Roč. 169, č. 16 (2012), s. 1654-1663 ISSN 0176-1617 R&D Projects: GA ČR GP522/09/P299 Institutional research plan: CEZ:AV0Z50380511 Keywords : Pollen tube * Tip growth * NADPH oxidase Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.699, year: 2012

Lens system for SIMS analysis

International Nuclear Information System (INIS)

Martinez, G.; Sancho, M.; Garcia-Galan, J.C.

1987-01-01

A powerful version of the charge-density method is applied to the study of a combined objective and emission lens, suitable for highly localized analysis of a flat sample surface. This lens can extract secondary ions of equal or opposite polarity to that of the primary particles. A computer simulation of the ion trajectories for both modes is made. The behaviour for different values of the geometric parameters and polarizations is analyzed and useful data for design such as primary beam demagnification and secondary image position are given. (author) 4 refs

Variable-focus liquid lens for portable applications

NARCIS (Netherlands)

Kuiper, S.; Hendriks, B.H.W.; Huijbregts, L.J.; Hirschberg, A.; Renders, C.A.; As, van M.A.J.; Mouroulis, P.Z.; Smith, W.J.; Johnson, R.B.

2004-01-01

The meniscus between two immiscible liquids can be used as an optical lens. A change in curvature of this meniscus by electrowetting leads to a change in focal distance. We demonstrate that two liquids in a tube form a self-centered tunable lens of high optical quality. Several properties were

21 CFR 886.4300 - Intraocular lens guide.

Science.gov (United States)

2010-04-01

...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4300 Intraocular lens guide. (a) Identification. An intraocular lens guide is a device intended to be inserted into the eye during surgery to direct... lenses, the device is exempt from the premarket notification procedures in subpart E of part 807 of this...

Treatment of contact lens related dry eye with antibacterial honey.

Science.gov (United States)

Wong, Daniel; Albietz, Julie M; Tran, Huan; Du Toit, Cimonette; Li, Anita Hui; Yun, Tina; Han, Jee; Schmid, Katrina L

2017-12-01

Contact lens induced dry eye affects approximately 50% of contact lens wearers. The aim was to assess the effects of Manuka (Leptospermum sp.) honey eye drops (Optimel, Melcare, Australia) on dry eye in contact lens wearers. The safety of the honey eye drops in contact lens wear and contact lens wearers' compliance were also evaluated. Prospective, randomised, cross over study, examiner masked, pilot treatment trial. Twenty-four participants aged 20 to 55 years with contact lens related dry eye were recruited and randomised to two treatment groups; 20 completed the study. One group used Optimel eye drops twice a day for two weeks followed by conventional lubricant (Systane Ultra, Alcon) therapy for two weeks; the other group completed the treatments in the reverse order. Before and after each treatment dry eye symptomology, ocular surface inflammation, and tear quantity and quality were assessed. Participants completed a daily log detailing their usage of treatments and any issues. Dry eye symptoms improved significantly after Optimel treatment. Patients with more severe symptoms at baseline showed a greater improvement in symptoms. No significant differences were observed in the objective signs of dry eye; presumably because of the short treatment duration. Seventy-five% of contact lens wearers reported good adherence to Optimel treatment and 95% reported no issues using this product. Optimel Eye Drops reduce the symptoms of dry eye in contact lens wearers and are safe to use. A longer treatment period to assess the effect on clinical signs of dry eye is required. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Gram negative bacteria and contact lens induced acute red eye

Directory of Open Access Journals (Sweden)

Sankaridurg Padmaja

1996-01-01

Full Text Available Two patients using hydrogel contact lenses on a daily wear schedule slept overnight with the lenses and woke up with a Contact Lens Induced Acute Red Eye (CLARE. The contact lenses recovered aseptically at the time of the event grew significant colonies of Pseudomonas aeruginosa and Aeromonas hydrophila in patient A and Pseudomonas aeruginosa and Serratia liquefaciens from patient B. Similar organisams from the contact lenses were recovered from the lens case and lens care solutions of patient B. In both the patients the condition resolved on discontinuation of lens wear. Patient compliance as a requirement for successful contact lens wear is highlighted with the illustration of these cases.

An all-silicone zoom lens in an optical imaging system

Science.gov (United States)

Zhao, Cun-Hua

2013-09-01

An all-silicone zoom lens is fabricated. A tunable metal ringer is fettered around the side edge of the lens. A nylon rope linking a motor is tied, encircling the notch in the metal ringer. While the motor is operating, the rope can shrink or release to change the focal length of the lens. A calculation method is developed to obtain the focal length and the zoom ratio. The testing is carried out in succession. The testing values are compared with the calculated ones, and they tally with each other well. Finally, the imaging performance of the all-silicone lens is demonstrated. The all-silicone lens has potential uses in cellphone cameras, notebook cameras, micro monitor lenses, etc.

Stimulus-dependent regulation of the phagocyte NADPH oxidase by a VAV1, Rac1, and PAK1 signaling axis

DEFF Research Database (Denmark)

Roepstorff, Kirstine; Rasmussen, Izabela Zorawska; Sawada, Makoto

2008-01-01

dominant-positive mutants enhanced, whereas dominant-negative mutants inhibited, NADPH oxidase-mediated superoxide generation following formyl-methionyl-leucylphenylalanine or phorbol 12-myristate 13-acetate stimulation. Both Rac1 and the GTP exchange factor VAV1 were required as upstream signaling......The p21-activated kinase-1 (PAK1) is best known for its role in the regulation of cytoskeletal and transcriptional signaling pathways. We show here in the microglia cell line Ra2 that PAK1 regulates NADPH oxidase (NOX-2) activity in a stimulus-specific manner. Thus, conditional expression of PAK1...... proteins in the formyl-methionyl-leucyl-phenylalanine-induced activation of endogenous PAK1. In contrast, PAK1 mutants had no effect on superoxide generation downstream of FcgammaR signaling during phagocytosis of IgG-immune complexes. We further present evidence that the effect of PAK1 on the respiratory...

Minimizing and measuring lens dose when giving cranial irradiation

International Nuclear Information System (INIS)

Woo, S.Y.; Donaldson, S.S.; Heck, R.J.; Nielson, K.L.; Shostak, C.

1989-01-01

Three different techniques of administering cranial irradiation were used to determine the dose to the lens as measured in the Rando phantom. The techniques employed were as follows: (1) the central axis of the radiation beam was placed at the thickest portion of the cranium; (2) the central axis of the radiation beam was placed at the lateral orbital rim (bon canthus); (3) the central axis of the radiation beam was placed at the thickest portion of the cranium but with the beam angled 5deg posteriorly away from the eye. Thermal luminescent dosimeters (TLD) were placed in a phantom, at a point determined from a life-sized anatomical section of the plane through the midsection of the eye, to be at the location of the posterior capsule of the lens. In addition, TLDs were placed on the outer surface of the phantom head, directly lateral to the location determined to be where the lens would lie. With equally weighted lateral opposed beams, delivering a midplane dose of 200cGy, the TLDs at the point of the lens measured 21, 9.9 and 10.6% of the midplane doses from the three techniques respectively. TLDs placed directly lateral to the lens on the surface of the phantom head gave an approximation of the lens dose, particularly when techniques 2 and 3 were used. Isodose curve generated by a General Electric treatment planning computer gave lens doses similar to those of the phantom data for each of the three different radiotherapy techniques. Cranial irradiation should be carried out by either technique 2 or technique 3 to minimize radiation dose to the lens. (author). 11 refs.; 2 figs.; 3 tabs

Qualification of a Null Lens Using Image-Based Phase Retrieval

Science.gov (United States)

Bolcar, Matthew R.; Aronstein, David L.; Hill, Peter C.; Smith, J. Scott; Zielinski, Thomas P.

2012-01-01

In measuring the figure error of an aspheric optic using a null lens, the wavefront contribution from the null lens must be independently and accurately characterized in order to isolate the optical performance of the aspheric optic alone. Various techniques can be used to characterize such a null lens, including interferometry, profilometry and image-based methods. Only image-based methods, such as phase retrieval, can measure the null-lens wavefront in situ - in single-pass, and at the same conjugates and in the same alignment state in which the null lens will ultimately be used - with no additional optical components. Due to the intended purpose of a Dull lens (e.g., to null a large aspheric wavefront with a near-equal-but-opposite spherical wavefront), characterizing a null-lens wavefront presents several challenges to image-based phase retrieval: Large wavefront slopes and high-dynamic-range data decrease the capture range of phase-retrieval algorithms, increase the requirements on the fidelity of the forward model of the optical system, and make it difficult to extract diagnostic information (e.g., the system F/#) from the image data. In this paper, we present a study of these effects on phase-retrieval algorithms in the context of a null lens used in component development for the Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission. Approaches for mitigation are also discussed.

Mechanism of mercuric chloride resistance in microorganisms. II. NADPH-dependent reduction of mercuric chloride and vaporization of mercury from mercuric chloride by a multiple drug resistant strain of Escherichia coli

Energy Technology Data Exchange (ETDEWEB)

Komura, I; Funaba, T; Izaki, K

1971-01-01

The activity to vaporize a /sup 203/Hg compound from /sup 203/HgCl/sub 2/ was demonstrated in crude cell-free extracts of a strain of Escherichia coli W2252, which had acquired the multiple drug resistance. NADPH was essential for the vaporization, while NADH had only a slight stimulating effect and NADP/sup +/ had no effect. The oxidation of NADPH dependent on HgCl/sub 2/ was also demonstrated in the crude extracts, but the HgCl/sub 2/-dependent NADH oxidation could be demonstrated only when a partially purified enzyme preparation was used. The rate of NADH oxidation was much slower than that of NADPH oxidation. It was concluded that NADPH, and to a lesser extent NADH, act as electron donors for the enzymatic reduction of HgCl/sub 2/ and the vaporization occurs after this reduction. This reduction and subsequent vaporization seem to provide a mechanism of resistance to HgCl/sub 2/ in E. coli strains having the multiple drug resistance. 15 references, 4 figures, 4 tables.

Plasmonic leak-free focusing lens under radially polarized illumination

International Nuclear Information System (INIS)

Li, Xiaowei; Tan, Qiaofeng; Bai, Benfeng; Jin, Guofan

2010-01-01

A plasmonic leak-free focusing lens with two asymmetric concentric ring slits under radially polarized illumination is proposed. Each ring slit in the plasmonic lens is designed to generate surface plasmon polaritons (SPPs) with a relative initial phase controlled by the ring slit parameters. Through mutual interference of the SPPs with different phases excited by the two concentric ring slits at the output metal–dielectric interface, the field intensity towards the center of the focusing lens can be enhanced while that leaking to the counter-focus direction is effectively suppressed. The optimal parameters of the plasmonic leak-free lens are theoretically obtained by satisfying the above condition and its focusing performance is demonstrated by numerical simulation. Furthermore, a plasmonic leak-free lens with multiple double-slit groups is proposed and discussed, which exhibits a higher energy density at the focusing spot of the output interface

Development of a 3D finite element model of lens microcirculation

Directory of Open Access Journals (Sweden)

Vaghefi Ehsan

2012-09-01

Full Text Available Abstract Background It has been proposed that in the absence of a blood supply, the ocular lens operates an internal microcirculation system. This system delivers nutrients, removes waste products and maintains ionic homeostasis in the lens. The microcirculation is generated by spatial differences in membrane transport properties; and previously has been modelled by an equivalent electrical circuit and solved analytically. While effective, this approach did not fully account for all the anatomical and functional complexities of the lens. To encapsulate these complexities we have created a 3D finite element computer model of the lens. Methods Initially, we created an anatomically-correct representative mesh of the lens. We then implemented the Stokes and advective Nernst-Plank equations, in order to model the water and ion fluxes respectively. Next we complemented the model with experimentally-measured surface ionic concentrations as boundary conditions and solved it. Results Our model calculated the standing ionic concentrations and electrical potential gradients in the lens. Furthermore, it generated vector maps of intra- and extracellular space ion and water fluxes that are proposed to circulate throughout the lens. These fields have only been measured on the surface of the lens and our calculations are the first 3D representation of their direction and magnitude in the lens. Conclusion Values for steady state standing fields for concentration and electrical potential plus ionic and fluid fluxes calculated by our model exhibited broad agreement with observed experimental values. Our model of lens function represents a platform to integrate new experimental data as they emerge and assist us to understand how the integrated structure and function of the lens contributes to the maintenance of its transparency.

Molecular cloning and functional characterization of NADPH-dependent cytochrome P450 reductase from the green microalga Botryococcus braunii, B race.

Science.gov (United States)

Tsou, Chung-Yau; Matsunaga, Shigeki; Okada, Shigeru

2018-01-01

The green microalga Botryococcus braunii of the B race accumulates various lipophilic compounds containing a 10,11-oxidosqualene epoxide moiety in addition to large amounts of triterpene hydrocarbons. While 2,3-squalene epoxidases have already been isolated and characterized from the alga, the enzyme that catalyzes the 10,11-epoxidation of squalene has remained elusive. In order to obtain a molecular tool to explore a 10,11-squalene epoxidase, cDNA cloning of an NADPH-dependent cytochrome P450 reductase (CPR) that is required by both squalene epoxidases and cytochrome P450 enzymes was carried out. The isolated cDNA contained an open reading frame (1998 bp) that encoded for a protein with 665 amino acid residues with a predicted molecular weight of 71.46 kDa and a theoretical pI of 5.49. Analysis of the deduced amino acid sequence revealed the presence of conserved motifs, including FMN, FAD, and NADPH binding domains, which are typical of other CPRs and necessary for enzyme activity. By truncation of the N-terminal transmembrane anchor and addition of a 6× His-tag, BbCPR was heterologously produced in Escherichia coli and purified by Ni-NTA affinity chromatography. The purified recombinant enzyme showed optimal reducing activity of cytochrome c at around a neutral pH at a temperature range of 30-37°C. For steady state kinetic parameters, the recombinant enzyme had a k m for cytochrome c and NADPH of 11.7±1.6 and 9.4±1.4 μM, and a k cat for cytochrome c and NADPH of 2.78±0.09 and 3.66±0.11 μmol/min/mg protein, respectively. This is the first study to perform the functional characterization of a CPR from eukaryotic microalgae. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Two-laser thermal-lens determination of phosphorus in silicon

International Nuclear Information System (INIS)

Grishko, V.I.; Gol'dshtein, M.M.; Grishko, V.P.; Yudelevich, I.G.

1986-01-01

Laser thermal-lens spectrophotometry is a high-sensitivity method of measuring absorptivity, where the signal is the relative intensity change at the beam center after passage through the medium, which absorbs at the laser wavelength. The two-lens method is discussed here which employs a high-power laser to induce the lens, while the absorptivity is measured from the intensity change in the beam from a continous wave low-power test laser at a wavelength different from that for the inducing one. This paper uses two-laser thermal-lens techniques to determine phosphorus in silicon. Phosphorus is determined as the ionic association of molybdophosphoric acid with auramine

[Phacoemulsification of subluxated lens with capsular tension ring implantation].

Science.gov (United States)

Dorecka, Mariola; Rokicki, Wojciech; Nita, Malgorzata; Krysik, Katarzyna; Nita, Ewa; Sikorska, Aleksandra; Romaniuk, Wanda

2007-01-01

To evaluate long term results of phacoemulsification with PC IOL and capsular tension ring (CTR) implantation in lens subluxation. The study comprised of 134 patients--146 eyes with subluxated lens. In all cases phacoemulsification with PC IOL and CTR implantation was performed. No intaroperative complications has occured. Postoperative complications included: inflammation in the anterior chamber in 3 eyes (2.1%), retinal detachment in 2 eyes (1.4%). In all cases there was no PC IOL decentration. (1) CTR facilitates phacoemulsification with PC IOL implantation in lens subluxation. (2) Phacoemulsification of subluxated lens with PC IOL and CTR implantation seems to be safe and effective procedure.

Improved integrating-sphere throughput with a lens and nonimaging concentrator.

Science.gov (United States)

Chenault, D B; Snail, K A; Hanssen, L M

1995-12-01

A reflectometer design utilizing an integrating sphere with a lens and nonimaging concentrator is described. Compared with previous designs where a collimator was used to restrict the detector field of view, the concentrator-lens combination significantly increases the throughput of the reflectometer. A procedure for designing lens-concentrators is given along with the results of parametric studies. The measured angular response of a lens-concentrator system is compared with ray-trace predictions and with the response of an ideal system.

Primary intraocular lens implantation for penetrating lens trauma in Africa.

Science.gov (United States)

Bowman, R J; Yorston, D; Wood, M; Gilbert, C; Foster, A

1998-09-01

This study aimed to audit the surgical strategy of primary posterior chamber intraocular lens implantation for cases of recent penetrating trauma involving the lens in an African population. Retrospective, noncomparative case series. Seventy-two cases are reported, including all patients who underwent primary intraocular lens implantation for traumatic cataract extraction performed within 1 month of injury between 1988 and 1996. Demographic characteristics and follow-up attendance rates are analyzed. Surgical technique and the occurrence of intraoperative and postoperative complications are reported. Visual outcomes are reported with detailed analysis for cases of poor visual outcome. Mean age was 14.3 years (standard deviation = 11.1), 57 (79%) were male and 15 (21%) were female (chi-square = 23.66, P capsule had been breached by the trauma in 27 (38%) cases, and 15 of these required anterior vitrectomy. Capsular fixation of the implant was achieved in 49% of patients, the remainder having sulcus fixation. Intraoperative rupture of the posterior capsule occurred in four cases. The only common postoperative complication was acute fibrinous anterior uveitis, which occurred in 29 (40%) patients, and 32% of patients followed up for at least 6 months required secondary posterior capsulotomy. This was more common in younger patients (chi-square = 4.2, P < 0.05). Corrected postoperative visual acuities were available for 51 patients, of which 71% achieved 20/60 or better visual acuity. Patients 6 years of age or younger were less likely to achieve 20/60 (chi-square = 6.61, P = 0.01). This surgical strategy has proved successful, producing good visual results and causing no sight-threatening complications. Primary posterior capsulotomy may be appropriate for younger patients.

Electronic states in a quantum lens

International Nuclear Information System (INIS)

Rodriguez, Arezky H.; Trallero-Giner, C.; Ulloa, S. E.; Marin-Antuna, J.

2001-01-01

We present a model to find analytically the electronic states in self-assembled quantum dots with a truncated spherical cap (''lens'') geometry. A conformal analytical image is designed to map the quantum dot boundary into a dot with semispherical shape. The Hamiltonian for a carrier confined in the quantum lens is correspondingly mapped into an equivalent operator and its eigenvalues and eigenfunctions for the corresponding Dirichlet problem are analyzed. A modified Rayleigh-Schro''dinger perturbation theory is presented to obtain analytical expressions for the energy levels and wave functions as a function of the spherical cap height b and radius a of the circular cross section. Calculations for a hard wall confinement potential are presented, and the effect of decreasing symmetry on the energy values and eigenfunctions of the lens-shape quantum dot is studied. As the degeneracies of a semicircular geometry are broken for b≠a, our perturbation approach allows tracking of the split states. Energy states and electronic wave functions with m=0 present the most pronounced influence on the reduction of the lens height. The method and expressions presented here can be straightforwardly extended to deal with more general Hamiltonians, including strains and valence-band coupling effects in Group III--V and Group II--VI self-assembled quantum dots

Forensic Analysis of a Contact Lens in a Murder Case.

Science.gov (United States)

Zwerling, Charles S

2016-03-01

Contact lenses have had rare relevance in trials and/or investigations. After 5 years of burial, orbital remnants were retrieved from an exhumed body and subsequently identified as a key piece of material evidence in a murder trial. The exhumed case materials were evaluated under laboratory conditions and were determined to be contact lens remnants. Contact lens fracture and burial simulation studies were performed to provide additional corroboration of the physical findings of the exhumed contact lens remnants. This material evidence was instrumental in providing factual proof refuting the defendant's testimony in the murder trial. A brief history of contact lens composition and use is provided for understanding the methods and observational results. This forensic case study represents the first published documentation of a contact lens from an exhumed body being used in a murder investigation and establishes an operational procedure for future forensic contact lens examinations. © 2016 American Academy of Forensic Sciences.

78 FR 18326 - Agency Information Collection Activities; Comment Request; Upward Bound and Upward Bound Math...

Science.gov (United States)

2013-03-26

...; Comment Request; Upward Bound and Upward Bound Math Science Annual Performance Report AGENCY: The Office... considered public records. Title of Collection: Upward Bound and Upward Bound Math Science Annual Performance...) and Upward Bound Math and Science (UBMS) Programs. The Department is requesting a new APR because of...

Chitah: Strong-gravitational-lens hunter in imaging surveys

Energy Technology Data Exchange (ETDEWEB)

Chan, James H. H.; Suyu, Sherry H.; Chiueh, Tzihong; More, Anupreeta; Marshall, Philip J.; Coupon, Jean; Oguri, Masamune; Price, Paul

2015-07-07

Strong gravitationally lensed quasars provide powerful means to study galaxy evolution and cosmology. Current and upcoming imaging surveys will contain thousands of new lensed quasars, augmenting the existing sample by at least two orders of magnitude. To find such lens systems, we built a robot, Chitah, that hunts for lensed quasars by modeling the configuration of the multiple quasar images. Specifically, given an image of an object that might be a lensed quasar, Chitah first disentangles the light from the supposed lens galaxy and the light from the multiple quasar images based on color information. A simple rule is designed to categorize the given object as a potential four-image (quad) or two-image (double) lensed quasar system. The configuration of the identified quasar images is subsequently modeled to classify whether the object is a lensed quasar system. We test the performance of Chitah using simulated lens systems based on the Canada–France–Hawaii Telescope Legacy Survey. For bright quads with large image separations (with Einstein radius ${r}_{\\mathrm{ein}}\\gt 1\\buildrel{\\prime\\prime}\\over{.} 1$) simulated using Gaussian point-spread functions, a high true-positive rate (TPR) of $\\sim 90\\%$ and a low false-positive rate of $\\sim 3\\%$ show that this is a promising approach to search for new lens systems. We obtain high TPR for lens systems with ${r}_{\\mathrm{ein}}\\gtrsim 0\\buildrel{\\prime\\prime}\\over{.} 5$, so the performance of Chitah is set by the seeing. We further feed a known gravitational lens system, COSMOS 5921+0638, to Chitah, and demonstrate that Chitah is able to classify this real gravitational lens system successfully. Our newly built Chitah is omnivorous and can hunt in any ground-based imaging surveys.

Compound refractive X-ray lens

International Nuclear Information System (INIS)

Nygren, D.R.; Cahn, R.; Cederstrom, B.; Danielsson, M.; Vestlund, J.

2000-01-01

An apparatus and method are disclosed for focusing X-rays. In one embodiment, his invention is a commercial-grade compound refractive X-ray lens. The commercial-grade compound refractive X-ray lens includes a volume of low-Z material. The volume of low-Z material has a first surface which is adapted to receive X-rays of commercially-applicable power emitted from a commercial-grade X-ray source. The volume of low-Z material also has a second surface from which emerge the X-rays of commercially-applicable power which were received at the first surface. Additionally, the commercial-grade compound refractive X-ray lens includes a plurality of openings which are disposed between the first surface and the second surface. The plurality of openings are oriented such that the X-rays of commercially-applicable power which are received at the first surface, pass through the volume of low-Z material and through the plurality openings. In so doing, the X-rays which emerge from the second surface are refracted to a focal point

Compound refractive X-ray lens

Science.gov (United States)

Nygren, David R.; Cahn, Robert; Cederstrom, Bjorn; Danielsson, Mats; Vestlund, Jonas

2000-01-01

An apparatus and method for focusing X-rays. In one embodiment, his invention is a commercial-grade compound refractive X-ray lens. The commercial-grade compound refractive X-ray lens includes a volume of low-Z material. The volume of low-Z material has a first surface which is adapted to receive X-rays of commercially-applicable power emitted from a commercial-grade X-ray source. The volume of low-Z material also has a second surface from which emerge the X-rays of commercially-applicable power which were received at the first surface. Additionally, the commercial-grade compound refractive X-ray lens includes a plurality of openings which are disposed between the first surface and the second surface. The plurality of openings are oriented such that the X-rays of commercially-applicable power which are received at the first surface, pass through the volume of low-Z material and through the plurality openings. In so doing, the X-rays which emerge from the second surface are refracted to a focal point.

Universal bounds on current fluctuations.

Science.gov (United States)

Pietzonka, Patrick; Barato, Andre C; Seifert, Udo

2016-05-01

For current fluctuations in nonequilibrium steady states of Markovian processes, we derive four different universal bounds valid beyond the Gaussian regime. Different variants of these bounds apply to either the entropy change or any individual current, e.g., the rate of substrate consumption in a chemical reaction or the electron current in an electronic device. The bounds vary with respect to their degree of universality and tightness. A universal parabolic bound on the generating function of an arbitrary current depends solely on the average entropy production. A second, stronger bound requires knowledge both of the thermodynamic forces that drive the system and of the topology of the network of states. These two bounds are conjectures based on extensive numerics. An exponential bound that depends only on the average entropy production and the average number of transitions per time is rigorously proved. This bound has no obvious relation to the parabolic bound but it is typically tighter further away from equilibrium. An asymptotic bound that depends on the specific transition rates and becomes tight for large fluctuations is also derived. This bound allows for the prediction of the asymptotic growth of the generating function. Even though our results are restricted to networks with a finite number of states, we show that the parabolic bound is also valid for three paradigmatic examples of driven diffusive systems for which the generating function can be calculated using the additivity principle. Our bounds provide a general class of constraints for nonequilibrium systems.

In vivo study of lens regeneration in Rana cyanophlyctis under ...

African Journals Online (AJOL)

SAM

2014-03-12

Mar 12, 2014 ... enhanced the percentage lens regeneration not only in young tadpoles but also in froglets. Lens regeneration ability ... Influence of vitamin A and ascorbic acid on lens regeneration in young, mature tadpoles and froglets of the frog Rana cyanophlyctis. Group .... ingested by macrophages. Dorsal iris cells ...

Color corrected Fresnel lens for solar concentration

International Nuclear Information System (INIS)

Kritchman, E.M.

1979-01-01

A new linear convex Fresnel lens with its groove side down is described. The design philosophy is similar to the highly concentrating two focal Fresnel lens but including a correction for chromatic aberration. A solar concentration ratio as high as 80 is achieved. For wide acceptance angles the concentration nears the theoretical maximum. (author)

The significance of oxygen during contact lens wear.

Science.gov (United States)

Papas, Eric B

2014-12-01

In order to establish the relevance of oxygen to contemporary contact lens practice, a review of the literature was conducted. The results indicate that there are a number of processes occurring in the normal healthy eye where oxygen is required and which are potentially affected by the presence of a contact lens. These activities appear to take place at all corneal levels, as well as at the limbus. Evidence from laboratory, clinical and modelling studies indicates that what constitutes normal oxygenation (normoxia) depends on, among other things, the physiological system under consideration, corneal location and the state of eye closure. This diversity is reflected in the wide range of minimum lens oxygen transmissibility (Dk/t) requirements that are present in a literature. Copyright © 2014 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

An acoustic Maxwell’s fish-eye lens based on gradient-index metamaterials

International Nuclear Information System (INIS)

Yuan Bao-guo; Tian Ye; Cheng Ying; Liu Xiao-jun

2016-01-01

We have proposed a two-dimensional acoustic Maxwell’s fish-eye lens by using the gradient-index metamaterials with space-coiling units. By adjusting the structural parameters of the units, the refractive index can be gradually varied, which is key role to design the acoustic fish-eye lens. As predicted by ray trajectories on a virtual sphere, the proposed lens has the capability to focus the acoustic wave irradiated from a point source at the surface of the lens on the diametrically opposite side of the lens. The broadband and low loss performance is further demonstrated for the lens. The proposed acoustic fish-eye lens is expected to have the potential applications in directional acoustic coupler or coherent ultrasonic imaging. (paper)

Variable wide range of lens power and its improvement in a liquid-crystal lens using highly resistive films divided into two regions with different diameters

Science.gov (United States)

Kawamura, Marenori; Sato, Susumu

2018-05-01

The variable range of lens power of a liquid-crystal (LC) lens driven by two voltages is discussed on the basis of calculated and experimental results. The LC lens has two electrodes, which are a circularly hole-patterned electrode and a circular electrode, in addition to a common electrode, and highly resistive transparent films. The variable range of lens power increases with increasing driving voltage applied across the circularly hole-patterned electrode and the common electrode, and with decreasing diameter of highly resistive films. However, the optical-phase retardation profile tends to deviate from a parabolic curve in these cases. As a method to improve the trade-off properties, the highly resistive film is divided into two regions with different diameters, where the sheet resistance of an outer film is larger than that of an inner one. The improved LC lens has a lens power that varies in a wide range, and it exhibits a good parabolic phase retardation profile.

Corneal ring infiltration in contact lens wearers

Directory of Open Access Journals (Sweden)

Seyed Ali Tabatabaei

2017-01-01

Full Text Available To report a case of atypical sterile ring infiltrates during wearing soft silicone hydrogel contact lens due to poor lens care. A 29-year-old woman presented with complaints of pain, redness, and morning discharge. She was wearing soft silicone hydrogel contact lens previously; her current symptoms began 1 week before presentation. On examination, best-corrected visual acuity was 20/40 in that eye. Slit-lamp examination revealed dense, ring-shaped infiltrate involving both the superficial and deep stromal layers with lucid interval to the limbus, edema of the epithelium, epithelial defect, and vascularization of the superior limbus. Cornea-specific in vivo laser confocal microscopy (Heidelberg Retina Tomograph 2 Rostock Cornea Module, HRT 2-RCM, Heidelberg Engineering GmbH, Dossenheim, Germany revealed Langerhans cells and no sign of Acanthamoeba or fungal features, using lid scraping and anti-inflammatory drops; her vision completely recovered. We reported an atypical case of a sterile corneal ring infiltrate associated with soft contact lens wearing; smear, culture, and confocal microscopy confirmed a sterile inflammatory reaction.

The gravitational lens effect and its optical equivalents

International Nuclear Information System (INIS)

Freitas, L.R. de.

1987-01-01

This work presents the evolution of the use of the so called gravitational lens effect from a simple observational teste of the General Relativity theory to an instrument to measure cosmological parameters. A detailed analysis of how a gravitational ''lens'' deflects light without forming images is shown for the case of the deflector with spherical symmetry. In addition, the exact optical equivalent of a cylindrical gravitational lens, which forms true images, is proposed. Finally the problem of the formation of multiple images and the related astronomical observations is discussed. (author) [pt

Multiplexing schemes for an achromatic programmable diffractive lens

Energy Technology Data Exchange (ETDEWEB)

Millan, M S; Perez-Cabre, E; Oton, J [Technical University of Catalonia, Dep. Optics and Optometry, Terrassa-Barcelona, 08222 (Spain)], E-mail: millan@oo.upc.edu

2008-11-01

A multiplexed programmable diffractive lens, displayed on a pixelated liquid crystal device under broadband illumination, is proposed to compensate for the severe chromatic aberration that affects diffractive elements. The proposed lens is based on multiplexing a set of sublenses with a common focal length for different wavelengths. We consider different types of integration of the optical information (spatial only, temporal only and hybrid spatial-temporal) combined with a proper selection of the spectral bandwidth. The properties and limits of the achromatic programmable multiplexed lens are described. Experimental results are presented and discussed.

Multiplexing schemes for an achromatic programmable diffractive lens

International Nuclear Information System (INIS)

Millan, M S; Perez-Cabre, E; Oton, J

2008-01-01

A multiplexed programmable diffractive lens, displayed on a pixelated liquid crystal device under broadband illumination, is proposed to compensate for the severe chromatic aberration that affects diffractive elements. The proposed lens is based on multiplexing a set of sublenses with a common focal length for different wavelengths. We consider different types of integration of the optical information (spatial only, temporal only and hybrid spatial-temporal) combined with a proper selection of the spectral bandwidth. The properties and limits of the achromatic programmable multiplexed lens are described. Experimental results are presented and discussed.

Repertoire of free-living protozoa in contact lens solutions.

Science.gov (United States)

Bouchoucha, Ibtissem; Aziz, Aurore; Hoffart, Louis; Drancourt, Michel

2016-10-29

The repertoire of free-living protozoa in contact lens solutions is poorly known despite the fact that such protozoa may act as direct pathogens and may harbor intra-cellular pathogens. Between 2009 and 2014, the contact lens solutions collected from patients presenting at our Ophthalmology Department for clinically suspected keratitis, were cultured on non-nutrient agar examined by microscope for the presence of free-living protozoa. All protozoa were identified by 18S rRNA gene sequencing. A total of 20 of 233 (8.6 %) contact lens solution specimens collected from 16 patients were cultured. Acanthamoeba amoeba in 16 solutions (80 %) collected from 12 patients and Colpoda steini, Cercozoa sp., Protostelium sp. and a eukaryotic more closely related to Vermamoeba sp., were each isolated in one solution. Cercozoa sp., Colpoda sp., Protostelium sp. and Vermamoeba sp. are reported for the first time as contaminating contact lens solutions. The repertoire of protozoa in contact lens solutions is larger than previously known.

Quivers of Bound Path Algebras and Bound Path Coalgebras

Directory of Open Access Journals (Sweden)

Dr. Intan Muchtadi

2010-09-01

Full Text Available bras and coalgebras can be represented as quiver (directed graph, and from quiver we can construct algebras and coalgebras called path algebras and path coalgebras. In this paper we show that the quiver of a bound path coalgebra (resp. algebra is the dual quiver of its bound path algebra (resp. coalgebra.

Design of a nonimaging Fresnel lens for solar concentrators

Energy Technology Data Exchange (ETDEWEB)

Leutz, R.; Akisawa, Atushi; Kashiwagi, Takao [Tokyo University of Agriculture and Technology (Japan). Dept. of Mechanical Systems Engineering; Suzuki, Akio [UNESCO, Paris (France)

1999-04-01

An optimum convex shaped nonimaging Fresnel lens is designed following the edge ray principle. The lens is evaluated by tracing rays and calculating a projective optical concentration ratio. This Fresnel lens is intended for use in evacuated tube type solar concentrators, generating mid-temperature heat to drive sorption cycles, or provide industrial process heat. It can also be used along with a secondary concentrator in photovoltaic applications. (author)

Lens autofluorescence is not increased at high altitude

DEFF Research Database (Denmark)

Kessel, Line; Kofoed, Peter Kristian; Zubieta-Calleja, Gustavo

2010-01-01

in Denmark. RESULTS: No significant differences in lens fluorescence or transmittance were found between Bolivian and Danish volunteers. CONCLUSION: Age-corrected lens fluorescence and transmittance were comparable for healthy participants living at high altitude near the equator and healthy volunteers...

Isofocusing and immunological investigations on cephalopod lens proteins

NARCIS (Netherlands)

Brahma, S.K.; Lancieri, M.

1979-01-01

Soluble lens proteins from Octopus vulgaris, Sepia officinalis, and Loligo vulgaris were analyzed by thin-layer isoelectric focusing and compared by various immunochemical methods using antibodies directed against total soluble lens protein antigens from the said three species. The results show

Research progress on the measurement of human lens thickness in vivo

Directory of Open Access Journals (Sweden)

Yu-Huan Yang

2017-05-01

Full Text Available The precise measurement in lens thickness in vivo, provides great application value for intraocular accommodation and ametropia development mechanism research. And it has great clinical significance for the diagnosis and treatment of glaucoma and cataract. Currently, many ultrasonic methods and optical methods are used in measuring lens thickness. The measurement principles, advantages, disadvantages and the accuracy of the instruments are summarized in this paper. Among these methods, Orbscan II, Pentacam, Lenstar and AS-OCT can be used to measure lens thickness instead of A-scan. More important is the fact that UL-OCT can dynamically monitor the change of the lens thickness with intraocular accommodation. Choosing an instrument with higher measuring accuracy to examine the lens thickness, can provide more accurate and convincing lens thickness data for clinical and scientific research.

Infrared observations of the dark matter lens candidate Q2345+007

Science.gov (United States)

Mcleod, Brian; Rieke, Marcia; Weedman, Daniel

1994-01-01

Deep K-band observations are presented of the double image quasar Q2345+007. This has the largest separation (7.1 sec) of any quasar image pair considered as gravitationally lensed, so the required lens is massive (10(exp 13) solar masses). No lens has been detected in previous deep images at visible wavelengths, and we find no lens to limiting K magnitude 20.0 in the infrared image. This constrains any lens to being much less luminous than brightest cluster galaxies, while the lens must be much more massive than such galaxies to produce the observed separation. Because spectral data indicate exceptional intrinsic similarity in the quasar image components, this pair remains as the most intriguing example of an observed configuration requiring the presence of massive, concentrated dark matter acting as a gravitational lens.

Severe pigment dispersion after iris-claw phakic intraocular lens implantation.

Science.gov (United States)

Galvis, Virgilio; Carreño, Néstor I; Tello, Alejandro; Laiton, Andrea N

2017-12-01

A 23-year-old female patient presented 3 months after the implantation of an Artisan® phakic intraocular lens with a severe depigmentation of the iris and peripheral anterior synechiae. Explantation of the intraocular lens and goniosynechialysis were performed. Eleven months after the explantation appearance of the iris significantly improved. There was no loss of lines of corrected distance visual acuity. Severe pigment dispersion after the implantation of an Artisan® phakic intraocular lens may happen and may require explantation of the lens. Iris depigmentation may improve with time.

Severe pigment dispersion after iris-claw phakic intraocular lens implantation

Directory of Open Access Journals (Sweden)

Virgilio Galvis

2017-01-01

Full Text Available A 23-year-old female patient presented 3 months after the implantation of an Artisan® phakic intraocular lens with a severe depigmentation of the iris and peripheral anterior synechiae. Explantation of the intraocular lens and goniosynechialysis were performed. Eleven months after the explantation appearance of the iris significantly improved. There was no loss of lines of corrected distance visual acuity. Severe pigment dispersion after the implantation of an Artisan® phakic intraocular lens may happen and may require explantation of the lens. Iris depigmentation may improve with time.

Intracellular expression of reactive oxygen species-generating NADPH oxidase NOX4 in normal and cancer thyroid tissues

NARCIS (Netherlands)

Weyemi, Urbain; Caillou, Bernard; Talbot, Monique; Ameziane-El-Hassani, Rabii; Lacroix, Ludovic; Lagent-Chevallier, Odile; Al Ghuzlan, Abir; Roos, Dirk; Bidart, Jean-Michel; Virion, Alain; Schlumberger, Martin; Dupuy, Corinne

2010-01-01

NADPH oxidase 4 (NOX4) belongs to the NOX family that generates reactive oxygen species (ROS). Function and tissue distribution of NOX4 have not yet been entirely clarified. To date, in the thyroid gland, only DUOX1/2 NOX systems have been described. NOX4 mRNA expression, as shown by real-time PCR,

Cytokine changes in tears and relationship to contact lens discomfort.

Science.gov (United States)

Willcox, Mark D P; Zhao, Zhenjun; Naduvilath, Thomas; Lazon de la Jara, Percy

2015-01-01

To determine the reproducibility of a multiplex bead assay for measuring cytokines in tears and correlations between ocular discomfort with or without contact lens wear and the concentration of cytokines in tears. Ninety participants (divided into two groups) were enrolled in this prospective study. They were asked to rate their ocular comfort and collect their tears in the morning and just before sleep for 10 days with or without contact lenses. The participants collected their tears using a glass microcapillary tube for both stages. Galyfilcon A lenses were worn on a daily disposable basis during the contact lens stage, and comfort scores and tears were collected before lens insertion and prior to lens removal at the end of the day. Tears were analyzed for cytokine concentrations using a 27-plex multibead assay. Correlations were sought between cytokine concentrations and comfort. There was a significant (p-0.5 Log pg/ml, p-0.2 Log pg/ml, ptears was correlated to ocular comfort, but this was not changed by contact lens wear. Ocular comfort during the day is magnified by contact lens wear. However, the increase in the change in comfort during lens wear was not associated with changes in 15 cytokines in the tear film.

Eye lens radiation exposure in Greek interventional cardiology personnel

International Nuclear Information System (INIS)

Thrapsanioti, Zoi; Askounis, Panagiotis; Carinou, Eleftheria; Datseris, Ioannis; Diamanti, Ramza Anastasia; Papathanasiou, Miltiadis

2017-01-01

The lens of the eye is one of the radiosensitive tissues of the human body; if exposed to ionizing radiation can develop radiation-induced cataract at early ages. This study was held in Greece and included 44 Interventional Cardiologists (ICs) and an unexposed to radiation control group of 22 persons. Of the note, 26 ICs and the unexposed individuals underwent special eye examinations. The detected lens opacities were classified according to LOCS III protocol. Additionally, the lens doses of the ICs were measured using eye lens dosemeters. The mean dose to the lenses of the ICs per month was 0.83 ± 0.59 mSv for the left and 0.35 ± 0.38 mSv for the right eye, while the annual doses ranged between 0.7 and 11 mSv. Regarding the lens opacities, the two groups did not differ significantly in the prevalence of either nuclear or cortical lens opacities, whereas four ICs were detected with early stage subcapsular sclerosis. Though no statistically difference was observed in the cohort, the measured doses indicate that the eye doses received from the ICs can be significant. To minimize the radiation-induced risk at the eye lenses, the use of protective equipment and appropriate training on this issue is highly recommended. (authors)

Ocular surface and tear film status among contact lens wearers and non-wearers who use VDT at work: comparing three different lens types.

Science.gov (United States)

Tauste, Ana; Ronda, Elena; Baste, Valborg; Bråtveit, Magne; Moen, Bente E; Seguí Crespo, María-Del-Mar

2018-04-01

To analyze differences in the ocular surface appearance and tear film status of contact lens wearers and non-wearers in a group of visual display terminals (VDT) workers and additionally to assess differences between lens materials. Cross-sectional study of 236 office workers, of whom 92 were contact lens wearers. Workers provided information on their contact lenses (conventional hydrogel, silicone hydrogel or rigid gas permeable lenses) and exposure to VDT at work. Ocular surface and tear film status were determined by the presence of bulbar, limbal and lid redness, lid roughness and corneal staining type, and by Schirmer's and tear break-up time tests (TBUT). A generalized linear model was used to calculate the crude (cRR) and age- and sex-adjusted (aRR) relative risk to measure the association between ocular surface and tear film abnormalities and contact lens use and type. The aRR of ocular surface abnormalities was higher in contact lens wearers compared to non-wearers: bulbar redness (aRR 1.69; 95% CI 1.25-2.30), limbal redness (aRR 2.87; 1.88-4.37), lid redness (aRR 2.53; 1.35-4.73) and lid roughness (aRR 7.03; 1.31-37.82). VDT exposure > 4 h/day increased wearers' risk of limbal and lid redness. Conventional hydrogel wearers had the highest risk of ocular surface abnormalities, followed by silicone hydrogel wearers. Both contact and non-contact lens wearers had a high prevalence of altered TBUT (77.3 and 75.7% respectively) and Schirmer (51.8 and 41.3%). Regular contact lens use during VDT exposure at work increases risk of bulbar, limbal and lid redness, and lid roughness, especially in soft contact lens wearers. The high prevalence of altered TBUT and Schirmer's results in all participants suggests that VDT use greatly affects tear film characteristics.

Apocynin: Chemical and Biophysical Properties of a NADPH Oxidase Inhibitor

Directory of Open Access Journals (Sweden)

Valdecir F. Ximenes

2013-03-01

Full Text Available Apocynin is the most employed inhibitor of NADPH oxidase (NOX, a multienzymatic complex capable of catalyzing the one-electron reduction of molecular oxygen to the superoxide anion. Despite controversies about its selectivity, apocynin has been used as one of the most promising drugs in experimental models of inflammatory and neurodegenerative diseases. Here, we aimed to study the chemical and biophysical properties of apocynin. The oxidation potential was determined by cyclic voltammetry (Epa = 0.76V, the hydrophobicity index was calculated (logP = 0.83 and the molar absorption coefficient was determined (e275nm = 1.1 × 104 M−1 cm−1. Apocynin was a weak free radical scavenger (as measured using the DPPH, peroxyl radical and nitric oxide assays when compared to protocatechuic acid, used here as a reference antioxidant. On the other hand, apocynin was more effective than protocatechuic acid as scavenger of the non-radical species hypochlorous acid. Apocynin reacted promptly with the non-radical reactive species H2O2 only in the presence of peroxidase. This finding is relevant, since it represents a new pathway for depleting H2O2 in cellular experimental models, besides the direct inhibition of NADPH oxidase. This could be relevant for its application as an inhibitor of NOX4, since this isoform produces H2O2 and not superoxide anion. The binding parameters calculated by fluorescence quenching showed that apocynin binds to human serum albumin (HSA with a binding affinity of 2.19 × 104 M−1. The association did not alter the secondary and tertiary structure of HSA, as verified by synchronous fluorescence and circular dichroism. The displacement of fluorescent probes suggested that apocynin binds to site I and site II of HSA. Considering the current biomedical applications of this phytochemical, the dissemination of these chemical and biophysical properties can be very helpful for scientists and physicians interested in the use of apocynin.

Evolution and the Calcite Eye Lens

OpenAIRE

Williams, Vernon L.

2013-01-01

Calcite is a uniaxial, birefringent crystal, which in its optically transparent form, has been used for animal eye lenses, the trilobite being one such animal. Because of the calcite birefringence there is a difficulty in using calcite as a lens. When the propagation direction of incoming light is not exactly on the c-axis, the mages blur. In this paper, calcite blurring is evaluated, and the non-blurring by a crystallin eye lens is compared to a calcite one.

An all-silicone zoom lens in an optical imaging system

International Nuclear Information System (INIS)

Zhao Cun-Hua

2013-01-01

An all-silicone zoom lens is fabricated. A tunable metal ringer is fettered around the side edge of the lens. A nylon rope linking a motor is tied, encircling the notch in the metal ringer. While the motor is operating, the rope can shrink or release to change the focal length of the lens. A calculation method is developed to obtain the focal length and the zoom ratio. The testing is carried out in succession. The testing values are compared with the calculated ones, and they tally with each other well. Finally, the imaging performance of the all-silicone lens is demonstrated. The all-silicone lens has potential uses in cellphone cameras, notebook cameras, micro monitor lenses, etc. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Differentially regulated NADPH:cytochrome P450 oxidoreductases in parsley

Science.gov (United States)

Koopmann, Edda; Hahlbrock, Klaus

1997-01-01

Two NADPH:cytochrome P450 oxidoreductases (CPRs) from parsley (Petroselinum crispum) were cloned, and the complete proteins were expressed and functionally identified in yeast. The two enzymes, designated CPR1 and CPR2, are 80% identical in amino acid sequence with one another and about 75% identical with CPRs from several other plant species. The mRNA accumulation patterns for CPR1 and CPR2 in fungal elicitor-treated or UV-irradiated cultured parsley cells and in developing or infected parsley plants were compared with those for cinnamate 4-hydroxylase (C4H), one of the most abundant CPR-dependent P450 enzymes in plants. All treatments strongly induced the mRNAs for C4H and CPR1 but not for CPR2, suggesting distinct metabolic roles of CPR1 and CPR2 and a functional relationship between CPR1 and C4H. PMID:9405720

Differentially regulated NADPH: cytochrome p450 oxidoreductases in parsely

International Nuclear Information System (INIS)

Koopmann, E.; Hahlbrock, K.

1997-01-01

Two NADPH:cytochrome P450 oxidoreductases (CPRs) from parsley (Petroselinum crispum) were cloned, and the complete proteins were expressed and functionally identified in yeast. The two enzymes, designated CPR1 and CPR2, are 80% identical in amino acid sequence with one another and about 75% identical with CPRs from several other plant species. The mRNA accumulation patterns for CPR1 and CPR2 in fungal elicitor-treated or UV-irradiated cultured parsley cells and in developing or infected parsley plants were compared with those for cinnamate 4-hydroxylase (C4H), one of the most abundant CPR-dependent P450 enzymes in plants. All treatments strongly induced the mRNAs for C4H and CPR1 but not for CPR2, suggesting distinct metabolic roles of CPR1 and CPR2 and a functional relationship between CPR1 and C4H

NADPH Oxidase Activity in Cerebral Arterioles Is a Key Mediator of Cerebral Small Vessel Disease—Implications for Prevention

Directory of Open Access Journals (Sweden)

Mark F. McCarty

2015-04-01

Full Text Available Cerebral small vessel disease (SVD, a common feature of brain aging, is characterized by lacunar infarcts, microbleeds, leukoaraiosis, and a leaky blood-brain barrier. Functionally, it is associated with cognitive decline, dementia, depression, gait abnormalities, and increased risk for stroke. Cerebral arterioles in this syndrome tend to hypertrophy and lose their capacity for adaptive vasodilation. Rodent studies strongly suggest that activation of Nox2-dependent NADPH oxidase activity is a crucial driver of these structural and functional derangements of cerebral arterioles, in part owing to impairment of endothelial nitric oxide synthase (eNOS activity. This oxidative stress may also contribute to the breakdown of the blood-brain barrier seen in SVD. Hypertension, aging, metabolic syndrome, smoking, hyperglycemia, and elevated homocysteine may promote activation of NADPH oxidase in cerebral arterioles. Inhibition of NADPH oxidase with phycocyanobilin from spirulina, as well as high-dose statin therapy, may have potential for prevention and control of SVD, and high-potassium diets merit study in this regard. Measures which support effective eNOS activity in other ways—exercise training, supplemental citrulline, certain dietary flavonoids (as in cocoa and green tea, and capsaicin, may also improve the function of cerebral arterioles. Asian epidemiology suggests that increased protein intakes may decrease risk for SVD; conceivably, arginine and/or cysteine—which boosts tissue glutathione synthesis, and can be administered as N-acetylcysteine—mediate this benefit. Ameliorating the risk factors for SVD—including hypertension, metabolic syndrome, hyperglycemia, smoking, and elevated homocysteine—also may help to prevent and control this syndrome, although few clinical trials have addressed this issue to date.

Effects of co-administration of dietary sodium arsenite and an NADPH oxidase inhibitor on the rat bladder epithelium

International Nuclear Information System (INIS)

Suzuki, Shugo; Arnold, Lora L.; Pennington, Karen L.; Kakiuchi-Kiyota, Satoko; Cohen, Samuel M.

2009-01-01

Arsenite (As III ), an inorganic arsenical, is a known human carcinogen, inducing tumors of the skin, urinary bladder and lung. It is metabolized to organic methylated arsenicals. Oxidative stress has been suggested as a mechanism for arsenic-induced carcinogenesis. Reactive oxygen species (ROS) can be important factors for carcinogenesis and tumor progression. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is known to produce intracellular ROS, therefore, we investigated the ability of apocynin (acetovanillone), an NADPH oxidase inhibitor, to inhibit the cytotoxicity and regenerative cell proliferation of arsenic in vitro and in vivo. Apocynin had similar effects in reducing the cytotoxicity of As III and dimethylarsinous acid (DMA III ) in rat urothelial cells in vitro. When tested at the same concentrations as apocynin, other antioxidants, such as L-ascorbate and N-acetylcysteine, did not inhibit As III -induced cytotoxicity but they were more effective at inhibiting DMA III -induced cytotoxicity compared with apocynin. In vivo, female rats were treated for 3 weeks with 100 ppm As III . Immunohistochemical staining for 8-hydroxy-2'-deoxyguanosine (8-OHdG) showed that apocynin reduced oxidative stress partially induced by As III treatment on rat urothelium, and significantly reduced the cytotoxicity of superficial cells detected by scanning electron microscopy (SEM). However, based on the incidence of simple hyperplasia and the bromodeoxyuridine (BrdU) labeling index, apocynin did not inhibit As III -induced urothelial cell proliferation. These data suggest that the NADPH oxidase inhibitor, apocynin, may have the ability to partially inhibit arsenic-induced oxidative stress and cytotoxicity of the rat bladder epithelium in vitro and in vivo. However, apocynin did not inhibit the regenerative cell proliferation induced by arsenite in a short-term study.

Hyperelastic modelling of the crystalline lens: Accommodation and presbyopia

Science.gov (United States)

Lanchares, Elena; Navarro, Rafael; Calvo, Begoña

2012-01-01

Purpose The modification of the mechanical properties of the human crystalline lens with age can be a major cause of presbyopia. Since these properties cannot be measured in vivo, numerical simulation can be used to estimate them. We propose an inverse method to determine age-dependent change in the material properties of the tissues composing the human crystalline lens. Methods A finite element model of a 30-year-old lens in the accommodated state was developed. The force necessary to achieve full accommodation in a 30-year-old lens of known external geometry was computed using this model. Two additional numerical models of the lens corresponding to the ages of 40 and 50 years were then built. Assuming that the accommodative force applied to the lens remains constant with age, the material properties of nucleus and cortex were estimated by inverse analysis. Results The zonular force necessary to reshape the model of a 30-year-old lens from the accommodated to the unaccommodated geometry was 0.078 newton (N). Both nucleus and cortex became stiffer with age. The stiffness of the nucleus increased with age at a higher rate than the cortex. Conclusions In agreement with the classical theory of Helmholtz, on which we based our model, our results indicate that a major cause of presbyopia is that both nucleus and cortex become stiffer with age; therefore, a constant value of the zonular forces with aging does not achieve full accommodation, that is, the accommodation capability decreases.

Lens Dk/t influences the clinical response in overnight orthokeratology.

Science.gov (United States)

Lum, Edward; Swarbrick, Helen A

2011-04-01

To investigate the influence of lens oxygen transmissibility (Dk/t) on the clinical response to overnight (ON) orthokeratology (OK) lens wear over 2 weeks. Eleven subjects (age, 20 to 39 years) were fitted with OK lenses (BE; Capricornia Contact Lens) in both eyes. Lenses in matched design/fitting but different materials (Boston EO and XO; nominal Dk/t: 26 and 46 ISO Fatt, respectively) were worn ON only in the two eyes over a 2-week period. Changes in logarithm of the minimum angle of resolution visual acuity, subjective refraction (spherical equivalent), corneal apical radius ro and asphericity Q (Medmont E300), and central stromal thickness (Holden-Payor optical pachometer) were measured. There were statistically significant differences in outcomes between the two lens materials (analysis of variance, p 0.05). An increase in lens Dk/t appears to increase the clinical effects of ON reverse-geometry lens wear over the medium term. This adds further support to the recommendation that high Dk materials should be used for ON OK not only to provide physiological advantages but also to optimize clinical outcomes.

β1-integrin controls cell fate specification in early lens development

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Pathania, Mallika; Wang, Yan; Simirskii, Vladimir N.; Duncan, Melinda K.

2016-01-01

Integrins are heterodimeric cell surface molecules that mediate cell-extracellular matrix (ECM) adhesion, ECM assembly, and regulation of both ECM and growth factor induced signaling. However, the developmental context of these diverse functions is not clear. Loss of β1-integrin from the lens vesicle (mouse E10.5) results in abnormal exit of anterior lens epithelial cells (LECs) from the cell cycle and their aberrant elongation toward the presumptive cornea by E12.5. These cells lose expression of LEC markers and initiate expression of the Maf (also known as c-Maf) and Prox1 transcription factors as well as other lens fiber cell markers, β1-integrin null LECs also upregulate the ERK, AKT and Smad1/5/8 phosphorylation indicative of BMP and FGF signaling. By E14.5, β1-integrin null lenses have undergone a complete conversion of all lens epithelial cells into fiber cells. These data suggest that shortly after lens vesicle closure, β1-integrin blocks inappropriate differentiation of the lens epithelium into fibers, potentially by inhibiting BMP and/or FGF receptor activation. Thus, β1-integrin has an important role in fine-tuning the response of the early lens to the gradient of growth factors that regulate lens fiber cell differentiation. PMID:27596755

An exploration into diffusion tensor imaging in the bovine ocular lens

Directory of Open Access Journals (Sweden)

Ehsan eVaghefi

2013-03-01

Full Text Available We describe our development of the diffusion tensor imaging modality for the bovine ocular lens. Diffusion gradients were added to a spin-echo pulse sequence and the relevant parameters of the sequence were refined to achieve good diffusion weighting in the lens tissue, which demonstrated heterogeneous regions of diffusive signal attenuation. Decay curves for b-value (loosely summarizes the strength of diffusion weighting and TE (determines the amount of MRI-obtained signal were used to estimate apparent diffusion coefficients (ADC and T2 in different lens regions. The ADCs varied by over an order of magnitude and revealed diffusive anisotropy in the lens. Up to 30 diffusion gradient directions, and 8 signal acquisition averages, were applied to lenses in culture in order to improve maps of diffusion tensor eigenvalues, equivalent to ADC, across the lens. From these maps, fractional anisotropy maps were calculated and compared to known spatial distributions of anisotropic molecular fluxes in the lens. This comparison suggested new hypotheses and experiments to quantitatively assess models of circulation in the avascular lens.

Bacterial adhesion forces to Ag-impregnated contact lens cases and transmission to contact lenses.

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Qu, Wenwen; Busscher, Henk J; van der Mei, Henny C; Hooymans, Johanna M M

2013-03-01

To measure adhesion forces of Pseudomonas aeruginosa, Staphylococcus aureus, and Serratia marcescens to a rigid contact lens (CL), standard polypropylene, and Ag-impregnated lens cases using atomic force microscopy and determine bacterial transmission from lens case to CL. Adhesion forces of bacterial strains to Ag-impregnated and polypropylene lens cases and a rigid CL were measured using atomic force microscopy. Adhesion forces were used to calculate Weibull distributions, from which transmission probabilities from lens case to CL were derived. Transmission probabilities were compared with actual transmission of viable bacteria from a lens case to the CL in 0.9% NaCl and in an antimicrobial lens care solution. Bacterial transmission probabilities from polypropylene lens cases based on force analysis coincided well for all strains with actual transmission in 0.9% NaCl. Bacterial adhesion forces on Ag-impregnated lens cases were much smaller than that on polypropylene and CLs, yielding a high probability of transmission. Comparison with actual bacterial transmission indicated bacterial killing due to Ag ions during colony-forming unit transmission from an Ag-impregnated lens case, especially for P. aeruginosa. Transmission of viable bacteria from Ag-impregnated lens cases could be further decreased by use of an antimicrobial lens care solution instead of 0.9% NaCl. Bacterial transmission probabilities are higher from Ag-impregnated lens cases than from polypropylene lens cases because of small adhesion forces, but this is compensated for by enhanced bacterial killing due to Ag impregnation, especially when in combination with an antimicrobial lens care solution. This calls for a balanced combination of antimicrobial lens care solutions and surface properties of a lens case and CL.