WorldWideScience
1

Branched-chain amino acids, mitochondrial biogenesis, and healthspan: an evolutionary perspective  

UK PubMed Central (United Kingdom)

Malnutrition is common among older persons, with important consequences increasing frailty and morbidity and reducing health expectancy. On the contrary, calorie restriction (CR, a low-calorie dietary...Full Text Available

2

The effect of mitochondrial dysfunction on cytosolic nucleotide metabolism  

DEFF Research Database (Denmark)

Several enzymes of the metabolic pathways responsible for metabolism of cytosolic ribonucleotides and deoxyribonucleotides are located in mitochondria. Studies described in this paper suggest dysfunction of the mitochondria to affect these metabolic pathways and limit the available levels of cytosolic ribonucleotides and deoxyribonucleotides, which in turn can result in aberrant RNA and DNA synthesis. Mitochondrial dysfunction has been linked to genomic instability, and it is possible that the limiting effect of mitochondrial dysfunction on the levels of nucleotides and resulting aberrant RNA and DNA synthesis in part can be responsible for this link. This paper summarizes the parts of the metabolic pathways responsible for nucleotide metabolism that can be affected by mitochondrial dysfunction.

2010-01-01

3

cDNA Cloning and mRNA analysis of PGC-1 in epitrochlearis muscle in swimming-exercised rats.  

Science.gov (United States)

Peroxisome proliferator-activated receptor gamma coactivator-1 (PGC-1), a cold-inducible coactivator of nuclear receptors, stimulates mitochondrial biogenesis and respiration in muscle cells. In the present study, we first cloned a rat PGC-1 gene from a brown adipose tissue cDNA library which encodes a predicted 796-amino-acid protein and exhibits respectively 98% and 95% identity with the mouse and human homologues. Next, we examined the effect of swimming exercise training on the level of expression of the PGC-1 gene in rat epitrochlearis (Epi) muscle. PGC-1 mRNA level in Epi muscle in rats that swam 2 h a day for 3 and 7 days increased dramatically by 154% and 163%, respectively, compared to the non-exercised control group. PGC-1 mRNA up-regulation was not observed in an immersion group treated at 35 degrees C during the training program but without swimming exercise. These results demonstrate that expression of the PGC-1 gene in Epi muscle ...

2000-08-01

5

Mitochondrial transmission during mating in Saccharomyces cerevisiae is determined by mitochondrial fusion and fission and the intramitochondrial segregation of mitochondrial DNA.  

UK PubMed Central (United Kingdom)

To gain insight into the process of mitochondrial transmission in yeast, we directly labeled mitochondrial proteins and mitochondrial DNA (mtDNA) and observed their fate after the fusion of two cells....Full Text Available

1997-07-01

6

Biogenesis of the Protein Storage Vacuole Crystalloid  

UK PubMed Central (United Kingdom)

We identify new organelles associated with the vacuolar system in plant cells. These organelles are defined biochemically by their internal content of three integral membrane proteins: a chimeric reporter...Full Text Available

2000-08-21

7

Kes1p shares homology with human oxysterol binding protein and participates in a novel regulatory pathway for yeast Golgi-derived transport vesicle biogenesis.  

UK PubMed Central (United Kingdom)

The yeast phosphatidylinositol transfer protein (Sec14p) is required for biogenesis of Golgi-derived transport vesicles and cell viability, and this essential Sec14p requirement is abrogated by inactivation...Full Text Available

1996-12-02

8

The Importance of Mitochondrial DNA in Aging and Cancer  

UK PubMed Central (United Kingdom)

Mitochondrial dysfunction has been implicated in premature aging, age-related diseases, and tumor initiation and progression. Alterations of the mitochondrial genome accumulate both in aging tissue...Full Text Available

10

Transcriptional coactivator PGC-1? promotes peroxisomal remodeling and biogenesis  

UK PubMed Central (United Kingdom)

Mitochondria and peroxisomes execute some analogous, nonredundant functions including fatty acid oxidation and detoxification of reactive oxygen species, and, in response to select metabolic cues, undergo...Full Text Available

2010-11-23

11

Rhabdomere biogenesis in Drosophila photoreceptors is acutely sensitive to phosphatidic acid levels  

UK PubMed Central (United Kingdom)

Phosphatidic acid (PA) is postulated to have both structural and signaling functions during membrane dynamics in animal cells. In this study, we show that before a critical time period during rhabdomere...Full Text Available

2009-04-06

12

Homology of SMP domains to the TULIP superfamily of lipid-binding proteins provides a structural basis for lipid exchange between ER and mitochondria  

UK PubMed Central (United Kingdom)

Mitochondria must uptake some phospholipids from the endoplasmic reticulum (ER) for the biogenesis of their membranes. They convert one of these lipids, phosphatidylserine, to phosphatidylethanolamine,...Full Text Available

2010-08-15

13

Natural variation in life history and aging phenotypes is associated with mitochondrial DNA deletion frequency in Caenorhabditis briggsae  

UK PubMed Central (United Kingdom)

BackgroundMutations that impair mitochondrial functioning are associated with a variety of metabolic and age-related disorders. A barrier to rigorous tests of the role of mitochondrial...Full Text Available

14

Mitochondrial DNA repair and association with aging - an update  

UK PubMed Central (United Kingdom)

Mitochondrial DNA is constantly exposed to oxidative injury. Due to its location close to the main site of reactive oxygen species, the inner mitochondrial membrane, mtDNA is more susceptible...Full Text Available

2010-08-01

15

Mitochondrial DNA haplogroups in early-onset Alzheimer's disease and frontotemporal lobar degeneration  

UK PubMed Central (United Kingdom)

BackgroundMitochondrial dysfunction, oxidative damage and the accumulation of somatic mutations in mitochondrial DNA (mtDNA) have been associated with certain neurodegenerative disorders....Full Text Available

16

Identification of Potential Calorie Restriction-Mimicking Yeast Mutants with Increased Mitochondrial Respiratory Chain and Nitric Oxide Levels  

UK PubMed Central (United Kingdom)

Calorie restriction (CR) induces a metabolic shift towards mitochondrial respiration; however, molecular mechanisms underlying CR remain unclear. Recent studies suggest that CR-induced mitochondrial...Full Text Available

17

Human mitochondrial transcription factor A reduction and mitochondrial dysfunction in Hashimoto's hypothyroid myopathy.  

UK PubMed Central (United Kingdom)

BACKGROUND: Mitochondrial changes have been described in muscle tissue in acquired hypothyroidism. Among the molecular mechanisms by which thyroid hormones regulate expression of nuclear genes encoding...Full Text Available

2002-06-01

18

The sites and topology of mitochondrial superoxide production  

UK PubMed Central (United Kingdom)

Mitochondrial superoxide production is an important source of reactive oxygen species in cells, and may cause or contribute to ageing and the diseases of ageing. Seven major sites of superoxide...Full Text Available

2010-08-01

19

Mitochondrial uncoupling and lifespan  

UK PubMed Central (United Kingdom)

The quest to understand why we age has given rise to numerous lines of investigation that have gradually converged to include metabolic control by mitochondrial activity as a major player. That...Full Text Available

2010-01-01

20

Mitochondrial ROS production correlates with, but does not directly regulate lifespan in drosophila  

UK PubMed Central (United Kingdom)

The Mitochondrial Free Radical Theory of Aging (MFRTA) is currently one of the most widely accepted theories used to explain aging....Full Text Available

21

Mitochondrial Potassium ATP Channels and Retinal Ischemic Preconditioning  

UK PubMed Central (United Kingdom)

PURPOSETo examine the mechanisms of ischemic preconditioning (IPC) related to the opening of mitochondrial KATP (mKATP) channels in the retina.Full Text Available

2006-05-01

22

Mitochondrial Dysfunction: The Road to Alpha-Synuclein Oligomerization in PD  

UK PubMed Central (United Kingdom)

While the etiology of Parkinson's disease remains largely elusive, there is accumulating evidence suggesting that mitochondrial dysfunction occurs prior to the onset of symptoms in Parkinson's disease....Full Text Available

23

Comparative and phylogenomic studies on the mitochondrial genomes of Pentatomomorpha (Insecta: Hemiptera: Heteroptera)  

UK PubMed Central (United Kingdom)

BackgroundNucleotide sequences and the gene arrangements of mitochondrial genomes are effective tools for resolving phylogenetic problems. Hemipteroid insects are known to possess...Full Text Available

24

A mathematical model of mitochondrial swelling  

UK PubMed Central (United Kingdom)

BackgroundThe permeabilization of mitochondrial membranes is a decisive event in apoptosis or necrosis culminating in cell death. One fundamental mechanism by which...Full Text Available

25

Customized computer models of eyes with intraocular lenses  

Science.gov (United States)

We compared experimental wave aberrations in pseudophakic eyes with aspheric intraocular lenses (IOLs) to simulate aberrations from numerical ray tracing on customized computer eye models using corneal topography, angle ?, ocular biometry, IOL geometry, and IOL tilt and decentration measured on the same eyes. We found high correlations between real and simulated aberrations even for the eye with only the cornea, and these increased on average when the IOL geometry and position were included. Relevant individual aberrations were well predicted by the complete eye model. Corneal spherical aberration and horizontal coma were compensated by the IOL, and in 58.3% of the cases IOL tilt and decentration contributed to compensation of horizontal coma. We conclude that customized computer eye models are a good representation of real eyes with IOLs and allow understanding of the relative ...

2007-03-01

26

The erratic mitochondrial clock: variations of mutation rate, not population size, affect mtDNA diversity across birds and mammals  

UK PubMed Central (United Kingdom)

BackgroundDuring the last ten years, major advances have been made in characterizing and understanding the evolution of mitochondrial DNA, the most popular marker of molecular biodiversity....Full Text Available

27

The complete mitochondrial genome of the stomatopod crustacean Squilla mantis  

UK PubMed Central (United Kingdom)

BackgroundAnimal mitochondrial genomes are physically separate from the much larger nuclear genomes and have proven useful both for phylogenetic studies and for understanding genome...Full Text Available

28

SLC25A4 - solute carrier family 25 (mitochondrial carrier; adenine...  

Science.gov (United States)

The official name of this gene is "solute carrier family 25 (mitochondrial carrier; adenine nucleotide translocator), member 4." SLC25A4 is the gene's official symbol. The...

2011-08-13

29

Regulation of life span by mitochondrial respiration: the HIF-1 and ROS connection  

UK PubMed Central (United Kingdom)

A mild reduction in mitochondrial respiration extends the life span of many species, including C. elegans. We recently showed that hypoxia-inducible factor 1 (HIF-1) is required for...Full Text Available

30

Reduced-Median-Network Analysis of Complete Mitochondrial DNA Coding-Region Sequences for the Major African, Asian, and European Haplogroups  

UK PubMed Central (United Kingdom)

The evolution of the human mitochondrial genome is characterized by the emergence of ethnically distinct lineages or haplogroups. Nine European, seven Asian (including Native American), and three African...Full Text Available

2002-05-01

31

Phylogeny of Mitochondrial DNA Macrohaplogroup N in India, Based on Complete Sequencing: Implications for the Peopling of South Asia  

UK PubMed Central (United Kingdom)

To resolve the phylogeny of the autochthonous mitochondrial DNA (mtDNA) haplogroups of India and determine the relationship between the Indian and western Eurasian mtDNA pools more precisely, a diverse...Full Text Available

2004-12-01

32

Impact of Lifelong Sedentary Behavior on Mitochondrial Function of Mice Skeletal Muscle  

UK PubMed Central (United Kingdom)

This study investigated the impact of lifelong sedentariness on skeletal muscle mass and mitochondrial function. Thirty C57BL/6 strain mice (2 months) were randomly divided into three groups (young-Y;...Full Text Available

2009-09-01

33

A Mitochondrial Superoxide Signal Triggers Increased Longevity in Caenorhabditis elegans  

UK PubMed Central (United Kingdom)

The nuo-6 and isp-1 genes of C. elegans encode, respectively, subunits of complex I and III of the mitochondrial respiratory chain. Partial loss-of-function...Full Text Available

2010-12-01

34

A Conserved Role for Phosphoinositide-3-Kinase but Not Akt Signaling in Mitochondrial Adaptations that Accompany Physiological Cardiac Hypertrophy  

UK PubMed Central (United Kingdom)

Physiological cardiac hypertrophy is associated with mitochondrial adaptations that are characterized by activation of PGC-1α and increased fatty acid oxidative (FAO) capacity. It is...Full Text Available

2007-10-01

35

'Sheltered disruption' of Neurospora crassa MOM22, an essential component of the mitochondrial protein import complex.  

UK PubMed Central (United Kingdom)

MOM22 is a component of the protein import complex of the mitochondrial outer membrane of Neurospora crassa. Using the newly developed procedure of 'sheltered disruption', we created a heterokaryotic...Full Text Available

1995-03-15

36

Regulation of Senescence in Cancer and Aging  

UK PubMed Central (United Kingdom)

Senescence is regarded as a physiological response of cells to stress, including telomere dysfunction, aberrant oncogenic activation, DNA damage, and oxidative stress. This stress response has an antagonistically...Full Text Available

37

Detection of Mitochondrial DNA Mutations in Mammary ...  

Science.gov (United States)

... Loss of Heterozygosity in Normal Breast Epithelial Tissue and Benign Breast Lesions in BRCA1/2 Carriers with Breast Cancer. ...

2004-09-01

38

Determination of the Correlation Between Stallion-s Age and Number of Sex Chromosome Aberrations in Spermatozoa  

British Library Electronic Table of Contents (United Kingdom)

Contents The aim of this study was a cytogenetic analysis of stallions semen to find sex chromosome aberrations and to determine if there was an association between stallion-s age and aberration frequency for the sex chromosomes. Sperm samples were collected from 22 stallions of various age from 3 to 23-years. Multicolour FISH was performed on each sample, using probes for the sex chromosomes and EGFR gene, localized on 4p12 in domestic horse. A total of 26199 sperm cells were analysed (from 1 070 to 1 532 per animal). Among the analysed cells, there were 50.318% with X chromosome, 48.543% with Y chromosome and 1.139% with aberrant chromosomes. The frequency of aberrations was: sex chromosomes nullisomy (0.466%), XY aneuploidy (0.454%), XX disomy (0.146%), YY disomy (0.041%), diploidy (0.0...

2011-01-01

39

T-2 mycotoxin inhibits mitochondrial protein synthesis  

Energy Technology Data Exchange (ETDEWEB)

The authors investigated the effect of T-2 toxin on rat liver mitochondrial protein synthesis. Isolated rat liver mitochondria were supplemented with an S-100 supernatant from rat liver and an external ATP-generating system. An in-vitro assay employing cycloheximide, and inhibitor of cytoplasmic protein synthesis, and chloramphenicol, and inhibitor of mitochondrial protein synthesis, to distinguish mitochondrial protein synthesis from the cytoplasmic process. Amino acid incorporation into mitochondria was dependent on the concentration of mitochondria and was inhibited by chloramphenicol. The rate of uptake of tritium leucine into mitochondrial protein was unaffected by the addition of T-2 toxin and was not a rate-limiting step in incorporation. However, 0.02 micrograms/ml of T-2 toxin decreased the rate of protein synthesis inhibition correlated with the amount of T-2 toxin taken up by the ...

1988-01-01

40

Fabrication and characterization of low aberration micrometer-sized electron lenses  

British Library Electronic Table of Contents (United Kingdom)

Intrinsic spherical aberrations of electron lenses have been the major resolution limiting factor in electron microscopes for several decades. While effective correctors have recently been implemented, an alternative to correct these aberrations is to circumvent them by scaling down lens dimensions by several orders of magnitude. We have fabricated electrostatic lenses exhibiting one micrometer diameter apertures and evaluated their beam forming properties against predictions from numerical ray tracing simulations. It turns out that it is routinely possible to shape a paraxial low-energy electron beam by such micron-sized lenses. Beam profiles have been measured both at a distant detector as well as in a plane close to the lens. It is shown that the lens can form a parallel beam extending ...

2010-01-01

41

Mitochondrial DNA background modulates the assembly kinetics of OXPHOS complexes in a cellular model of mitochondrial disease  

British Library Electronic Table of Contents (United Kingdom)

Lebers hereditary optic neuropathy (LHON), the most frequent mitochondrial disorder, is mostly due to three mitochondrial DNA (mtDNA) mutations in respiratory chain complex I subunit genes: 3460/ND1, 11778/ND4 and 14484/ND6. Despite considerable clinical evidences, a genetic modifying role of the mtDNA haplogroup background in the clinical expression of LHON remains experimentally unproven. We investigated the effect of mtDNA haplogroups on the assembly of oxidative phosphorylation (OXPHOS) complexes in transmitochondrial hybrids (cybrids) harboring the three common LHON mutations. The steady-state levels of respiratory chain complexes appeared normal in mutant cybrids. However, an accumulation of low molecular weight subcomplexes suggested a complex I assembly/stability defect, which was ...

2008-01-01

42

Copper deficiency alters the neurochemical profile of developing rat brain  

UK PubMed Central (United Kingdom)

Copper deficiency is associated with impaired brain development and mitochondrial dysfunction. Perinatal copper deficiency was produced in Holtzman rats. In vivo proton NMR...Full Text Available

2009-06-01

43

A PRELIMINARY PHYLOGENETIC ANALYSIS OF METAPENAEOPSIS (DECAPODA: PENAEIDAE) BASED ON MITOCHONDRIAL DNA SEQUENCES OF ...  

Science.gov (United States)

... each species studied are listed in Table 1. Penaeus monodon Fabricius, 1798 (family Penaeidae) and Solenocera koelbeli De Man, ... ...

44

A Critical Reassessment of the Role of Mitochondria in Tumorigenesis  

UK PubMed Central (United Kingdom)

BackgroundMitochondrial DNA (mtDNA) is being analyzed by an increasing number of laboratories in order to investigate its potential role as an active marker of tumorigenesis...Full Text Available

2005-11-01

45

Ultrasmall spot size scanning laser ophthalmoscopy  

UK PubMed Central (United Kingdom)

An ultrasmall spot size scanning laser ophthalmoscope has been developed that employs an annular aberration-corrected incident beam to increase the effective numerical aperture of the eye thereby reducing...Full Text Available

46

Ubiquitin over-expression phenotypes and ubiquitin gene molecular misreading during aging in Drosophila melanogaster  

UK PubMed Central (United Kingdom)

Molecular Misreading (MM) is the inaccurate conversion of genomic information into aberrant proteins. For example, when RNA polymerase II transcribes a GAGAG motif it synthesizes at low frequency RNA...Full Text Available

47

Synaptic Signaling and Aberrant RNA Splicing in Autism Spectrum Disorders  

UK PubMed Central (United Kingdom)

Interactions between presynaptic and postsynaptic cellular adhesion molecules (CAMs) drive synapse maturation during development. These trans-synaptic interactions are regulated by alternative splicing...Full Text Available

48

Substance Misuse Treatment for High Risk Chronic Pain Patients on Opioid Therapy: A Randomized Trial  

UK PubMed Central (United Kingdom)

Chronic pain patients who show aberrant drug-related behavior often are discontinued from treatment when they are noncompliant with their use of opioids for pain. The purpose of this study was...Full Text Available

2010-09-01

49

Structural aberrations in group A Staphylococcus bacteriophages.  

UK PubMed Central (United Kingdom)

Six related Staphylococcus phages spontaneously produced various abnormal head and tail structures: (i) giant capsids which were tailed and apparently contained nucleic acid; (ii) regular and irregular...Full Text Available

1976-05-01

50

Poland's anomaly. Natural history and long-term results of chest wall reconstruction in 33 patients.  

UK PubMed Central (United Kingdom)

Poland's anomaly is an uncommon congenital aberration of the chest wall characterized by absence of the pectoralis major muscle and other nearby musculoskeletal components. In this series, a wide spectrum...Full Text Available

1988-12-01

51

Number of aberrant crypt foci associated with adiposity and IGF1 bioavailability  

UK PubMed Central (United Kingdom)

BackgroundDysregulation of the insulin-like growth factor (IGF) system, a common consequence of adiposity-induced insulin resistance, may be a key underlying mechanism...Full Text Available

2009-07-01

52

Nonsteroidal Anti-Inflammatory Drugs for Wounds: Pain Relief or Excessive Scar Formation?  

UK PubMed Central (United Kingdom)

The inflammatory process has direct effects on normal and abnormal wound healing. Hypertrophic scar formation is an aberrant form of wound healing and is an indication of an exaggerated function of...Full Text Available

2010-01-01

53

Intrinsic expression of host genes and intronic miRNAs in prostate carcinoma cells  

UK PubMed Central (United Kingdom)

BackgroundRecent data show aberrant and altered expression of regulatory noncoding micro (mi) RNAs in prostate cancer (PCa). A large number of miRNAs are encoded in organized intronic...Full Text Available

54

Genetic Heterogeneity in Severe Congenital Neutropenia: How Many Aberrant Pathways Can Kill a Neutrophil?  

UK PubMed Central (United Kingdom)

Purpose of reviewSevere congenital neutropenia (SCN) is a primary immunodeficiency in which lack of neutrophils causes inadequate innate immune host response to bacterial...Full Text Available

2007-12-01

56

Developmental abnormalities and epimutations associated with DNA hypomethylation mutations.  

UK PubMed Central (United Kingdom)

A number of aberrant morphological phenotypes were noted during propagation of the Arabidopsis thaliana DNA hypomethylation mutant, ddm1, by repeated self-pollination. Onset of a spectrum of morphological...Full Text Available

1996-10-29

57

Chromosome aberrations in human lymphocytes from the plateau region of the Bragg curve for a carbon-ion beam  

Energy Technology Data Exchange (ETDEWEB)

Radiotherapy with high-energy carbon ion beams can be more advantageous compared to photons because of better physical dose distribution and higher biological efficiency in tumour cell sterilization. Despite enhanced normal tissue sparing, damage incurred by normal cells at the beam entrance is unavoidable and may affect the progeny of surviving cells in the form of inheritable cytogenetic alterations. Furthermore, the quality of the beam along the Bragg curve is modified by nuclear fragmentation of projectile and target nuclei in the body. We present an experimental approach based on the use of a polymethylmethacrylate (PMMA) phantom that allows the simultaneous exposure to a particle beam of several biological samples positioned at various depths along the beam path. The device was used to measure the biological effectiveness of a 60 MeV/amu carbon-ion beam at inducing chromosomal aberrations in G{sub 0}-human peripheral blood lymphocytes. Chromosome spreads were ...

2007-06-15

58

An integrative multi-dimensional genetic and epigenetic strategy to identify aberrant genes and pathways in cancer  

UK PubMed Central (United Kingdom)

BackgroundGenomics has substantially changed our approach to cancer research. Gene expression profiling, for example, has been utilized to delineate subtypes of cancer, and facilitated...Full Text Available

59

Aberrant repair and fibrosis development in skeletal muscle  

UK PubMed Central (United Kingdom)

The repair process of damaged tissue involves the coordinated activities of several cell types in response to local and systemic signals. Following acute tissue injury, infiltrating inflammatory cells...Full Text Available

60

A novel role of the aryl hydrocarbon receptor (AhR) in centrosome amplification - implications for chemoprevention  

UK PubMed Central (United Kingdom)

BackgroundCentrosome aberrations can cause genomic instability and correlate with malignant progression in common human malignancies such as breast and prostate cancer. Deregulation...Full Text Available

61

A non-radioactive dot-blot assay for transglutaminase activity  

UK PubMed Central (United Kingdom)

Aberrant transglutaminase (TG) activity has been implicated in the pathology of numerous diseases including Huntington disease and Alzheimer disease. To fully characterize the role of TGs in...Full Text Available

2009-07-01

62

The nanoworld through aberration corrected lenses  

International Nuclear Information System (INIS)

The advent of aberration correction for electron microscope lenses has produced a significant advance in the improvement of resolution in microscopy. This improvement, while significant in itself, promises to have its most profound impact in materials science when it delivers quantitative information to challenge models and modellers. This capability for an electron microscope-modelling synergy to deliver useful results at the atomic level is not yet firmly established. For this reason, one of the major challenges for electron microscopy in materials science over this decade is to study systems where electron microscopists and modellers can work collaboratively. This paper explores some examples.

2010-07-01

63

Smart Acquisition EELS  

Energy Technology Data Exchange (ETDEWEB)

Electron energy loss (EEL) spectroscopy and high angle annular dark field (HAADF) imaging in aberration-corrected electron microscopes are powerful techniques to determine the chemical composition and structure of materials at atomic resolution. We have implemented Smart Acquisition, a flexible system of scanning transmission electron microsocpy (STEM) beam position control and EELS collection, on two aberration-corrected dedicated cold field emission gun (FEG) STEMs located at SuperSTEM, Daresbury Laboratory. This allows the collection of EEL spectra from spatially defined areas with a much lower electron dose possible than existing techniques such as spectrum imaging.

2010-07-01

64

Effects of gamma irradiation on the sperm transmission and oviposition response in Helicoverpa armigera (L. NOCTUIDAE)  

International Nuclear Information System (INIS)

Transmissions of sperm by unirradiated and irradiated cotton bollworm, Helicoverpa armigera, were studied by live dissection of females immediately after the initiation of mating. In cotton bollworm the sperm transfer was rather a complex process. In fact unirradiated males failed to transfer sperm in about 19% of their matings. When irradiated with 250 Gy and 400 Gy, aberrations of sperm transmission were about 21% and 50% respectively. The failure of spermatophore 'cap' location was an important reason of sperm transmission aberrations. When females mated to high-dose-irradiated males, their oviposition response appeared abnormal

2002-02-01

65

Characterization of a novel plasmid-like element in Neurospora crassa derived mostly from the mitochondrial DNA.  

UK PubMed Central (United Kingdom)

We have identified a plasmid-like element within mitochondria of Neurospora crassa strain stp-B1. It is derived from the EcoRI-4 and EcoRI-6 regions of the mitochondrial DNA, and an additional 124 bp...Full Text Available

1990-10-11

66

A unique horizontal gene transfer event has provided the octocoral mitochondrial genome with an active mismatch repair gene that has potential for an unusual self-contained function  

UK PubMed Central (United Kingdom)

BackgroundThe mitochondrial genome of the Octocorallia has several characteristics atypical for metazoans, including a novel gene suggested to function in DNA repair. This mtMutS...Full Text Available

67

The disruption of l-carnitine metabolism by aluminum toxicity and oxidative stress promotes dyslipidemia in human astrocytic and hepatic cells  

British Library Electronic Table of Contents (United Kingdom)

l-Carnitine is a critical metabolite indispensable for the metabolism of lipids as it facilitates fatty acid transport into the mitochondrion where b-oxidation occurs. Human astrocytes (CCF-STTG1 cells) and hepatocytes (HepG2 cells) exposed to aluminum (Al) and hydrogen peroxide (H2O2), were characterized with lower levels of l-carnitine, diminished b-oxidation, and increased lipid accumulation compared to the controls. g-Butyrobetainealdehyde dehydrogenase (BADH) and butyrobetaine dioxygenase (BBDOX), two key enzymes mediating the biogenesis of l-carnitine, were sharply reduced during Al and H2O2 challenge. Exposure of the Al and H2O2-treated cells to a-ketoglutarate (KG), led to the recovery of l-carnitine production with the concomitant reduction in ROS levels. It appears that the chann...

2011-01-01

68

[Molecular analysis of cytoplasmic male sterility]. Progress report, June 1, 1989--June 15, 1991  

Energy Technology Data Exchange (ETDEWEB)

We have determined the actual RNA sequence of four mitochondrial genes: pcf, nad3, rps12, and coxII. Because plant mitochondrial proteins cannot be predicted from DNA sequences, the actual primary structures of the encoded proteins were unknown. We have gained information concerning the process of RNA editing. Editing can occur before splicing. Our data is consistent with the hypothesis that RNA editing is not simultaneous with transcription. Unlike other systems, the process of editing in plant does not exhibit a discernable direction. As a result of our RNA editing studies, we have produced a number of clones of the proper coding regions tube used for incorporating these mitochondrial genes into the nucleus. 6 refs., 4 figs.

1991-12-31

69

Uncoupling action of polychlorinated biphenyls (Kanechlor-400) on oxidative phosphorylation in rat liver mitochondria  

Energy Technology Data Exchange (ETDEWEB)

A study was made of the uncoupling action of polychlorinated biphenyls (Kanechlor-400) on oxidative phosphorylation in rat liver mitochondria. Kanechlor-400 (KC-400) at 20 ..mu..g/ml stimulated state 4 respiration of rat liver mitochondria more than 4-fold with ..cap alpha..-ketoglutarate/malate as a substrate, and released the oligomycin-inhibited state 3 respiration. KC-400 also dissipated the membrane potential across the mitochondrial membranes; thus, it acts as an uncoupler of oxidative phosphorylation in rat liver mitochondria. KC-400 altered the permeability properties of mitochondrial membranes as evidenced by the release of endogenous K/sup +/ and the oxidation of exogenously supplied NADH. It is concluded that KC-400 produces a nonspecific increase in mitochondrial ion permeability, thereby dissipating membrane potential, which leads to the uncoupling.

1984-03-01

70

Mitochondrial NADH:ubiquinone oxidoreductase (complex I) in eukaryotes: A highly conserved subunit composition highlighted by mining of protein databases  

British Library Electronic Table of Contents (United Kingdom)

Complex I (NADH:ubiquinone oxidoreductase) is the largest enzyme of the mitochondrial respiratory chain. Compared to its bacterial counterpart which encompasses 14-17 subunits, mitochondrial complex I has almost tripled its subunit composition during evolution of eukaryotes, by recruitment of so-called accessory subunits, part of them being specific to distinct evolutionary lineages. The increasing availability of numerous broadly sampled eukaryotic genomes now enables the reconstruction of the evolutionary history of this large protein complex. Here, a combination of profile-based sequence comparisons and basic structural properties analyses at the protein level enabled to pinpoint homology relationships between complex I subunits from fungi, mammals or green plants, previously identified...

2011-01-01

71

Isolation of functional mitochondria from rat kidney and skeletal muscle without manual homogenization  

British Library Electronic Table of Contents (United Kingdom)

Isolation of functional and intact mitochondria from solid tissue is crucial for studies that focus on the elucidation of normal mitochondrial physiology and/or mitochondrial dysfunction in conditions such as aging, diabetes, and cancer. There is growing recognition of the importance of mitochondria both as targets for drug development and as off-target mediators of drug side effects. Unfortunately, mitochondrial isolation from tissue is generally carried out using homogenizer-based methods that require extensive operator experience to obtain reproducible high-quality preparations. These methods limit dissemination, impede scale-up, and contribute to difficulties in reproducing experimental results over time and across laboratories. Here we describe semiautomated methods to disrupt tissue ...

2011-01-01

72

A PAC containing the human mitochondrial DNA polymerase gamma gene (POLG) maps to chromosome 15q25  

Energy Technology Data Exchange (ETDEWEB)

The human mitochondrial DNA (mtDNA) is a closed circular, 16,569-bp double-stranded DNA, encoding 13 genes whose protein products are subunits of the oxidative phosphorylation system required for synthesis of most of the ATP consumed by eukaryotic cells. Point mutations of the mtDNA that cause multi-tissue, loss-of-energy syndromes, called mitochondrial encephalomyopathies (e.g., MERRF and MELAS), have been identified. In addition, large-scale deletions of the human mtDNA have been identified and are the molecular bases for the neonatal and adolescent onset loss-of-energy syndromes Pearson and Kearns-Sayer, respectively. 5 refs., 1 fig.

1997-03-01

73

Fabrication and characterization of low aberration micrometer-sized electron lenses.  

Science.gov (United States)

Intrinsic spherical aberrations of electron lenses have been the major resolution limiting factor in electron microscopes for several decades. While effective correctors have recently been implemented, an alternative to correct these aberrations is to circumvent them by scaling down lens dimensions by several orders of magnitude. We have fabricated electrostatic lenses exhibiting one micrometer diameter apertures and evaluated their beam forming properties against predictions from numerical ray tracing simulations. It turns out that it is routinely possible to shape a paraxial low-energy electron beam by such micron-sized lenses. Beam profiles have been measured both at a distant detector as well as in a plane close to the lens. It is shown that the lens can form a parallel beam extending no more than 800 nm from the optical axes at a distance of 200 microm beyond the lens exit. We believe that these findings constitute a prerequisite to derive ...

2010-04-24

74

Triosephosphates Modulate Leaf Mitochondrial Phosphorylation by Inhibition and Uncoupling of Electron Transport 1  

UK PubMed Central (United Kingdom)

The effect of TP (triosephosphates:glyceraldehyde-3 phosphate, GAP, +dihydroxyacetone phosphate, DHAP) on respiration, phosphorylation and matrix ATP/ADP ratios of isolated oat mesophyll mitochondria...Full Text Available

1985-11-01

75

The mitochondrial p53 pathway  

UK PubMed Central (United Kingdom)

p53 is one of the most mutated tumor suppressors in human cancers and as such has been intensively studied for a long time. p53 is a major orchestrator of the cellular response to a broad array...Full Text Available

2009-05-01

76

The inhibition of mitochondrial DNA polymerase gamma from animal cells by intercalating drugs.  

Science.gov (United States)

DNA polymerase gamma from purified nuclei of EMT-6 cells (mice) seems to be identical to the mitochondrial DNA polymerase from the same source following several criteria. These two enzyme activities are strongly inhibited by ethidium bromide and acriflavin, while proflavin, acridine orange, daunomycin and chloroquine inhibition is less pronounced. In the case of DNA polymerases alpha and beta very little inhibition by ethidium bromide was observed. Intercalation of this dye in a poly dA-dT 12-18 template-primer was studied spectrophotometrically under conditions similar to those in the in vitro DNA polymerase assay. The polymerase assay. The inhibition by this drug of the mitochondrial DNA polymerase gamma activity was shown to be competitive at varying concentrations of TTP while the inhibition was of the non-competitive type at different concentrations of poly dA-dT 12-18. We conclude that the drug, most probably in the intercalated form, is ...

1978-06-01

77

The Mitochondrial Isovaleryl-Coenzyme A Dehydrogenase of Arabidopsis Oxidizes Intermediates of Leucine and Valine Catabolism1  

UK PubMed Central (United Kingdom)

We recently identified a cDNA encoding a putative isovaleryl-coenzyme A (CoA) dehydrogenase in Arabidopsis (AtIVD). In animals, this homotetrameric enzyme is located in mitochondria and catalyzes the...Full Text Available

2001-06-01

78

The Cell Non-Autonomous Nature of Electron Transport Chain-Mediated Longevity  

UK PubMed Central (United Kingdom)

SummaryThe life span of C. elegans can be increased via reduced function of the mitochondria; however, the extent to which mitochondrial alteration in a single,...Full Text Available

2011-01-07

79

Stressed-Induced TMEM135 Protein Is Part of a Conserved Genetic Network Involved in Fat Storage and Longevity Regulation in Caenorhabditis elegans  

UK PubMed Central (United Kingdom)

Disorders of mitochondrial fat metabolism lead to sudden death in infants and children. Although survival is possible, the underlying molecular mechanisms which enable this outcome have not yet been...Full Text Available

80

SirT3 suppresses hypoxia inducible factor 1? and tumor growth by inhibiting mitochondrial ROS production  

UK PubMed Central (United Kingdom)

It has become increasing clear that alterations in cellular metabolism have a key role in the generation and maintenance of cancer. Some of the metabolic changes can be attributed to the activation...Full Text Available

2011-06-30

81

Regulation of the brown and white fat gene programs through a PRDM16/CtBP transcriptional complex  

UK PubMed Central (United Kingdom)

Brown fat is a specialized tissue that can dissipate energy and counteract obesity through a pattern of gene expression that greatly increases mitochondrial content and uncoupled respiration. PRDM16...Full Text Available

2008-05-15

82

Reconstructing Mammalian Phylogenies: A Detailed Comparison of the Cytochrome b and Cytochrome Oxidase Subunit I Mitochondrial Genes  

UK PubMed Central (United Kingdom)

The phylogeny and taxonomy of mammalian species were originally based upon shared or derived morphological characteristics. However, genetic analyses have more recently played an increasingly important...Full Text Available

83

Rapid toxicity testing based on mitochondrial respiratory activity  

Energy Technology Data Exchange (ETDEWEB)

The need exists for rapid and inexpensive methods to determine the health effects of environmental contaminants on biological systems. One of the current research approaches for assessing cytotoxicity is to monitor the respiratory activity of the mitochondrion, a sensitive, nonspecific subcellular target site. Detected changes in mitochondrial function after the addition of a test chemical could be correlated to toxic effects. Mitochondrial respiration can be characterized by three indices: state 3 and state 4 respiratory rates, and the respiratory control ratio (RCR). State 4, the idle or resting state, results when coupled mitochondrial respire in a medium containing inorganic phosphate and a Kreb's cycle substrate in the absence of a phosphate acceptor such as adenosine diphosphate (ADP). In the presence of ADP the respiration rate increases to a maximum (state 3), accompanied by phosphorylation of ADP to ...

1990-05-01

84

Phylogenetic inference in Rafflesiales: the influence of rate heterogeneity and horizontal gene transfer  

UK PubMed Central (United Kingdom)

BackgroundThe phylogenetic relationships among the holoparasites of Rafflesiales have remained enigmatic for over a century. Recent molecular phylogenetic studies using the mitochondrial...Full Text Available

85

Opposing function of mitochondrial prohibitin in aging  

UK PubMed Central (United Kingdom)

While specific signalling cascades involved in aging, such as the insulin/IGF-1 pathway, are well-described, the actual metabolic changes they elicit to prolong lifespan remain obscure. Nevertheless,...Full Text Available

86

Molecular studies of the uncoupling protein  

Energy Technology Data Exchange (ETDEWEB)

The uncoupling protein (UCP) is a proton/anion transporter found in the inner mitochondrial membrane of brown adipocyte. Although UCP has nor been detected in mitochondria from any other tissue, it shares structural and catalytic properties with several other mitochondrial carrier proteins. Although UCP was discovered only recently it is one of the most extensively studied mitochondrial carrier proteins.More recently, the mouse, rat, and human genes encoding for UCP have been isolated and sequenced. The availability of these various tools has led to several significant observations. UCP gene expression is strongly controlled at the level of transcription by signals that are activated after the stimulation of brown adipocytes by norepinephrine. The comparison of UCP gene with the genes encoding the adenine nucleotide translocator revealed the existence of structural and evolutionary homologies. Moreover, in humans the UCP ...

1991-06-01

88

Modulation of ASK1 expression during overexpression of Trx and HSP70 in stressed fish liver mitochondria  

UK PubMed Central (United Kingdom)

Mitochondrial heat shock protein 70 (mtHSP70) is found to play a primary role in cellular defense against physiological stress like exposure to environmental contaminants and helpful in the maintenance...Full Text Available

2009-09-01

89

Mitochondrial function and redox control in the aging eye: Role of MsrA and other repair systems in cataract and macular degenerations  

UK PubMed Central (United Kingdom)

Oxidative stress occurs when the level of prooxidants exceeds the level of antioxidants in cells resulting in oxidation of cellular components and consequent loss of cellular function. Oxidative...Full Text Available

2009-02-01

90

Mitochondrial DNA Damage and Animal Longevity: Insights from Comparative Studies  

UK PubMed Central (United Kingdom)

Chemical reactions in living cells are under strict enzyme control and conform to a tightly regulated metabolic program. However, uncontrolled and potentially deleterious endogenous reactions occur,...Full Text Available

91

Increased superoxide in vivo accelerates age-associated muscle atrophy through mitochondrial dysfunction and neuromuscular junction degeneration  

UK PubMed Central (United Kingdom)

Oxidative stress has been implicated in the etiology of age-related muscle loss (sarcopenia). However, the underlying mechanisms by which oxidative stress contributes to sarcopenia have not been thoroughly...Full Text Available

2010-05-01

92

In vivo expression and mitochondrial targeting of yeast apoiso-1-cytochrome c fusion proteins.  

UK PubMed Central (United Kingdom)

To define the import pathway for apoiso-1-cytochrome c in vivo, the coding region for bacterial chloramphenicol acetyltransferase (CAT) or yeast copper metallothionein (CuMT) was fused to the carboxy...Full Text Available

1990-11-01

93

Immune-mediated bile duct injury: The case of primary biliary cirrhosis  

UK PubMed Central (United Kingdom)

Autoimmune cholangitis would be the appropriate name to define the immune-mediated bile duct injury following the breakdown of tolerance to mitochondrial proteins and the appearance of serum autoantibodies...Full Text Available

2010-10-15

94

Heat Stress Enhances the Accumulation of Polyadenylated Mitochondrial Transcripts in Arabidopsis thaliana  

UK PubMed Central (United Kingdom)

BackgroundPolyadenylation of RNA has a decisive influence on RNA stability. Depending on the organisms or subcellular compartment, it either enhances transcript stability or targets...Full Text Available

95

Genetic Variation at the Mitochondrial DNA 9-bp Repeat Locus in the Sakha of Siberia  

Science.gov (United States)

... 16223, 16292, and 16295, which classify them as haplogroup W (Richards et al. 2000). The sample that was ... belonged to haplogroup B, 2 individuals belonged to haplogroup W, and 1 individual belonged to ...

96

Evidence for Sub-Haplogroup H5 of Mitochondrial DNA as a Risk Factor for Late Onset Alzheimer's Disease  

UK PubMed Central (United Kingdom)

BackgroundAlzheimer's Disease (AD) is the most common neurodegenerative disease and the leading cause of dementia among senile subjects. It has been proposed that AD can be caused...Full Text Available

97

Complete characterization of the edited transcriptome of the mitochondrion of Physarum polycephalum using deep sequencing of RNA  

UK PubMed Central (United Kingdom)

RNAs transcribed from the mitochondrial genome of Physarum polycephalum are heavily edited. The most prevalent editing event is the insertion of single Cs, with Us and dinucleotides...Full Text Available

2011-08-01

98

Common mitochondrial polymorphisms as risk factor for endometrial cancer  

UK PubMed Central (United Kingdom)

Endometrial carcinoma is the most commonly diagnosed gynaecological cancer in developed countries. Although the molecular genetics of this disease has been in the focus of many research laboratories...Full Text Available

99

Characterization of the binding sites for dicarboxylic acids on bovine serum albumin.  

UK PubMed Central (United Kingdom)

Dicarboxylic acids are prominent features of several diseases, including Reye's syndrome and inborn errors of mitochondrial and peroxisomal fatty acid oxidation. Moreover, dicarboxylic acids are potentially...Full Text Available

1991-06-15

100

Cell proliferation depends on mitochondrial Ca2+ uptake: inhibition by salicylate  

UK PubMed Central (United Kingdom)

Store-operated Ca2+ entry (SOCE) is a ubiquitous Ca2+ influx pathway involved in control of multiple cellular and physiological processes including cell proliferation. Recent evidence...Full Text Available

2006-02-15

101

Bistability of Mitochondrial Respiration Underlies Paradoxical Reactive Oxygen Species Generation Induced by Anoxia  

UK PubMed Central (United Kingdom)

Increased production of reactive oxygen species (ROS) in mitochondria underlies major systemic diseases, and this clinical problem stimulates a great scientific interest in the mechanism of ROS generation....Full Text Available

2009-12-01

102

Antianxiety and antidepressant-like effects of AC-5216, a novel mitochondrial benzodiazepine receptor ligand  

UK PubMed Central (United Kingdom)

We investigated the ability of N-benzyl-N-ethyl-2-(7,8-dihydro-7-methyl-8-oxo-2-phenyl-9H-purin-9-yl)acetamide...Full Text Available

2004-08-01

103

Analysis of European mtDNAs for Recombination  

UK PubMed Central (United Kingdom)

The standard paradigm postulates that the human mitochondrial genome (mtDNA) is strictly maternally inherited and that, consequently, mtDNA lineages are clonal. As a result of mtDNA clonality, phylogenetic...Full Text Available

2001-01-01

104

ATG12 Conjugation to ATG3 Regulates Mitochondrial Homeostasis and Cell Death  

UK PubMed Central (United Kingdom)

SUMMARYATG12, an ubiquitin-like modifier required for macroautophagy, has a single known conjugation target, another autophagy regulator called ATG5. Here, we identify ATG3 as...Full Text Available

2010-08-20

105

A new perspective on phylogeny and evolution of tetraodontiform fishes (Pisces: Acanthopterygii) based on whole mitochondrial genome sequences: Basal ecological diversification?  

UK PubMed Central (United Kingdom)

BackgroundThe order Tetraodontiformes consists of approximately 429 species of fishes in nine families. Members of the order exhibit striking morphological diversity and radiated...Full Text Available

106

Towards atomic scale engineering of rare-earth-doped SiAlON ceramics through aberration-corrected scanning transmission electron microscopy  

British Library Electronic Table of Contents (United Kingdom)

Direct visualization of rare earths in @a- and @b-SiAlON unit-cells is performed through Z-contrast imaging technique in an aberration-corrected scanning transmission electron microscope. The preferential occupation of Yb and Ce atoms in different interstitial locations of @b-SiAlON lattice is demonstrated, yielding higher solubility for Yb than Ce. The triangular-like host sites in @a-SiAlON unit cell accommodate more Ce atoms than hexagonal sites in @b-SiAlON. We think that our results will be applicable as guidelines for many kinds of rare-earth-doped materials.

2011-01-01

107

International Lens Design Conference, Monterey, CA, June 11-14, 1990, Proceedings  

Energy Technology Data Exchange (ETDEWEB)

The present conference on lens design encompasses physical and geometrical optics, diffractive optics, the optimization of optical design, software packages, ray tracing, the use of artificial intelligence, the achromatization of materials, zoom optics, microoptics and GRIN lenses, and IR lens design. Specific issues addressed include diffraction-performance calculations in lens design, the optimization of the optical transfer function, a rank-down method for automatic lens design, applications of quadric surfaces, the correction of aberrations by using HOEs in UV and visible imaging systems, and an all-refractive telescope for intersatellite communications. Also addressed are automation techniques for optics manufacturing, all-reflective phased-array imaging telescopes, the thermal aberration analysis of a Nd:YAG laser, the analysis of illumination systems, athermalized FLIR optics, and the design of array systems using shared symmetry.

1990-01-01

108

Contrast Sensitivity and Optical Quality of the Eye after Instillation of Timolol Maleate Gel-Forming Solution and Brinzolamide Ophthalmic Suspension  

British Library Electronic Table of Contents (United Kingdom)

Purpose To investigate the influence of timolol maleate 0.5% gel-forming solution and brinzolamide 1% ophthalmic suspension on contrast sensitivity, ocular higher-order aberration (HOA), and corneal surface light scattering. Design Prospective, comparative study. Participants Forty normal volunteers were enrolled in this study. Methods We evaluated contrast sensitivity, ocular HOA, and corneal light scattering before and 2, 5, 10, and 15 minutes after instillation of antiglaucoma eyedrops. Contrast sensitivity function was assessed with the CSV-1000RN chart (Vector Vision Co., Greenville, OH). Higher-order aberration was measured for a 4-mm pupil using the Hartmann-Shack aberrometer (KR-9000PW; Topcon, Tokyo, Japan). Corneal surface light scattering was quantitatively evaluated by using th...

2010-01-01

109

Mitochondrial DNA variants in Drosophila melanogaster are expressed at the level of the organismal phenotype.  

Science.gov (United States)

A plethora of experimental studies use mtDNA as a marker of demographic processes without questioning the possibility that selection may bias their interpretations. We studied four lines of Drosophila melanogaster that have a standardized nuclear DNA but variable mtDNA. We completed the sequencing of the mitochondrial genomes (excluding the A+T rich region) and compiled the differences. We then assayed male influence on oviposition, starvation resistance, lipid proportion and physical activity. We discuss these results in terms of the known differences between the lines and conclude that naturally occurring mtDNA variants in D. melanogaster are expressed at the level of the organismal phenotype. PMID:21757031

2011-07-05

110

Contribution of the ion-energy distribution to the current-density distribution of a focused-ion beam  

Energy Technology Data Exchange (ETDEWEB)

A general expression for the current-density distribution of a focused-ion beam (FIB) in the chromatic-aberration region is set up in the form of a definite integral. With the experimentally obtained ion-energy distribution of a liquid-metal ion source, its contribution to the FIB current-density distribution is estimated. Calculated results explain the wide-exponential tail of a FIB.

1987-09-01

111

Contribution of the ion-energy distribution to the current-density distribution of a focused-ion beam  

International Nuclear Information System (INIS)

A general expression for the current-density distribution of a focused-ion beam (FIB) in the chromatic-aberration region is set up in the form of a definite integral. With the experimentally obtained ion-energy distribution of a liquid-metal ion source, its contribution to the FIB current-density distribution is estimated. Calculated results explain the wide-exponential tail of a FIB.

112

Amplified B Lymphocyte CD40 Signaling Drives Regulatory B10 Cell Expansion in Mice  

UK PubMed Central (United Kingdom)

BackgroundAberrant CD40 ligand (CD154) expression occurs on both T cells and B cells in human lupus patients, which is suggested to enhance B cell CD40 signaling and play a role...Full Text Available

113

The complete mitochondrial genome of Atelura formicaria (Hexapoda: Zygentoma) and the phylogenetic relationships of basal insects.  

Science.gov (United States)

In this study, the complete sequence of the mitochondrial DNA (mtDNA) of Atelura formicaria (Hexapoda: Zygentoma) is described. The molecule is 15.205 bp in length and it is the third complete mt genome sequenced from the Zygentoma. The genome organization conforms with the putative ancestral insect gene arrangement. All protein coding genes use standard initiation codons (methionine and isoleucine). The exception is nad4 that starts with GTG, a codon used for this purpose in other insect species. A peculiar strand skew bias is observed, given that the PCGs encoded on the J-strand contain more thymines than adenines and more cytosines than guanines. This trend in nucleotide composition has been observed also in the "firebrat" Thermobia domestica (Zygentoma, Lepismatidae), but differs from that of the majority of hexapod species, including Tricholepidion gertschi (Zygentoma, Lepidotrichidae), where adenines and cytosines outnumber thymines and guanines. The presence ...

2009-03-11

114

Mitochondrial genetic damage induced in yeast by a photoactivated furocoumarin in combination with ethidium bromide or ultraviolet light  

International Nuclear Information System (INIS)

Ethidium bromide (EB) and ultraviolet light (UV) in combination are known to produce a synergistic induction of 'petite' mutants in yeast. Two other agents were combined with EB, 3-Carbethoxypsoralene (3 CPs) activated by 365 nm light or #gamma# rays. EB in combination with 3 CPs also resulted in an enhanced production of 'petite' mutants. After the photoaddition of 3 CPs in exponential phase cells, recovery of the 'petite' mutation during dark liquid holding was inhibited by the presence of EB producing an enhanced number of 'petite' mutants. The behavior of mitochondrial antibiotic resistance markers after individual and combined treatments with EB and 3 CPs indicates a random loss of markers after EB and a preferential loss of a certain region for the 3 CPs photoaddition. The combination of the two agents leads to an additivity of total drug marker losses rather than a synergistic loss. The combination of EB with #gamma# rays produced no enhancement in 'petite' ...

115

Strikingly different penetrance of LHON in two Chinese families with primary mutation G11778A is independent of mtDNA haplogroup background and secondary mutation G13708A  

British Library Electronic Table of Contents (United Kingdom)

The penetrance of Lebers hereditary optic neuropathy (LHON) in families with primary mitochondrial DNA (mtDNA) mutations is very complex. Matrilineal and nuclear genetic background, as well as environmental factors, have been reported to be involved in different affected pedigrees. Here we describe two large Chinese families that show a striking difference in the penetrance of LHON, in which 53.3% and 15.0% of members were affected (Pin vivo mitochondrial oxidative metabolism as described in a previous study. Evolutionary analysis failed to indicate any putatively pathogenic mutation that cosegregated with G11778A in these two pedigrees. Our results suggest that the variable penetrance of LHON in the two Chinese families is independent of both their mtDNA haplotype background and a seconda...

2008-01-01

116

Species in the genus Turritopsis (Cnidaria, Hydrozoa): a molecular evaluation:  

British Library Electronic Table of Contents (United Kingdom)

Abstract Mitochondrial ribosomal gene sequences were used to investigate the status of several populations of hydromedusae belonging to the genus Turritopsis (family Oceaniidae). Several nominal species have been described for this genus, but most of them had been synonymized and attributed to one cosmopolitan species, Turritopsis nutricula. A recent revision based on morphological and reproductive characters, however, has shown that many different populations can be distinguished and that several of the nominal Turritopsis species are likely valid biological species. Our investigation using molecular sequence data of 16S mitochondrial gene confirms these results. The Mediterranean Turritopsis must be attributed to Turritopsis dohrnii and the Turritopsis of New Zealand must be referred to ...

2007-01-01

117

Role of death receptor, mitochondrial and endoplasmic reticulum pathways in different stages of degenerative human lumbar disc  

British Library Electronic Table of Contents (United Kingdom)

Intervertebral disc (IVD) cell apoptosis has been suggested to play an important role in promoting the degeneration process. It has been demonstrated that IVD cell apoptosis occurs through either death receptor, mitochondrial or endoplasmic reticulum (ER) pathway. Our study aimed to explore the relationship among these three pathways and grade of IVD degeneration (IVDD). IVDs were collected from patients with lumbar fracture, vertebral tumor, disc herniation or spondylolisthesis. IVDs were distinguished by MRI and histomorphological examination, cell apoptosis was detected by TUNEL staining. Biomarkers of these three apoptosis pathways were detected by RT-PCR and Western blot. Furthermore, the correlation between apoptosis pathways biomarkers and disc pathology were analyzed. Nucleus pulpo...

2011-01-01

118

Molecular analysis of polymerase gamma gene and mitochondrial polymorphism in fertile and subfertile men  

British Library Electronic Table of Contents (United Kingdom)

Summary CAG trinucleotide repeat length in the nuclear polymerase gamma gene (POLg) has been shown to be associated with men with reduced fertility. The present study investigated the frequency of CAG repeat length genotypes and three exonuclease motifs of the POLg in relation to the frequency of mitochondrial nucleotide substitutions. DNA from semen samples of 93 normozoospermic men and 192 non-normozoospermic men was isolated and the specific regions of the genes were amplified by polymerase chain reactions (PCR) and sequenced to identify mutations. The genotypic frequencies of pooled POLg CAG repeat lengths, =10/!=10 heterozygotes and !=10/!=10 homozygotes, were significantly different between normozoospermic and non-normozoospermic men (p p POLg genotype. Of the 17 men with non-synonym...

2006-01-01

119

Impaired mitochondrial energy metabolism and kinetic properties of cytochrome oxidase following acute aluminium phosphide exposure in rat liver  

British Library Electronic Table of Contents (United Kingdom)

The present study was designed with an aim to analyze the effect of acute aluminium phosphide (ALP) exposure (10mg/kg b.wt, intragastrically) on the kinetic characteristics of cytochrome oxidase and energy metabolism in male Wistar rat liver mitochondria. Liver mitochondrial preparations from ALP-treated rats exhibited significant decrease (66%) in the activity of cytochrome oxidase suggesting that there was a decrease in the catalytic efficiency of the active oxidase molecules on ALP treatment. The decreased activity of cytochrome oxidase with altered NADH and succinic dehydrogenase activities might have contributed towards a significant decline in state 3 and state 4 respiration as observed. These alterations in the electron transport chain complexes in turn adversely affected the ATP sy...

2010-01-01

120

Distributions of spontaneous chromosomal aberrations and of spontaneous and induced SCE and micronuclei in peripheral lymphocytes from a human population  

Energy Technology Data Exchange (ETDEWEB)

Biomonitoring of human populations for exposure to genotoxic/clastogenic agents in the environment or the workplace must depend upon statistical tests for elevations in the frequencies of the biological endpoints being monitored, usually chromosomal aberrations (CA), micronuclei (MN), or sister chromatid exchanges (SCE) in peripheral blood lymphocytes. Statistical tests are based, in turn, upon certain assumptions regarding the distribution of the test statistic. When they are often not recognized as such, tests of significance can be in error, and any conclusion drawn that there is or is not a statistically significant difference between one population sample and another maybe erroneous. In population monitoring this means either false negatives or false positives can result and it is hard to know which is worse. Furthermore, even the intelligent design of studies whose object is to test for an elevated level in an exposed population must depend upon prior ...

1992-12-31

121

Chromosomal study in lymphocytes from subjects living or working in buildings constructed with radioactively contaminated rebar  

Energy Technology Data Exchange (ETDEWEB)

It has recently been found that many buildings in Taiwan were constructed with radioactively contaminated rebar, which raised great concern among the residents as well as governmental officials. In order to investigate the possible cytogenetic damage to the residents of contaminated buildings, a G-banding method was carried out on the lymphocytes of 30 radiation-exposed individuals from four families and one office building, as well as 15 control individuals from laboratory personnel. The estimated cumulative radiation doses for the exposed people range from 19.63 to 280.50 mSv. Altogether, 13 females and 17 males belonging to the radiation-exposed group, and 7 females and 8 males in the control group, were included in this study. With the exception of one sample, at least 500 metaphase spreads were scored and analyzed for each individual. All the recognizable structural aberrations of chromosomes or chromatids were recorded and statistically analyzed. Comparison ...

1997-07-03

122

Chromosomal study in lymphocytes from subjects living or working in buildings constructed with radioactively contaminated rebar  

International Nuclear Information System (INIS)

It has recently been found that many buildings in Taiwan were constructed with radioactively contaminated rebar, which raised great concern among the residents as well as governmental officials. In order to investigate the possible cytogenetic damage to the residents of contaminated buildings, a G-banding method was carried out on the lymphocytes of 30 radiation-exposed individuals from four families and one office building, as well as 15 control individuals from laboratory personnel. The estimated cumulative radiation doses for the exposed people range from 19.63 to 280.50 mSv. Altogether, 13 females and 17 males belonging to the radiation-exposed group, and 7 females and 8 males in the control group, were included in this study. With the exception of one sample, at least 500 metaphase spreads were scored and analyzed for each individual. All the recognizable structural aberrations of chromosomes or chromatids were recorded and statistically analyzed. Comparison ...

123

Updates on Attention-Deficit/Hyperactivity Disorder and Learning Disorders  

British Library Electronic Table of Contents (United Kingdom)

The relationship of attention-deficit/hyperactivity disorder (ADHD) to learning disorders was reviewed and included reading disability, mathematics learning disability, and nonverbal learning disability. Genetic, neuroimaging, and neuropsychological functioning were examined for each disorder, along with a discussion of any existing literature when ADHD co-occurred with the disorder. All the disorders were found to frequently co-occur with ADHD. A review of the underlying neuroanatomic and neurofunctional data found specific structures that frequently co-occur in these disorders with others that are specific to the individual diagnosis. Aberrations in structure and/or function were found for the caudate, corpus callosum, and cerebellum, making these structures sensitive for the disorder bu...

2011-01-01

124

The use of Radioactive labeling in hemoglobin identification  

International Nuclear Information System (INIS)

The basic approach to radioactive labeling techniques in hemoglobin identification consists of mixing 14C labeled normal carrier globin with 3H labeled unknown globin and carrying out the subsequent separations and purifications looking at the distribution of 3H and 14C radioactivity. This technique was devised to ascertain the amino acid substitution in Hb Indianapolis and was instrumental in solving the structure of Hb Vicksburg. It was also useful in determining the purity of gamma-chains from cultures of human and baboon erythroid progenitors. Another use of this technique would be in identifying aberrant peaks of radioactivity in chain separation chromatograms, such as ''pre-peaks''.

125

The early days of parathyroid surgery.  

Science.gov (United States)

The parathyroid endocrine glands, usually four in number and about the size of a split pea, lie on either side of the posterior aspect of the thyroid gland. Occasionally one or more of these structures are found in an aberrant position in the neck or even in the superior mediastinum. The parathyroid secretion, parathormone, regulates the level of serum calcium within sharply defined limits. Lack of parathormone, with lowering of the serum calcium, results in hyper-irritability of skeletal muscle, the clinical condition known as tetany. This is encountered following inadvertent removal or bruising of the parathyroid glands at thyroidectomy. PMID:21488463

2011-03-01

126

Laser ray-tracing method for optical testing.  

Science.gov (United States)

We have developed a novel laser ray-tracing method to measure aberrations in optical systems. It consists of delivering narrow laser pencils (by a laser scanner), recording the spots that are formed on the image plane (with a CCD camera), and computing the position of each centroid. This approach could be considered an experimental (approximate) implementation of standard numerical ray tracing. Several tests and experiments, including a direct comparison with a Hartmann-Shack wave-front sensor, provided highly satisfactory results that confirmed the validity of the method and revealed potential advantages. PMID:18073906

1999-07-15

127

A numerical study of expected accuracy and precision in Calibration-Free Laser-Induced Breakdown Spectroscopy in the assumption of ideal analytical plasma  

Energy Technology Data Exchange (ETDEWEB)

Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS) has been proposed several years ago as an approach for quantitative analysis of Laser-Induced Breakdown Spectroscopy spectra. Recently developed refinement of the spectral processing method is described in the present work. Accurate quantitative results have been demonstrated for several metallic alloys. However, the degree of accuracy that can be achieved with Calibration-Free Laser-Induced Breakdown Spectroscopy analysis of generic samples still needs to be thoroughly investigated. The authors have undertaken a systematic study of errors and biasing factors affecting the calculation in the Calibration-Free Laser-Induced Breakdown Spectroscopy spectra processing. These factors may be classified in three main groups: 1) experimental aberrations (intensity fluctuations and inaccuracy in the correction for spectral efficiency of a detection system), 2) inaccuracy in theoretical parameters used for ...

2007-12-15

128

A numerical study of expected accuracy and precision in Calibration-Free Laser-Induced Breakdown Spectroscopy in the assumption of ideal analytical plasma  

International Nuclear Information System (INIS)

Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS) has been proposed several years ago as an approach for quantitative analysis of Laser-Induced Breakdown Spectroscopy spectra. Recently developed refinement of the spectral processing method is described in the present work. Accurate quantitative results have been demonstrated for several metallic alloys. However, the degree of accuracy that can be achieved with Calibration-Free Laser-Induced Breakdown Spectroscopy analysis of generic samples still needs to be thoroughly investigated. The authors have undertaken a systematic study of errors and biasing factors affecting the calculation in the Calibration-Free Laser-Induced Breakdown Spectroscopy spectra processing. These factors may be classified in three main groups: 1) experimental aberrations (intensity fluctuations and inaccuracy in the correction for spectral efficiency of a detection system), 2) inaccuracy in theoretical parameters used for ...

2007-12-01

129

The effects of diphenyleneiodonium on mitochondrial reactions. Relation of binding of diphenylene[125I]iodonium to mitochondria to the extent of inhibition of oxygen uptake.  

UK PubMed Central (United Kingdom)

1. Several ring-substituted derivatives of diphenyleneiodonium catalyse the exchange of Cl- and OH- ions across the inner membrane of rat liver mitochondria. They also inhibit state 3 and state 3u oxidations...Full Text Available

1976-08-15

130

The dynamin-related GTPase Opa1 is required for glucose-stimulated ATP production in pancreatic beta cells  

UK PubMed Central (United Kingdom)

Previous studies using in vitro cell culture systems have shown the role of the dynamin-related GTPase Opa1 in apoptosis prevention and mitochondrial DNA (mtDNA) maintenance. However, it remains to...Full Text Available

2011-07-01

131

Nuclear receptor co-repressor SMRT regulates mitochondrial oxidative metabolism and mediates aging related metabolic deterioration  

UK PubMed Central (United Kingdom)

SummaryThe transcriptional co-repressor SMRT utilizes two major receptor interacting domains (RID1 and RID2) to mediate nuclear receptor (NR) signaling through epigenetic modification....Full Text Available

2010-12-01

132

Modification of the photodynamic action of delta-aminolaevulinic acid (ALA) on rat pancreatoma cells by mitochondrial benzodiazepine receptor ligands.  

UK PubMed Central (United Kingdom)

We have shown that addition of exogenous delta-aminolaevulinic acid (ALA) to rat pancreatoma AR4-2J cells in culture leads to the increased production of porphobilinogen (PBG) and the accumulation of...Full Text Available

1995-02-01

133

Long-Term Exposure to Ambient Fine Particulate Pollution Induces Insulin Resistance and Mitochondrial Alteration in Adipose Tissue.  

Science.gov (United States)

Objectives: We have previously shown that chronic exposure to ambient fine particulate matter (less than 2.5 ?m in aerodynamic diameter, PM(2.5)) pollution in conjunction with high-fat diet induces insulin resistance through alterations in inflammatory pathways. In this study we evaluated the effects of PM(2.5) exposure over a substantive duration of a rodent's lifespan and focused on the impact of long-term exposure on adipose structure and function.Methods and Results: C57BL/6 mice were exposed to PM(2.5) or filtered air (FA) (6 hours/day, 5 days/week) for duration of 10 months in Columbus, OH. At the end of the exposure, PM(2.5)-exposed mice demonstrated insulin resistance (IR) and a decrease in glucose tolerance compared with the FA-exposed group. Although there were no significant differences in circulating cytokines between PM(2.5)- and FA-exposed groups, circulating adiponectin and leptin were significantly decreased in PM(2.5)-exposed group. PM(2.5) exposure also led to ...

2011-08-27

134

Dietary effects on body composition, glucose metabolism, and longevity are modulated by skeletal muscle mitochondrial uncoupling in mice  

UK PubMed Central (United Kingdom)

Little is known about how diet and energy metabolism interact in determination of lifespan under ad libitum feeding. From 12 weeks of age until death, male and female wild-type (WT) and transgenic (TG)...Full Text Available

2011-02-01

135

Conformational Changes in BAK, a Pore-forming Proapoptotic Bcl-2 Family Member, upon Membrane Insertion and Direct Evidence for the Existence of BH3-BH3 Contact Interface in BAK Homo-oligomers*  

UK PubMed Central (United Kingdom)

During apoptosis, the pro-apoptotic Bcl-2 family proteins BAK and BAX form large oligomeric pores in the mitochondrial outer membrane. Apoptotic factors, including cytochrome c, are...Full Text Available

2010-09-10

136

A novel chenodeoxycholic derivative HS-1200 induces apoptosis in human HT-29 colon cancer cells  

International Nuclear Information System (INIS)

To investigate the growth inhibitory effects, and the underlying mechanism of human colon cancer cell (HT-29) death, induced by a new synthetic bile derivative (HS-1200). Human colon cancer cells (HT-29), in exponential growth phase, were treated with various concentrations of a new synthetic bile acid derivative (HS-1200). The growth inhibitory effects on HT-19 cells were examined using a trypan blue exclusion assay. The extent of apoptosis was determined using agarose gel electrophoresis, TUNEL assays and Hoechst staining. The apoptotic cell death was also confirmed by Western blotting of PARP, caspase-3 and DNA fragmentation factor (DFF) analysis. To investigate the involvement of mitochondria, we employed immunofluorescent staining of cytochrome c and mitochondrial membrane potential analyses. The dose required for the half maximal inhibition (IC_5_0) of the HT-29 cell growth was 100 #approx# 150 #mu# M of HS-1200. Several changes, associated with the apoptosis ...

2002-12-01

137

The ATG1/ATG13 Protein Kinase Complex Is Both a Regulator and a Target of Autophagic Recycling in Arabidopsis.  

Science.gov (United States)

Autophagy is an intracellular recycling route in eukaryotes whereby organelles and cytoplasm are sequestered in vesicles, which are subsequently delivered to the vacuole for breakdown. The process is induced by various nutrient-responsive signaling cascades converging on the Autophagy-Related1 (ATG1)/ATG13 kinase complex. Here, we describe the ATG1/13 complex in Arabidopsis thaliana and show that it is both a regulator and a target of autophagy. Plants missing ATG13 are hypersensitive to nutrient limitations and senesce prematurely similar to mutants lacking other components of the ATG system. Synthesis of the ATG12-ATG5 and ATG8-phosphatidylethanolamine adducts, which are essential for autophagy, still occurs in ATG13-deficient plants, but the biogenesis of ATG8-decorated autophagic bodies does not, indicating that the complex regulates downstream events required for autophagosome enclosure and/or vacuolar delivery. Surprisingly, levels of the ATG1a and ATG13a ...

2011-10-01

138

The mitochondrial genome of the entomophagous endoparasite Xenosvesparum (Insecta: Strepsiptera)  

Energy Technology Data Exchange (ETDEWEB)

In this study, the nearly complete sequence (14,519 bp) of the mitochondrial DNA (mtDNA) of the entomophagous endoparasite Xenos vesparum (Insecta: Strepsiptera) is described. All protein coding genes (PCGs) are in the arrangement known to be ancestral for insects, but three tRNA genes (trnA, trnS(gcu), and trnL(uag)) have transposed to derived positions and there are three tandem copies of trnH, each of which is potentially functional. All of these rearrangements except for that of trnL(uag) is within the short span between nad3 and nad4 and there are numerous blocks of unassignable sequence in this region, perhaps as remnants of larger scale predisposing rearrangements. X. vesparum mtDNA nucleotide composition is strongly biased toward As and Ts, as is typical for insect mtDNAs. There is also significant strand skew in the distribution of these nucleotides, with the J-strand being richer in A than T and in C than G, and the N-strand showing an opposite skew for ...

2005-12-01

139

Assessment of the role of oxygen and mitochondria in heat shock induction of radiation and thermal resistance in Saccharomyces cerevisiae  

Energy Technology Data Exchange (ETDEWEB)

In response to a heat shock, the yeast Saccharomyces cerevisiae undergoes a large increase in its resistance to heat and, by the induction of its recombinational DNA repair capacity, a corresponding increase in resistance to radiation. Yeast which lack mitochondrial DNA, mitochondria-controlled protein synthetic apparatus, aerobic respiration, and electron transport (rho/sup 0/ strain) were used to assess the role of O/sub 2/, mitochondria, and oxidative processes controlled by mitochondria in the induction of these resistances. We have found that rho/sup 0/ yeast grown and heat shocked in either the presence or absence of O/sub 2/ are capable of developing both radiation and heat resistance. We conclude that neither the stress signal nor its cellular consequences of induced heat and radiation resistance are directly dependent on O/sub 2/, mitochondrial DNA, or mitochondria-controlled protein synthetic or oxidative processes.

1983-10-01

140

The morphology and systematics of Mammalodon colliveri (Cetacea: Mysticeti), a toothed mysticete from the Oligocene of Australia  

British Library Electronic Table of Contents (United Kingdom)

Mammalodon colliveri is an unusual toothed archaic mysticete (Cetacea) from the Upper Oligocene Jan Juc Formation of south-east Australia. The morphology of the holotype skull and postcrania are described in detail. Superimposed on the generally plesiomorphic archaeocete-like morphology of Mammalodon are subtle mysticete synapomorphies. Derived features of Mammalodon include a short and bluntly rounded rostrum, reduced premaxillae, and anterodorsally directed orbits. Within Mysticeti, this suite of features is unique. The aberrant rostral morphology of Mammalodon suggests specialization for suction feeding. Janjucetus hunderi is placed in an expanded family Mammalodontidae. Phylogenetic analysis corroborates the monophyly of Basilosauridae, Neoceti, Odontoceti, and Mysticeti, and yields a ...

2010-01-01

141

Spectrograph for free-electron laser experiments  

International Nuclear Information System (INIS)

The design and construction of a Browne-Buechner type round pole face magnetic electron spectrograph is described. The design is based on the first order transfer properties of the bending magnet including the focal surface, dispersion, magnification and resolution. Second order aberrations are compared wit numerical ray tracing results using measured field data to simulate the magnet. The numerical results are also compared with floating wire measurements on the system. Agreement is within one part in 10"4. Data extraction from the instrument is done with an array of copper detectors placed along the focal surface. The spectrograph has been successfully employed in free-electron laser (FEL) experiments for over a year.

1983-03-21

142

Research update: Alpha7 nicotinic acetylcholine receptor mechanisms in Alzheimer's disease  

British Library Electronic Table of Contents (United Kingdom)

Aberrant amyloid-b peptide (Ab) accumulation along with altered expression and function of nicotinic acetylcholine receptors (nAChRs) stand prominently in the etiology of Alzheimer's disease (AD). Since the discovery that Ab is bound to a7 nAChRs under many experimental settings, including post-mortem AD brain, much effort has been expended to understand the implications of this interaction in the disease milieu. This research update will review the current literature on the a7 nAChR-Ab interaction in vitro and in vivo, the functional consequences of this interaction from sub-cellular to cognitive levels, and discuss the implications these relationships might have for AD therapies.

2011-01-01

143

Reactions of the inner surface of carbon nanotubes and nanoprotrusion processes imaged at the atomic scale  

British Library Electronic Table of Contents (United Kingdom)

Although the outer surface of single-walled carbon nanotubes (atomically thin cylinders of carbon) can be involved in a wide range of chemical reactions, it is generally thought that the interior surface of nanotubes is unreactive. In this study, we show that in the presence of catalytically active atoms of rhenium inserted into nanotubes, the nanotube sidewall can be engaged in chemical reactions from the inside. Aberration-corrected high-resolution transmission electron microscopy operated at 80?keV allows visualization of the formation of nanometre-sized hollow protrusions on the nanotube sidewall at the atomic level in real time at ambient temperature. Our direct observations and theoretical modelling demonstrate that the nanoprotrusions are formed in three stages: (i) metal-assisted d...

2011-01-01

144

Hypomethylation and induction of retinoic acid receptor beta 2 by concurrent action of adenosine analogues and natural compounds in breast cancer cells  

British Library Electronic Table of Contents (United Kingdom)

DNA methylation is considered as a potential cause of aberrations in regulation of gene expression during carcinogenesis. Therefore, changes in DNA methylation patterns may be targets for chemoprevention. In the present study, we investigated effects of all-trans retinoic acid (ATRA), vitamin D3, and resveratrol alone and in combination with adenosine analogues: 2-chloro-2'-deoxyadenosine (2CdA) and 9-beta-d-arabinosyl-2-fluoroadenine (F-ara-A), on methylation and expression of retinoic acid receptor beta 2 (RARbeta2) in MCF-7 and MDA-MB-231 breast cancer cell lines. Alterations in methylation and expression levels after treatment of cells with the tested compounds were evaluated by methylation-sensitive restriction analysis (MSRA) and real-time PCR, respectively. RARbeta2 promoter in the ...

2010-01-01

145

Triphenylmethylphosphonium cation distribution as a measure of hormone-induced alterations in white adipocyte membrane potential  

Energy Technology Data Exchange (ETDEWEB)

Triphenylmethylphosphonium (TPMP+) partitions into the mitochondrial and cytosolic compartments in the rat white adipocyte in a potential-dependent fashion. The relationship between (/sup 3/H)TPMP+ distribution, intracellular cAMP generation and lipolysis in response to hormones and cAMP-mimetic compounds was examined. Half-maximal (/sup 3/H)TPMP+ efflux and glycerol release were produced by 15 and 9 nM adrenocorticotropin, 170 and 110 nM 1-epinephrine, 70 and 27 microM isobutylmethylxanthine and 800 and 750 microM dibutyryl cAMP, respectively. Hormone-stimulated cAMP generation was also correlated with (/sup 3/H)TPMP+ efflux and lipolysis in terms of concentration dependency. In kinetic experiments, glycerol release and (/sup 3/H)TPMP+ efflux in response to adrenocorticotropin or cholera toxin proceeded over a similar time course, whereas an earlier rise in cAMP generation was detected. The depolarizing effect of lipolytic compounds was localized to the ...

1982-01-01

146

Helminthosporium maydis T toxin decreased calcium transport into mitochondria of susceptible corn  

Energy Technology Data Exchange (ETDEWEB)

The effects of purified Helminthosporium maydis T (HmT) toxin on active Ca/sup 2 +/ transport into isolated mitochondria and microsomal vesicles were compared for a susceptible (T) and a resistant (N) strain of corn (Zea mays). ATP, malate, NADH, or succinate could drive /sup 45/Ca/sup 2 +/ transport into mitochondria of corn roots. Ca/sup 2 +/ uptake was dependent on the proton electrochemical gradient generated by the redox substrates or the reversible ATP synthetase, as oligomycin inhibited ATP-driven CA/sup 2 +/ uptake while KCN inhibited transport driven by the redox substrates. Purified native HmT toxin completely inhibited Ca/sup 2 +/ transport into T mitochondria at 5 to 10 nanograms per milliliter while transport into N mitochondria was decreased slightly by 100 nanograms per milliliter toxin. Malate-driven Ca/sup 2 +/ transport in T mitochondria was frequently more inhibited by 5 nanograms per milliliter toxin than succinate or ATP-driven Ca/sup 2 +/ uptake. However, ...

1984-04-01

147

Trans-generational radiation-induced chromosomal instability in the female enhances the action of chemical mutagens  

Energy Technology Data Exchange (ETDEWEB)

Genomic instability can be produced by ionising radiation, so-called radiation-induced genomic instability, and chemical mutagens. Radiation-induced genomic instability occurs in both germinal and somatic cells and also in the offspring of irradiated individuals, and it is characterised by genetic changes including chromosomal rearrangements. The majority of studies of trans-generational, radiation-induced genomic instability have been described in the male germ line, whereas the authors who have chosen the female as a model are scarce. The aim of this work is to find out the radiation-induced effects in the foetal offspring of X-ray-treated female rats and, at the same time, the possible impact of this radiation-induced genomic instability on the action of a chemical mutagen. In order to achieve both goals, the quantity and quality of chromosomal damage were analysed. In order to detect trans-generational genomic instability, a total of 4806 metaphases from foetal tissues from the ...

2008-04-02

148

Toxicological safety evaluation of biomolecules and materials transformed by gamma irradiation  

Energy Technology Data Exchange (ETDEWEB)

In the bacterial reversion assay with S. typhimurium TA98, TA100, TA1535 and TA1537, gamma irradiated hyaluronic acid (10 and 50 kGy) did not induce a significant increase in the number of revertant colonies in the presence of S9 metabolic activation system. In chromosomal aberration tests with CHO cells, gamma irradiated hyaluronic acid (10 and 50 kGy) did not result in an increase in the frequency of chromosomal aberrations. In vivo mouse micronucleus assay, gamma irradiated hyaluronic acid (10 and 50 kGy) did not show an increase in the frequency of polychromatic erythrocytes with micronuclei. These results indicate that hyaluronic acids irradiated at 10 and 50 kGy did not show any genotoxic effects under these experimental conditions. In order to evaluate their possible subacute toxicity, the male and female of ICR mouse were given to methanol extract of 50 kGy irradiated red ginseng and 20 kGy irradiated water extract of mistletoe for ...

2010-01-15

149

PROGRESS IN BEAM FOCUSING AND COMPRESSION FOR WARM-DENSE MATTER EXPERIMENTS  

Energy Technology Data Exchange (ETDEWEB)

The Heavy-Ion Fusion Sciences Virtual National Laboratory is pursuing an approach to target heating experiments in the Warm Dense Matter regime, using spacecharge-dominated ion beams that are simultaneously longitudinally bunched and transversely focused. Longitudinal beam compression by large factors has beendemonstrated in the Neutralized Drift Compression Experiment (NDCX) with controlledramps and forced neutralization. Using an injected 30-mA K+ ion beam with initialkinetic energy 0.3 MeV, axial compression leading to ~;;50-fold current amplification andsimultaneous radial focusing to beam radii of a few mm have led to encouraging energy deposition approaching the intensities required for eV-range target heating experiments. We discuss the status of several improvements to our Neutralized Drift Compression Experiment and associated beam diagnostics that are under development to reach the necessary higher beam intensities, including: (1) greater axial compression via a longer ...

2008-09-25

150

New discoveries in prostate cancer pathogenesis  

International Nuclear Information System (INIS)

Background. Through PSA screening the rate of prostate cancers detected at an early stage has increased significantly; thus a decrease in mortality can be expected in the near future. Despite all scientific efforts, however, the molecular mechanisms underlying the development and progression of prostate cancer remain poorly understood. Prostate cancer is a disease of aging men and epidemiological evidence supports a major contribution to its development through diet, lifestyle and environmental factors. Genetic instability is the basic phenomenon of tissue cell cancerisation. This instability can be hereditary or due to mutations and other chromosomal aberrations acquired during life. In recent years a large number of interesting data have been collected which show the relationships between focal atrophy and genetic instability of the prostate epithelia. Atrophy can be the result of prostatitis, ischemia as well as of oxidative stress (diet). Several chromosomal ...

151

Gel-based proteomics of liver cancer progression in rat.  

Science.gov (United States)

A significant challenge in proteomics biomarker research is to identify the changes that are of highest diagnostic interest, among the many unspecific aberrations associated with disease burden and inflammation. In the present study liver tissue specimens (n=18) from six experimental stages were collected from the resistant hepatocyte (RH) rat model of liver cancer and analyzed by 2D DIGE. The study included triplicates of regenerating liver, control "sham-operated" liver, three distinct premalignant stages and hepatomas. Out of 81 identified proteins two-thirds were differentially abundant in rat hepatomas compared to control rat liver and, secondly, the majority of proteins were also changed in precursor stages. This underscores the importance of adequate control samples in explorative cancer biomarker research. We confirm several proteomic changes previously identified in human hepatocellular carcinoma (HCC) and we identify novel candidate proteomic ...

2011-06-06

152

Deficiency of the housekeeping gene hypoxanthine-guanine phosphoribosyltransferase (HPRT) dysregulates neurogenesis.  

Science.gov (United States)

Neuronal transcription factors play vital roles in the specification and development of neurons, including dopaminergic (DA) neurons. Mutations in the gene encoding the purine biosynthetic enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT) cause the resulting intractable and largely untreatable neurological impairment of Lesch-Nyhan disease (LND). The disorder is associated with a defect in basal ganglia DA pathways. The mechanisms connecting the purine metabolic defect and the central nervous system (CNS) phenotype are poorly understood but have been presumed to reflect a developmental defect of DA neurons. We have examined the effect of HPRT deficiency on the differentiation of neurons in the well-established human (NT2) embryonic carcinoma neurogenesis model. We have used a retrovirus expressing a small hairpin RNA (shRNA) to knock down HPRT gene expression and have examined the expression of a number of transcription factors essential for neuronal differentiation and ...

2009-08-11

153

DNA rearrangements from #gamma#-irradiated normal human fibroblasts preferentially occur in transcribed regions of the genome  

International Nuclear Information System (INIS)

Full text: DNA rearrangement events leading to chromosomal aberrations are central to ionizing radiation-induced cell death. Although DNA double-strand breaks are probably the lesion that initiates formation of chromosomal aberrations, little is understood about the molecular mechanisms that generate and modulate DNA rearrangement. Examination of the sequences that flank sites of DNA rearrangement may provide information regarding the processes and enzymes involved in rearrangement events. Accordingly, we developed a method using inverse PCR that allows the detection and sequencing of putative radiation-induced DNA rearrangements in defined regions of the human genome. The method can detect single copies of a rearrangement event that has occurred in a particular region of the genome and, therefore, DNA rearrangement detection does not require survival and continued multiplication of the affected cell. Ionizing radiation-induced DNA ...

2003-08-17

154

Nonphotochemical Hole-Burning Imaging Studies of in vitro Carcinoma and Normal Cells Utilizing a Mitochondrial Specific Dye  

Energy Technology Data Exchange (ETDEWEB)

Low temperature Nonphotochemical Hole Burning (NPHB) Spectroscopy of the dye rhodamine 800 (MF680) was applied for the purpose of discerning differences between cultured normal and carcinoma ovarian surface epithelial (OSE) cells. Both the cell lines were developed and characterized at the Mayo Clinic (Rochester, MN), with the normal cell line having been transfected with a strain of temperature sensitive Simian Virus 40 Large T Antigen (SV40) for the purpose of extending the life of the cell culture without inducing permanent changes in the characteristics of the cell line. The cationic lipophilic fluorophore rhodamine 800 preferentially locates in in situ mitochondria due to the high lipid composition of mitochondria and the generation of a large negative membrane potential (relative to the cellular cytoplasm) for oxidative phosphorylation. Results presented for NPHB of MF680 located in the cells show significant differences between the two cell lines. The results are interpreted on ...

2002-06-27

155

Nonphotochemical Hole-Burning Imaging Studies of In Vitro Carcinoma and Normal Cells Utilizing a Mitochondrial Specific Dye  

Energy Technology Data Exchange (ETDEWEB)

Low temperature Nonphotochemical Hole Burning (NPHB) Spectroscopy of the dye rhodamine 800 (MF680) was applied for the purpose of discerning differences between cultured normal and carcinoma ovarian surface epithelial (OSE) cells. Both the cell lines were developed and characterized at the Mayo Clinic (Rochester, MN), with the normal cell line having been transfected with a strain of temperature sensitive Simian Virus 40 Large T Antigen (SV40) for the purpose of extending the life of the cell culture without inducing permanent changes in the characteristics of the cell line. The cationic lipophilic fluorophore rhodamine 800 preferentially locates in in situ mitochondria due to the high lipid composition of mitochondria and the generation of a large negative membrane potential (relative to the cellular cytoplasm) for oxidative phosphorylation. Results presented for NPHB of MF680 located in the cells show significant differences between the two cell lines. The results are interpreted on ...

2002-08-01

156

mtDNA mutation C1494T, haplogroup A, and hearing loss in Chinese  

British Library Electronic Table of Contents (United Kingdom)

Mutation C1494T in mitochondrial 12S rRNA gene was recently reported in two large Chinese families with aminoglycoside-induced and nonsyndromic hearing loss (AINHL) and was claimed to be pathogenic. This mutation, however, was first reported in a sample from central China in our previous study that was aimed to reconstruct East Asian mtDNA phylogeny. All these three mtDNAs formed a subclade defined by mutation C1494T in mtDNA haplogroup A. It thus seems that mutation C1494T is a haplogroup A-associated mutation and this matrilineal background may contribute a high risk for the penetrance of mutation C1494T in Chinese with AINHL. To test this hypothesis, we first genotyped mutation C1494T in 553 unrelated individuals from three regional Chinese populations and performed an extensive search ...

2006-01-01

157

Submitochondrial distribution of cAMP in its incubation with rat liver mitochondria  

Energy Technology Data Exchange (ETDEWEB)

When labeled cAMP is incubated with isolated mitochondria from rat liver, it penetrates not only through the outer membrane of the mitochondria but also into the mitoplasts, where it is accumulated chiefly in the matrix. Damage to the mitochondrial membrane by freezing-thawing promotes not an influx but an efflux of cAMP out of the mitoplasts. A substantial part of the labeled nucleotide in all the investigated submitochondrial fractions was identified as intact cAMP by the method of thin-layer chromatography. The transport of cAMP into the mitochondria can explain the activation of their functions by the hormones that activate cytoplasmic adenylate cyclase and by extramitochondrial (cytosol) cAMP, as well as the presence of cAMP-dependent protein kinase and cAMP-phosphodiesterase in the mitochondria.

1986-03-20

158

Molecular phylogenetic relationships and phenotypic diversity in miniaturized toadlets, genus Brachycephalus (Amphibia: Anura: Brachycephalidae)  

British Library Electronic Table of Contents (United Kingdom)

Toadlets of the genus Brachycephalus are endemic to the Atlantic rainforests of southeastern and southern Brazil. The 14 species currently described have snout-vent lengths less than 18mm and are thought to have evolved through miniaturization: an evolutionary process leading to an extremely small adult body size. Here, we present the first comprehensive phylogenetic analysis for Brachycephalus, using a multilocus approach based on two nuclear (Rag-1 and Tyr) and three mitochondrial (Cyt b, 12S, and 16S rRNA) gene regions. Phylogenetic relationships were inferred using a partitioned Bayesian analysis of concatenated sequences and the hierarchical Bayesian method (BEST) that estimates species trees based on the multispecies coalescent model. Individual gene trees showed conflict and also va...

2011-01-01

159

Mitochondrial sequestration of BCECF after ester loading in the giant alga Chara australis  

British Library Electronic Table of Contents (United Kingdom)

Summary. Ratiometric fluorescent dyes are often used to monitor free ion concentrations in vivo, especially in cells that are recalcitrant to transformation with genetically encoded fluorescent markers. Although intracellular dye distributions are often found to be cytosolic, dye localisation has often not been examined in detail. We began exploring the use of BCECF (2?,7?-bis(2-carboxyethyl)-5(6)-carboxyfluorescein) to monitor pH in the giant alga Chara australis and discovered that younger leaf cells could be loaded using the acetoxymethyl ester of BCECF. However, we were puzzled to find in microphotometric measurements that the fluorescence ratio appeared insensitive to manipulations affecting cytosolic pH. Confocal imaging of C. australis cells loaded with BCECF showed an accumulation ...

2007-01-01

160

Mitochondria-localized NAD biosynthesis by nicotinamide mononucleotide adenylyltransferase in Jerusalem artichoke (Helianthus tuberosus L.) heterotrophic tissues  

British Library Electronic Table of Contents (United Kingdom)

Current studies in plants suggest that the content of the coenzyme NAD is variable and potentially important in determining cell fate. In cases that implicate NAD consumption, re-synthesis must occur to maintain dinucleotide pools. Despite information on the pathways involved in NAD synthesis in plants, the existence of a mitochondrial nicotinamide mononucleotide adenylyltransferase (NMNAT) activity which catalyses NAD synthesis from nicotinamide mononucleotide (NMN) and ATP has not been reported. To verify the latter assumed pathway, experiments with purified and bioenergetically active mitochondria prepared from tubers of Jerusalem artichoke (Helianthus tuberosus L.) were performed. To determine whether NAD biosynthesis might occur, NMN was added to Jerusalem artichoke mitochondria (JAM)...

2011-01-01

161

Leishmania major ascorbate peroxidase overexpression protects cells against reactive oxygen species-mediated cardiolipin oxidation  

British Library Electronic Table of Contents (United Kingdom)

Heme peroxidases are a class of multifunctional redox-active proteins found in all organisms. We recently cloned, expressed, and characterized an ascorbate peroxidase from Leishmania major (LmAPX) that was capable of detoxifying hydrogen peroxide. Localization studies using green fluorescent protein fusions revealed that LmAPX was localized within the mitochondria by its N-terminal signal sequence. Subcellular fractionation analysis of the cell homogenate by the Percoll density-gradient method and subsequent Western blot analysis with anti-LmAPX antibody further confirmed the mitochondrial localization of mature LmAPX. Submitochondrial fractionation analysis showed that the mature enzyme (?3.6?kDa shorter than the theoretical value of the whole gene) was present in the intermembrane space ...

2008-01-01

162

Identification of pork derivatives in food products by species-specific polymerase chain reaction (PCR) for halal verification  

British Library Electronic Table of Contents (United Kingdom)

Pork identification in four types of food products, which are sausages and the casings, bread and biscuits, using species-specific polymerase chain reaction (PCR) detection of a conserved region in the mitochondrial (mt) 12S ribosomal RNA (rRNA) gene was developed. Genomic DNA of the food products were successfully extracted except for the casing samples, where no genomic DNA was detected. The extracted genomic DNA was then subjected to PCR amplification targeting the specific regions of the 12S rRNA gene. The genomic DNA from the food products were found to be of good quality and produced clear PCR products on the amplification of 12S rRNA gene of 387 base pairs (bp) from pork species. The species-specific PCR identification yielded excellent results for identification of pork derivatives...

2007-01-01

163

Effects of Valproic Acid on Organic Acid Metabolism in Children: A Metabolic Profiling Study  

British Library Electronic Table of Contents (United Kingdom)

Young children are at increased risk for valproic acid (VPA) hepatotoxicity. Urinary organic acid profiles, as a surrogate of mitochondrial function, were obtained in children 1.9 to 17.3 years of age (n = 52) who were undergoing treatment with VPA for seizure disorders. Age-matched patients receiving treatment with carbamazepine (CBZ; n = 50) and healthy children not undergoing treatment (n = 22) served as controls. Age-related changes in organic acid profiles were observed in all three groups. Although the untreated and CBZ control groups were indistinguishable from each other with respect to the principal-component analysis (PCA) score plots of the subjects, a distinct boundary was apparent between the VPA and each of the control groups. Interindividual variability was observed in the V...

2011-01-01

164

DNA barcoding as a tool for species identification in three forensic wildlife cases in South Africa  

British Library Electronic Table of Contents (United Kingdom)

Poaching of wildlife animals for subsistence and commercial purposes has lead to population declines in Africa. In forensic cases, a need exists to identify the species of origin of carcasses, meat or blood. In the study presented here, the mitochondrial COI gene was sequenced to determine the species of unknown samples in three suspect South African forensic wildlife cases. In two cases the unknown samples were identified as originating from domestic cattle (Bos taurus) and in the third case the sample was identified as common reedbuck (Redunca arundinum). This is the first report of the COI sequence of common reedbuck. The study highlights the need for accurate wildlife reference material from each country in order to convict wildlife cases.

2011-01-01

165

Changes in Energy Metabolism and Antioxidant Defense Systems During Seed Germination of the Weed Species Ipomoea triloba L. and the Responses to Allelochemicals  

British Library Electronic Table of Contents (United Kingdom)

The relationships between changes in energy metabolism and the antioxidant defense system in the weed species Ipomoea triloba L. during seed germination and early seedling growth were investigated. The effects of some common allelochemicals on these parameters also were studied. Respiratory activity and the activities of alcohol dehydrogenase, superoxide dismutase, catalase, guaicol peroxidase, ascorbate peroxidase, glutathione reductase, and lipoxygenase were measured. Mitochondrial oxidative phosphorylation resumed shortly after the seed imbibition period, as indicated by considerable KCN-sensitive respiratory activity in embryos of I. triloba. The occurrence of superoxide dismutase, catalase, guaicol peroxidase, and lipoxygenase activities in the embryos, along with significant KCN-inse...

2011-01-01

166

Biological and morphological characterization of human neonatal fibroblast cell culture B-HNF-1  

British Library Electronic Table of Contents (United Kingdom)

In the present study, human neonatal fibroblasts were isolated from a two-month-old human male. The purpose of the present investigation was the analysis of the morphology (light and transmission electron microscopy), karyotype and growth characteristics of the human neonatal fibroblast cell culture B-HNF-1. Moreover, STR typing and mitochondrial DNA amplification and sequencing was also performed. Analysis of chromosomes count showed that B-HNF-1 cell culture is diploid and has normal male karyotype 46, XY, which was stable during cultivation. The transmission electron microscopy demonstrated the ultra-structure of the B-HNF-1 cells; they have typical morphological features of proteosynthesis-active cells. Large number of fibroblasts bearing different shapes and surface characteristics ad...

2010-01-01

167

Association of the polymorphism of the CAG repeat in the mitochondrial DNA polymerase gamma gene (POLG) with testicular germ-cell cancer  

British Library Electronic Table of Contents (United Kingdom)

Background: A possible association between the polymorphic CAG repeat in the DNA polymerase gamma (POLG) gene and the risk of testicular germ-cell tumours (TGCT) was investigated in this study. The hypothesis was prompted by an earlier preliminary study proposing an association of the absence of the common 10-CAG-long POLG allele with testicular cancer as well as previously reported in some European populations' association with male subfertility, which is a condition carrying an increased risk of TGCT. Patients and methods: The number of CAG repeats in both POLG alleles was established in 243 patients with TGCT and in 869 controls by the analysis of the genomic DNA fragment. Results: A significantly higher proportion of men homozygous allele of other than the common 10 CAG repeats was fou...

2008-01-01

168

Anthracenedione derivatives as anticancer agents isolated from secondary metabolites of the mangrove endophytic fungi.  

Science.gov (United States)

In this article, we report anticancer activity of 14 anthracenedione derivatives separated from the secondary metabolites of the mangrove endophytic fungi Halorosellinia sp. (No. 1403) and Guignardia sp. (No. 4382). Some of them inhibited potently the growth of KB and KBv200 cells, among which compound 6 displayed strong cytotoxicity with IC(50) values of 3.17 and 3.21 microM to KB and KBv200 cells, respectively. Furthermore, we demonstrate that the mechanism involved in the apoptosis induced by compound 6 is probably related to mitochondrial dysfunction. Additionally, the structure-activity relationships of these compounds are discussed. PMID:20479985

2010-04-23

169

Performance characterization of a volumetric breast ultrasound scanner  

Science.gov (United States)

The purpose of this project was to design, build, and characterize the performance of a volume breast ultrasound (VBUS) scanner that images the pendant breast. VBUS scanner design includes a: 1) clinical ultrasound scanner and transducer; 2) scanning table with a hole for the pendant breast; 3) rotational gantry; 4) probe mounting assembly; 5) compressionless breast stabilization device; 6) acquisition, control, reconstruction, and display software. Performance assessment characterized a variety of parameters including: spatial resolution, uniformity, and distortion using high and low contrast test objects in both horizontal and vertical scanning modes. The VBUS scanner modules have been constructed and initial performance evaluated. Approximately 300 scans are acquired over 360 degrees in 18 seconds. Reconstruction requires 25 ms per slice. Test object images depicted hyper- and hypo-echoic masses and demonstrated good resolution, soft tissue contrast and reduced speckle compared to ...

2007-03-01

170

Parametric Resonance Ionization Cooling and Reverse Emittance Exchange for Muon Collider  

Energy Technology Data Exchange (ETDEWEB)

Two methods to cool muon beams deeply below the limit conventionally established for the ionization cooling are proposed. In Phase Ionization Cooling (PIC), the beam is focused at wedge absorber plates each half of particle oscillation period by imposing a weak parametric resonance along the beam path. The resonance growth of particle amplitude is surmounted by the ionization cooling. At optimum, such arrangement results in reduction of each of two transverse emittances by an order of value in addition to the preceding 6D ionization cooling. Next, resonance focusing and transverse cooling can be continued in the regime of a fast Reverse Emittance Exchange (REMEX). Here, the sign of the absorber wedge is opposite to PIC while the dispersion increased. REMEX to be accompanied by the bunch lengthening and acceleration in order to maintain the relative energy spread at an appropriate level. The limitations due to energy straggling in absorber will be evaluated, and possibilities of beam ...

2005-09-18

171

Multistep process of neoplastic transformation of normal human fibroblasts by 60Co gamma rays and Harvey sarcoma viruses  

Energy Technology Data Exchange (ETDEWEB)

As reported previously (Namba et al., 1985), normal human fibroblasts were transformed by 60Co gamma-ray irradiation into immortal cells with abnormal karyotypes. These transformed cells (KMST-6), however, showed a low cloning efficiency in soft agar and no transplantability. However, upon treatment with Harvey murine sarcoma virus (Ha-MSV), the cells acquired elevated clonability in soft agar and transplantability in nude mice. Ha-MSV alone, however, did not convert normal human fibroblasts into either immortal or tumorigenic cells. The Ha-MSV-transformed KMST-6 cells showed an enhanced expression of the ras oncogene, but normal and 60Co gamma-ray-transformed cells did not. Our current data suggest that gamma rays worked against normal human cells as an initiator, giving rise to chromosome aberrations and immortality, and that Ha-MSV, probably through its ras oncogene, played a role in the progression of the malignant cell population to a more malignant one ...

1986-03-15

172

Mapping cis-Regulatory Domains in the Human Genome UsingMulti-Species Conservation of Synteny  

Energy Technology Data Exchange (ETDEWEB)

Our inability to associate distant regulatory elements with the genes that they regulate has largely precluded their examination for sequence alterations contributing to human disease. One major obstacle is the large genomic space surrounding targeted genes in which such elements could potentially reside. In order to delineate gene regulatory boundaries we used whole-genome human-mouse-chicken (HMC) and human-mouse-frog (HMF) multiple alignments to compile conserved blocks of synteny (CBS), under the hypothesis that these blocks have been kept intact throughout evolution at least in part by the requirement of regulatory elements to stay linked to the genes that they regulate. A total of 2,116 and 1,942 CBS>200 kb were assembled for HMC and HMF respectively, encompassing 1.53 and 0.86 Gb of human sequence. To support the existence of complex long-range regulatory domains within these CBS we analyzed the prevalence and distribution of chromosomal aberrations ...

2005-06-13

173

Epigenomic disruption: the effects of early developmental exposures.  

Science.gov (United States)

Through DNA methylation, histone modifications, and small regulatory RNAs the epigenome systematically controls gene expression during development, both in utero and throughout life. The epigenome is also a very reactive system; its labile nature allows it to sense and respond to environmental perturbations to ensure survival during fetal growth. This pliability can lead to aberrant epigenetic modifications that persist into later life and induce numerous disease states. Endocrine-disrupting compounds (EDCs) are ubiquitous chemicals that interfere with growth and development. Several EDCs also interfere with epigenetic programming. The investigation of the epigenotoxic effects of bisphenol A (BPA), an EDC used in the production of plastics and resins, has further raised concern over the impact of EDCs on the epigenome. Using the Agouti viable yellow (A(vy)) mouse model, dietary BPA exposure was shown to hypomethylate both the A(vy) and the Cabp(IAP) metastable ...

2010-10-01

174

Broad-band stigmatic spectrograph for the soft x-ray range  

International Nuclear Information System (INIS)

We describe a panoramic stigmatic spectrograph comprising a grazing-incidence toroidal mirror and a large-aperture free-standing transmission diffraction grating (5000 lines mm-1 ). Two spectrograph versions were constructed, with grazing angles of 7.6 and 40 and the short-wavelength spectral limits near 4 and 1.5 nm. The spectrograph aberrations were studied by numerical ray tracing. The spectrograph was used to record line and quasi-continuous spectra (1.5 - 30 nm) of multiply charged ions in a plasma generated by the second-harmonic pulses of an yttrium aluminate laser (Q = 0.15 J, ? = 5 ns, ? = 0.54 ?m, repetition rate = 0.5 Hz). In combination with a laser-produced plasma radiation source, the arrangement was used to characterise soft x-ray optical components and to generate collimated beams of polarised radiation in the 14 - 20 nm range. (laser applications and other topics in quantum electronics)

1998-09-30

175

Application of the histone deacetylase inhibitors for the treatment of endometriosis: histone modifications as pathogenesis and novel therapeutic target.  

Science.gov (United States)

BACKGROUND Accumulating evidence suggests that various epigenetic aberrations play definite roles in the pathogenesis of endometriosis. We investigated the histone acetylation status in endometriosis and the application of the histone deacetylase inhibitors (HDACIs) for the treatment of endometriosis. METHODS The levels of acetylated histones in the endometriotic cyst stromal cells (ECSCs) and normal endometrial stromal cells (NESCs) were evaluated. The effects of the HDACIs on cell proliferation, the cell cycle, apoptosis of ECSCs and NESCs, and the expression of genes related to these cellular events were investigated. The effects of HDACIs on histone acetylation in chromatin of the promoter region of the cell cycle regulatory genes in ECSCs were also investigated. RESULTS The acetylated histone levels were significantly lower in ECSCs than in NESCs (P endometriosis and that HDACIs reactivated epigenetically silenced genes, resulting in the suppression of cell ...

2011-06-29

176

Age at onset in Huntington?s disease is modified by the autophagy pathway: implication of the V471A polymorphism in Atg7  

British Library Electronic Table of Contents (United Kingdom)

Huntington?s disease (HD) is caused by an expansion of a polyglutamine repeat of more than 35?units in the huntingtin protein. The expanded repeat length is inversely correlated with the age at onset (AAO); however, additional genetic factors apart from the expanded CAG repeat length can modify the course and the AAO in HD. Aberrations in macroautophagy have been observed in Huntington, Alzheimer, Parkinson, motor neuron and prion diseases. Therefore, we hypothesized that polymorphisms in autophagy-related (Atg) genes might contribute to the variation in the AAO. We initially tested eight single nucleotide polymorphisms in five Atg genes (Atg3, Atg5, Atg7, Atg16L1 and Beclin-1) for their frequency of ?1%. Subsequently, we investigated the polymorphisms Atg7 V471A and Atg16L1 T281A for a di...

2010-01-01

177

A single amino acid substitution results in a retinoblastoma protein defective in phosphorylation and oncoprotein binding  

International Nuclear Information System (INIS)

The authors have previously identified a small-cell lung cancer cell line (NCI-H209) that expresses an aberrant, underphosphorylated form of the retinoblastoma protein RB1. Molecular analysis of RB1 mRNA from this cell line revealed a single point mutation within exon 21 that resulted in a nonconservative amino acid substitution (cysteine to phenylalanine) at codon 706. Stable expression of this mutant RB1 cDNA in a human cell line lacking endogenous RB1 demonstrated that this amino acid change was sufficient to inhibit phosphorylation. In addition, this cysteine-to-phenylalanine substitution also resulted in loss of RB1 binding to the simian virus 40 large tumor and adenovirus E1A transforming proteins. These results confirm the importance of exon 21 coding sequences and suggest that the cysteine residue at codon 706 may play a role in achieving a specific protein conformation essential for protein-protein interactions.

178

?Tasting and wasting?? behavior in non-human primates: Aberrant behavior or normal behavior in ?times of plenty??  

British Library Electronic Table of Contents (United Kingdom)

The purpose of this study was to develop a foraging model that engenders large meals. Eight free-feeding baboons were first given periodic access to a chocolate sugar-coated candy (M & Ms?) and then a jelly sugar-coated candy (Skittles?). Baboons had access to food 24?h each day, but they had to complete a two-phase operant procedure in order to eat. Responding on one lever during a 30-min appetitive phase was required before animals could start a consumption phase, where responding on another lever led to food delivery, i.e., a meal. 3?days a week for 8 or 9?weeks baboons received candy during the first meal and then food pellets were available: a 2?month interval when only pellets were available separated periods of candy access. All baboons ate as much candy in the single candy meal as ...

2006-01-01

179

Monitoring of DNA and cytogenetic damage in lymphocytes from persons with skin cancer diseases  

International Nuclear Information System (INIS)

There is a lot of interest in the studies that would help to understand whether there is a casual association between cancer and various types of molecular or cytogenetic damage detected in human cells. One major oncogenesis process is activation of proto-oncogenes by point mutations or chromosomal translocation. There are substantial evidence that indicates that the loss of heterozygosity of certain chromosomes is involved in human cancerogenesis. Our study aimed to elicit the possible association between cancer and DNA and cytogenetic abnormalities induced in lymphocytes of people bearing various categories of skin cancer cells. Fresh blood was collected by venipuncture from 25 individuals (including nine prior to cancer treatment). All patients were nonsmoking males, however 42.3 % of them were former smokers. Blood samples were divided into two parts and in the first part of samples cytogenetic studies were performed immediately, while from the second part lymphocytes were isolated ...

2004-11-01

180

Strikingly different penetrance of LHON in two Chinese families with primary mutation G11778A is independent of mtDNA haplogroup background and secondary mutation G13708A  

Energy Technology Data Exchange (ETDEWEB)

The penetrance of Leber's hereditary optic neuropathy (LHON) in families with primary mitochondrial DNA (mtDNA) mutations is very complex. Matrilineal and nuclear genetic background, as well as environmental factors, have been reported to be involved in different affected pedigrees. Here we describe two large Chinese families that show a striking difference in the penetrance of LHON, in which 53.3% and 15.0% of members were affected (P < 0.02), respectively. Analysis of the complete mtDNA genome of the two families revealed the presence of the primary mutation G11778A and several other variants suggesting the same haplogroup status G2a. The family with higher penetrance contained a previously described secondary mutation G13708A, which presents a polymorphism in normal Chinese samples and does not affect in vivo mitochondrial oxidative metabolism as described in a previous study. Evolutionary analysis failed to indicate any ...

2008-08-25

181

Strikingly different penetrance of LHON in two Chinese families with primary mutation G11778A is independent of mtDNA haplogroup background and secondary mutation G13708A  

International Nuclear Information System (INIS)

The penetrance of Leber's hereditary optic neuropathy (LHON) in families with primary mitochondrial DNA (mtDNA) mutations is very complex. Matrilineal and nuclear genetic background, as well as environmental factors, have been reported to be involved in different affected pedigrees. Here we describe two large Chinese families that show a striking difference in the penetrance of LHON, in which 53.3% and 15.0% of members were affected (P < 0.02), respectively. Analysis of the complete mtDNA genome of the two families revealed the presence of the primary mutation G11778A and several other variants suggesting the same haplogroup status G2a. The family with higher penetrance contained a previously described secondary mutation G13708A, which presents a polymorphism in normal Chinese samples and does not affect in vivo mitochondrial oxidative metabolism as described in a previous study. Evolutionary analysis failed to indicate any putatively ...

2008-08-25

182

Reactive biomolecular divergence in genetically altered yeast cells and isolated mitochondria as measured by biocavity laser spectroscopy : a rapid diagnostic method for studying cellular responses to stress and disease.  

Energy Technology Data Exchange (ETDEWEB)

We report an analysis of four strains of baker's yeast (Saccharomyces cerevisiae) using biocavity laser spectroscopy. The four strains are grouped in two pairs (wild type and altered), in which one strain differs genetically at a single locus, affecting mitochondrial function. In one pair, the wild-type rho+ and a rho0 strain differ by complete removal of mitochondrial DNA (mtDNA). In the second pair, the wild-type rho+ and a rho- strain differ by knock-out of the nuclear gene encoding Cox4, an essential subunit of cytochrome c oxidase. The biocavity laser is used to measure the biophysical optic parameter Deltalambda, a laser wavelength shift relating to the optical density of cell or mitochondria that uniquely reflects its size and biomolecular composition. As such, Deltalambda is a powerful parameter that rapidly interrogates the biomolecular state of single cells and mitochondria. Wild-type cells and mitochondria produce ...

2006-12-01

183

Paraquat induces oxidative stress and neuronal cell death; neuroprotection by water-soluble Coenzyme Q_1_0  

International Nuclear Information System (INIS)

Neuronal cell death induced by oxidative stress is correlated with numerous neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), and stroke. The causes of sporadic forms of age-related neurodegenerative diseases are still unknown. Recently, a correlation between paraquat exposure and neurodegenerative diseases has been observed. Paraquat, a nonselective herbicide, was once widely used in North America and is still routinely used in Taiwan. We have used differentiated Human Neuroblastoma (SHSY-5Y) cells as an in vitro model to study the mechanism of cell death induced by paraquat. We observed that paraquat-induced oxidative stress in differentiated SHSY-5Y cells as indicated by an increase in the production of cellular reactive oxygen species (ROS). Furthermore, apoptosis was evident as indicated by cellular and nuclear morphology and DNA fragmentation. Interestingly, pretreatment of SHSY-5Y cells with water-soluble Coenzyme Q_1_0 (CoQ_1_0) before ...

2004-11-15

184

Mitochondrial sequestration of BCECF after ester loading in the giant alga Chara australis.  

Science.gov (United States)

Ratiometric fluorescent dyes are often used to monitor free ion concentrations in vivo, especially in cells that are recalcitrant to transformation with genetically encoded fluorescent markers. Although intracellular dye distributions are often found to be cytosolic, dye localisation has often not been examined in detail. We began exploring the use of BCECF (2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein) to monitor pH in the giant alga Chara australis and discovered that younger leaf cells could be loaded using the acetoxymethyl ester of BCECF. However, we were puzzled to find in microphotometric measurements that the fluorescence ratio appeared insensitive to manipulations affecting cytosolic pH. Confocal imaging of C. australis cells loaded with BCECF showed an accumulation of the dye in two locations: (1) on the outside of the chloroplasts in irregularly shaped stationary bodies; (2) within 1-1.5 mum structures that moved rapidly with the pericellular cytoplasmic streaming. ...

2007-12-19

185

Characterization of neurotoxic effects of NMDA and the novel neuroprotection by phytopolyphenols in mice.  

Science.gov (United States)

Excitotoxicity plays a major role in various neurological disorders. In this study, we explored the behavioral and neurotoxic effects of intraventricular NMDA administration in mice. After NMDA injection, acute seizures were followed by impairments in locomotor activity, motor performance on a rotarod, and climbing ability. Mice killed 1 day after NMDA administration showed increased synaptosomal reactive oxygen species ROS production and calcium concentration and decreased mitochondrial membrane potential, mitochondrial reductase activities, and neuronal membrane Na+, K+ -ATPase and mg2+ -ATPase activities. One and 3 days after excitotoxic injury, Golgi stains showed that dendritic length and spine density were significantly decreased in neurons of the hippocampal dentate gyrus. Some mice received honokiol, tea polyphenol plus memantine, and honokiol plus memantine prior to NMDA treatment; the occurrence of generalized seizures was attenuated, ...

2010-08-01

186

Sympatric Distribution of Three Human Taenia Tapeworms Collected between 1935 and 2005 in Korea  

Science.gov (United States)

Taeniasis has been known as one of the prevalent parasitic infections in Korea. Until recently, Taenia saginata had long been considered a dominant, and widely distributed species but epidemiological profiles of human Taenia species in Korea still remain unclear. In order to better understand distribution patterns of human Taenia tapeworms in Korea, partial nucleotide sequences of mitochondrial cox1 and ITS2 (internal transcribed spacer 2) were determined, along with morphological examinations, on 68 Taenia specimens obtained from university museum collections deposited since 1935. Genomic DNA was extracted from formalin-preserved specimens. Phylogenetic relationships among the genotypes (cox1 haplotype) detected in this study were inferred using the neighbor-joining method as a tree building method. Morphological and genetic analyses identified 3 specimens as T. solium, 51 specimens as T. asiatica, and 14 specimens as T. saginata. Our results indicate that all 3 ...

2008-12-20

187

Relationships of valve histology and mitochondrial and myofibril volume densities to hypertrophy of copper-deficient rat hearts  

Energy Technology Data Exchange (ETDEWEB)

Twenty-four male weanling rats were fed either copper-adequate or -deficient diets until 9 or 11 weeks of age. Deficient rat hearts had increased mitochondria: myofibril compared to adequate rats. Eleven week old deficient rat hearts had decreased mitochondria: myofibril as the hearts increased in weight, but the larger hearts had greater myofibril volume densities. Cardiac mitochondria of deficient rats appeared vacuolated with fragmented cristae and translucent matrix. Valves from copper deficient rats appeared to have less connective tissue and were fragmented in areas. For deficient rats, heart:body weights of 9 wk old rats were negatively correlated with bicuspid valve pathology scores, whereas tricuspid valve scores from 11 wk old rats were negatively correlated with myofibril volume densities. These data suggest that the enlargement of the copper-deficient rat heart is due to: larger (1) mitochondria and (2) myofibril volume densities.

1991-03-15

188

Morusin induces apoptosis and suppresses NF-#kappa#B activity in human colorectal cancer HT-29 cells  

International Nuclear Information System (INIS)

Morusin is a pure compound isolated from root bark of Morusaustralis (Moraceae). In this study, we demonstrated that morusin significantly inhibited the growth and clonogenicity of human colorectal cancer HT-29 cells. Apoptosis induced by morusin was characterized by accumulation of cells at the sub-G_1 phase, fragmentation of DNA, and condensation of chromatin. Morusin also inhibited the phosphorylation of IKK-#alpha#, IKK-#beta# and I#kappa#B-#alpha#, increased expression of I#kappa#B-#alpha#, and suppressed nuclear translocation of NF-#kappa#B and its DNA binding activity. Dephosphorylation of NF-#kappa#B upstream regulators PI3K, Akt and PDK1 was also displayed. In addition, activation of caspase-8, change of mitochondrial membrane potential, release of cytochrome c and Smac/DIABLO, and activation of caspase-9 and -3 were observed at the early time point. Downregulation in the expression of Ku70 and XIAP was exhibited afterward. Caspase-8 or wide-ranging ...

2008-07-18

189

Molecular characterization of cytoplasmic male sterility conditioned by Gossypium harknessii cytoplasm (CMS-D2) in upland cotton  

British Library Electronic Table of Contents (United Kingdom)

Cytoplasmic male sterility (CMS) is a maternally inherited trait that fails to produce functional pollen grains. The CMS system is widely employed to facilitate the utilization of heterosis in major crops. However, little is known about the CMS associated genes in Upland cotton (Gossypium hirsutum). The objective of this study was to compare CMS cotton (CMS-D2) with the cytoplasm from G. harknessii and its isogenic maintainer line with the normal fertile Upland cotton cytoplasm to identify CMS-D2 specific gene(s) and to develop CMS-specific sequence characterized amplified region (SCAR) markers. Based on Southern blot analysis using 10 mitochondrial gene-specific probes (cob, cox2, atp6, atp9, nad3, cox3, atpA, cox1, nad6 and nad9), three probes (cox3, atpA, and nad6) revealed restriction ...

2011-01-01

190

Evaluation of antioxidant and anti-atherogenic properties of Glycyrrhiza glabra root using in vitro models.  

Science.gov (United States)

The aim of present study was to evaluate antioxidant property of Glycyrrhiza glabra root extracts using in vitro models. The dose-dependent aqueous and ethanolic extracts demonstrated the scavenging activity against nitric oxide (concentration that caused 50% inhibition of nitric oxide radicals [IC(50)]=72 and 62.1 microg/ml, respectively), superoxide (IC(50)=64.2 and 38.4 microg/ml, respectively), hydroxyl (IC(50)=81.9 and 63 microg/ml, respectively), DPPH (IC(50)=43.6 and 28.3 microg/ml, respectively) and ABTS(*+) (IC(50)=77.3 and 57.2 microg/ml, respectively) radicals. Further, both extracts showed strong reducing power and iron-chelating capacities. In the Fe(2+)/ascorbate system, both extracts were found to inhibit mitochondrial fraction lipid peroxidation. In copper-catalyzed human serum and low-density lipoprotein oxidation models, both extracts significantly (P<0.05) lengthened the lag phase along with a decline in the oxidation rate, conjugated dienes, ...

2009-04-22

191

Understanding feline heartworm infection: disease, diagnosis, and treatment.  

Science.gov (United States)

Feline heartworm disease is a very different clinical entity from canine heartworm disease. In cats, the arrival and death of immature heartworms in the pulmonary arteries can cause coughing and dyspnea as early as 3 months postinfection. Adult heartworms suppress the function of pulmonary intravascular macrophages and thus reduce clinical disease in chronic feline heartworm infection. Approximately 80% of asymptomatic cats self-cure. Median survival time for symptomatic cats is 1.5 years, or 4 years if only cats living beyond the day of presentation are considered. Aberrant worm migration is more frequent than it is in dogs, and sudden death can occur with no prior clinical signs. The bacterial endosymbiont Wolbachia likely contributes to the inflammatory pathology of heartworm disease, but its role is not yet fully clear. Unfortunately, the diagnosis, treatment, and management of feline heartworm disease are far from simple. Antemortem diagnosis is hampered by ...

2010-11-01

192

Safety evaluation of Propionibacterium freudenreichii ET-3 culture.  

Science.gov (United States)

Propionibacterium freudenreichii ET-3 culture, a cell-free product of whey fermentation using P. freudenreichii ET-3 (7025), has been shown to promote the growth of Bifidobacteria through the action of 1,4-dihydroxy-2-naphthoic acid (DHNA), and therefore, has potential use in the food and supplement industries. Although currently used as a food ingredient in Japan, the safety of this novel ingredient has not been previously evaluated through traditional toxicity testing. Therefore, here we report the results of standard toxicological testing performed on P. freudenreichii ET-3 culture. In a 4-week oral toxicity study, administration of 6000mg/kg body weight/day P. freudenreichii ET-3 culture was without compound-related adverse effects on clinical signs, body weights, food consumption, ophthalmology, hematology, clinical chemistry, urinalysis, organ weights, and gross and microscopic findings in male and female Sprague-Dawley rats. Furthermore, in vitro mutagenicity testing ...

2011-03-22

193

Natural background radiation induces cytogenetic radioadaptive response more effectively than occupational exposure in human peripheral blood lymphocytes  

Science.gov (United States)

Ramsar, a city in the northern Iran, has the highest level of natural background radiation in the world. It has been clearly shown that low doses of ionising radiation can induce resistance to subsequent higher exposures. This phenomenon is termed radioadaptive response. We have compared induction of cytogenetic radioadaptive response by High Natural Background Radiation (HNBR) in Ramsar and X-ray occupational exposure as conditioning doses in human peripheral blood lymphocytes. 30 healthy control individuals, living in Ramsar but in normal background radiation areas, 15 healthy individuals from Talesh Mahalleh, a region with extraordinary high level of background radiation, and 7 X-ray radiographers working in Ramsar hospital located in normal natural background ionising radiation area were evaluated. Peripheral blood samples were prepared and exposed to challenge dose of 0 and 2 Gy. Lymphocytes were scored using analysis of metaphase, for the presence of chromosomal ...

2003-01-01

194

Nanofocusing refractive X-ray lenses  

Energy Technology Data Exchange (ETDEWEB)

This thesis is concerned with the optimization and development of the production of nanofocusing refractive X-ray lenses. These optics made of either silicon or diamond are well-suited for high resolution X-ray microscopy. The goal of this work is the design of a reproducible manufacturing process which allows the production of silicon lenses with high precision, high quality and high piece number. Furthermore a process for the production of diamond lenses is to be developed and established. In this work, the theoretical basics of X-rays and their interaction with matter are described. Especially, aspects of synchrotron radiation are emphasized. Important in X-ray microscopy are the different optics. The details, advantages and disadvantages, in particular those of refractive lenses are given. To achieve small X-ray beams well beyond the 100 nm range a small focal length is required. This is achieved in refractive lenses by moving to a compact lens design where several single lenses ...

2010-02-05

195

Identifying surface structural changes in layered Li-excess nickel manganese oxides in high voltage lithium ion batteries: A joint experimental and theoretical study  

Energy Technology Data Exchange (ETDEWEB)

High voltage cathode materials Li-excess layered oxide compounds Li[Ni{sub x}Li{sub 1/3-2x/3}Mn{sub 2/3-x/3}]O{sub 2} (0 < x < 1/2) are investigated in a joint study combining both computational and experimental methods. The bulk and surface structures of pristine and cycled samples of Li[Ni{sub 1/5}Li{sub 1/5}Mn{sub 3/5}]O{sub 2} are characterized by synchrotron X-Ray diffraction together with aberration corrected Scanning Transmission Electron Microscopy (a-S/TEM). Electron Energy Loss Spectroscopy (EELS) is carried out to investigate the surface changes of the samples before/after electrochemical cycling. Combining first principles computational investigation with our experimental observations, a detailed lithium de-intercalation mechanism is proposed for this family of Li-excess layered oxides. The most striking characteristics in these high voltage high energy density cathode materials are (1) formation of tetrahedral lithium ions at voltage less ...

2011-09-06

196

Gene rearrangement and radiation carcinogenesis  

International Nuclear Information System (INIS)

The development of leukemia and thyroid cancer is characterized by activation of the abl oncogene and ret oncogene, respectively. In order to clarify the relationship between these gene aberrations and radiation, the pro-myelogenous leukemia-derived cell line HL60 and the thyroid cancer-derived cell line 8505C, were irradiated in vitro with 100Gy of X-rays. RNA was then extracted from 10"8 cells of the respective cell lines and examined by the reverse transcription PCR method for rearrangements of abl and ret genes. Five kinds of positive bands were observed in the HL-60 cells irradiated with 100Gy of X-ray. Similarly, six positive bands were also observed in the 8505C cells irradiated with 100Gy. In vitro X-irradiation activation of oncogenes found in radiation induced cancers imply that gene rearrangement by X-rays is involved in the development of malignant tumors. Furthermore, in an experiment to detect radiation effects in A-bomb survivors, RNA was extracted ...

1993-11-01

197

Cytogenetic effects of protracted gamma exposures from conception of male mice  

Energy Technology Data Exchange (ETDEWEB)

In order to gain an overall picture of the genetic effects of an increased level of background radiation it is necessary to study the results of protracted exposures to embryonic and immature germ-cell stages as well as to stages found in the mature organism. For this purpose, litters produced by female mice, kept in a 10 or 20 rad/day /sup 60/Co ..gamma..-irradiation field, were kept in the same fields from conception until about 60 days later, having absorbed doses of 526 and 1078 rad respectively. Tests on exposed female offspring showed them to be sterile. Eight weeks after removal from the gamma field, mean testis masses of males in the 20 rad/day series were only half normal but those receiving 10 rad/day were little affected. Frequencies of translocations in spermatocytes at diakinesis/metaphase I were only slightly increased in the exposed series, differences not being significant. Estimated rates of translocation induction were around 5 x 10sup(-6) per rad, about one-third of ...

1982-01-01

198

A human breast cell model of pre-invasive to invasive transition  

Energy Technology Data Exchange (ETDEWEB)

A crucial step in human breast cancer progression is the acquisition of invasiveness. There is a distinct lack of human cell culture models to study the transition from pre-invasive to invasive phenotype as it may occur 'spontaneously' in vivo. To delineate molecular alterations important for this transition, we isolated human breast epithelial cell lines that showed partial loss of tissue polarity in three-dimensional reconstituted-basement membrane cultures. These cells remained non-invasive; however, unlike their non-malignant counterparts, they exhibited a high propensity to acquire invasiveness through basement membrane in culture. The genomic aberrations and gene expression profiles of the cells in this model showed a high degree of similarity to primary breast tumor profiles. The xenograft tumors formed by the cell lines in three different microenvironments in nude mice displayed metaplastic phenotypes, including squamous and basal ...

2008-03-10

199

On the impact of low power density microwaves in some living tissues  

Energy Technology Data Exchange (ETDEWEB)

The biomedical and ecological interest for the microwave impact on the Earth biosphere is continuously increased since the industrial, military and communication activities strongly contribute to the electromagnetic stress of living bodies. In the next the authors present some of the main results obtained regarding the microwave exposure of various types of biological material: bacteria, fungi, young plant seedlings, dry seeds, animal tissues. The electromagnetic exposure was carried out in open space in well controlled environmental conditions by using 10.75 GHz/1 m W cm{sup -2} microwaves. Biochemical assays and cytogenetic tests have been carried out to reveal the changes induced post irradiation. The response of some pathogen bacteria, have been emphasized by means of turbidimetric measurements - the stimulatory effect being noticed at the level of the microbial population density (the stimulation of the human body microbial flora seems to be one of the side effects of microwave ...

2006-07-01

200

Modulation of neuronal differentiation by CD40 isoforms  

International Nuclear Information System (INIS)

Neuron differentiation is a complex process involving various cell-cell interactions, and multiple signaling pathways. We showed previously that CD40 is expressed and functional on mouse and human neurons. In neurons, ligation of CD40 protects against serum withdrawal-induced injury and plays a role in survival and differentiation. CD40 deficient mice display neuron dysfunction, aberrant neuron morphologic changes, and associated gross brain abnormalities. Previous studies by Tone and colleagues suggested that five isoforms of CD40 exist with two predominant isoforms expressed in humans: signal-transducible CD40 type I and a C-terminal truncated, non-signal-transducible CD40 type II. We hypothesized that differential expression of CD40 isoform type I and type II in neurons may modulate neuron differentiation. Results show that adult wild-type, and CD40"-"/"- deficient mice predominantly express CD40 type I and II isoforms. Whereas adult wild-type mice express ...

2008-05-02

201

Unraveling photosystems. Final technical report  

Energy Technology Data Exchange (ETDEWEB)

This report highlights four main points. (1) A residue substitution in phosphoribulokinase of Synechocystis PCC 6803 renders the mutant light-sensitive. The authors isolated a light-sensitive mutant (BRLS) of the photosynthetic cyanobacterium Synechocystis 6803 that does not survive exposure to bright light; 70% of BRLS cells die upon exposure to light of > 3000 lux for 2 hr. (2) Excitation energy transfer from phycocyanin to chlorophyll in an apcA-defective mutant of Synechocystis sp. PCC 6803. A greenish mutant of the normally bule-green cyanobacterium Synechocystis sp. PC 6803, designated UV6p, was isolated and characterized. UV6p possesses functional photosystems I and II but lacks normal light harvesting phycobilisomes because allophycocyanin is absent and core-specific linker proteins are almost entirely absent. (3) Deletion of the psbG1 gene of the cyanobacterium Synechocystis sp. PCC 6803 leads to the activation of the cryptic psbG2 gene. The genes psbG1 and psbG2 in ...

1997-09-01

202

Thermal action of 2. 45 GHz microwaves on the cytoplasm of Chinese hamster cells  

Energy Technology Data Exchange (ETDEWEB)

In order to demonstrate possible specific effects of microwaves at the cellular level V-79 Chinese hamster cells were exposed to 2.45-GHz radiation at power levels of 20-200 mW/cm2 and at specific absorption rates of 10-100 mW/g. Intracellular cytoplasmic changes were observed by fluorescence polarization using a method based on the intracellular enzymatic hydrolysis of nonfluorescent fluorescein diacetate (FDA). At levels of absorbed energy below 90 J/g, modifications of microviscosity and mitochondrial state were absent, but a slight stimulation of enzymatic hydrolysis of FDA was observed which may be explained by microwave-induced alterations of cellular membranes possibly due to differences in heating pattern of microwaves compared to water-bath heating. At levels of absorbed energy above 90 J/g, the decrease of enzymatic hydrolysis of FDA, increase in degree of polarization, and increase of permeation of the fluorescent marker correlated well with the decrease ...

1984-01-01

203

The p75"N"T"R tumor suppressor induces cell cycle arrest facilitating caspase mediated apoptosis in prostate tumor cells  

International Nuclear Information System (INIS)

The p75 neurotrophin receptor (p75"N"T"R) is a death receptor which belongs to the tumor necrosis factor receptor super-family of membrane proteins. This study shows that p75"N"T"R retarded cell cycle progression by induced accumulation of cells in G0/G1 and a reduction in the S phase of the cell cycle. The rescue of tumor cells from cell cycle progression by a death domain deleted (#DELTA#DD) dominant-negative antagonist of p75"N"T"R showed that the death domain transduced anti-proliferative activity in a ligand-independent manner. Conversely, addition of NGF ligand rescued retardation of cell cycle progression with commensurate changes in components of the cyclin/cdk holoenzyme complex. In the absence of ligand, p75"N"T"R-dependent cell cycle arrest facilitated an increase in apoptotic nuclear fragmentation of the prostate cancer cells. Apoptosis of p75"N"T"R expressing cells occurred via the intrinsic mitochondrial pathway leading to a sequential caspase-9 and ...

2006-03-24

204

Sensitivity of mitochondrial K/sup +/ and Mg/sup + +/ influx rates to thiol reactive compounds  

Energy Technology Data Exchange (ETDEWEB)

Various thiol reactive compounds, including phenylarsine oxide (PheAsO) and mersalyl, activate K/sup +/ transport into respiring mitochondria. Dicyclohexylcarbodiimide (DCCD) inhibits K/sup +/ influx. In the present studies, unidirectional fluxes of K/sup +/ or Mg/sup + +/ into respiring rat liver mitochondria were measured by means of /sup 42/K or /sup 28/Mg, with samples separated from incubation media by centrifugation through silicon. Experiments show that the % stimulation of K/sup +/ influx by PheAsO (8.5 nmol/mg protein) or by mersalyl (150 ..mu..M) was the same (53-55%) for control mitochondria as for samples pretreated with DCCD (30 nmol/mg protein). This means that DCCD caused the same % inhibition of K/sup +/ flux into control mitochondria and mitochondria in the presence of PheAsO or mersalyl (36-37%). Thus, the DCCD reactive site associated with the K/sup +/ influx mechanism appears to be independent of the thiol groups(s) responsible for the observed activation. Earlier ...

1986-05-01

205

Patterns of lineage diversification in the genus Naso (Acanthuridae).  

Science.gov (United States)

The evolutionary history of the reef fish genus Naso (F. Acanthuridae) was examined using a complete species-level molecular phylogeny of all recognized (19) species based on three loci (one nuclear ETS2 and two mitochondrial 16S, cyt b). This study demonstrates that distinct foraging modes and specialized body shapes arose independently at different times in the evolutionary history of the genus. Members of the subgenus Axinurus, characterized by a scombriform morphology, caudal fin structure and pelagic foraging mode, were consistently placed basal to the remaining Naso species, suggesting that pelagic foraging is plesiomorphic and benthic foraging derived in this genus. We used a genus-level phylogeny (nuclear marker, ETS2), which included several taxa from all other acanthurid genera, to obtain a range of age estimates for the most recent common ancestor of the genus Naso. These age estimates (range of 52-43.3 MY) were then used to estimate divergence times (by ...

2004-07-01

206

Induction of biotransformation in the liver of Eel (Anguilla anguilla L. ) by sublethal exposure to dinitro-o-cresol: An ultrastructural and biochemical study  

Energy Technology Data Exchange (ETDEWEB)

Structural and functional alterations in hepatocytes of the European eel, Anguilla anguilla, following a 4-week-exposure to 5, 50, and 250 micrograms/liter dinitro-o-cresol (DNOC) were investigated by means of electron microscopy and biochemistry and compared to liver pathology in eels exposed to the chemical spill into the Rhine river at Basle in November 1986. Whereas phenological parameters (growth, condition factor) are unaffected, ultrastructural and biochemical alterations are detectable at greater than or equal to 50 and 5 micrograms/liter DNOC, respectively. Structural modifications include: rounding-up of the nuclei; fractionation and reduction of the rough endoplasmic reticulum; proliferation of the smooth endoplasmic reticulum (SER), mitochondria, peroxisomes, and lysosomes; bundles of rod-shaped SER profiles; annulate lamellae; membrane whorls within mitochondria; crystallization of the peroxisomal matrix and glycogen bodies; glycogen depletion and lipid augmentation. ...

1991-04-01

207

Glial inflammation and neurodegeneration induced by candoxin, a novel neurotoxin from Bungarus candidus venom: global gene expression analysis using microarray.  

Science.gov (United States)

Candoxin (PDB #1JGK), a three-finger neurotoxin from Bungarus candidus venom, inhibits post-synaptic neuromuscular and neuronal alpha7nACh-receptors, and induces delayed cell-death throughout the glial population. When applied to cultured human glial cell lines, candoxin (CDX) induced cell death in a concentration (EC(50) approximately 1muM) and time dependent manner. Results of TUNEL-histochemistry further confirm CDX-induced brain (hippocampus, frontal cortex, and temporal regions) damage when administered intracerebroventricularly (i.c.v) in adult mice. In this study, we explored differential gene expression profiles following exposure of human glial (Hs 683) cell lines to CDX at various time intervals using Affymetrix-GeneChips. By means of MAS and GeneSpring analyses, 105 genes whose expression was significantly (P<0.01) altered by at least 3-fold were selected. Results of the genome analysis reveal that the potential role of CDX at molecular level involves the regulation of ...

2005-11-23

208

Fossil avian eggshell preserves ancient DNA  

DEFF Research Database (Denmark)

Owing to exceptional biomolecule preservation, fossil avian eggshell has been used extensively in geochronology and palaeodietary studies. Here, we show, to our knowledge, for the first time that fossil eggshell is a previously unrecognized source of ancient DNA (aDNA). We describe the successful isolation and amplification of DNA from fossil eggshell up to 19 ka old. aDNA was successfully characterized from eggshell obtained from New Zealand (extinct moa and ducks), Madagascar (extinct elephant birds) and Australia (emu and owl). Our data demonstrate excellent preservation of the nucleic acids, evidenced by retrieval of both mitochondrial and nuclear DNA from many of the samples. Using confocal microscopy and quantitative PCR, this study critically evaluates approaches to maximize DNA recovery from powdered eggshell. Our quantitative PCR experiments also demonstrate that moa eggshell has approximately 125 times lower bacterial load than bone, making it a highly ...

2010-01-01

209

Effects of. gamma. -irradiation on isolated rat liver mitochondria  

Energy Technology Data Exchange (ETDEWEB)

Gamma-irradiation of isolated rat liver mitochondria with up to 475 Gy leading to hydrated electrons (G = 1.9, corrected for reaction with solutes), 30 Gy leading to carbohydrate radicals, (G = 5.6), 100 Gy leading to superoxide radicals (G = 6.2), and 130 Gy leading to formate radicals (G = 6.2) showed no effects on the rate of oxygen uptake in various respiratory states, the respiratory control ratio, or the adenosine diphosphate to atomic oxygen ratio. Typical values were 0.020-0.100 nmol O/sub 2/ s/sup -1/ mg protein/sup -1/ for State 1 respiration, 0.25-0.33 nmol O/sub 2/ s/sup -1/ mg protein/sup -1/ for State 4 respiration and 0.65-1.10 nmol O/sub 2/ s/sup -1/ mg protein/sup -1/ for State 3 respiration. Typical respiratory control ratios ranged from 2.0-3.5 for succinate and 4.0-6.5 for a 1:1 glutamate: malate substrate mixture. Adenosine diphosphate to atomic oxygen ratios with succinate as substrate varied from 1.6 to 1.9. In situ and in vitro irradiated mitochondria were ...

1987-01-01

210

Dispersion of Metals from Abandoned Mines and their Effect on Biota in the Methow River, Okanogan County, Washington: Final Report 2002-2003.  

Energy Technology Data Exchange (ETDEWEB)

A study of mine-waste contamination effects on Methow River habitat on the eastern slopes of the north Cascade Mountains in Washington state, U.S.A., revealed impacts at ecosystem, community, population, individual, tissue, and cellular levels. Ore deposits in the area were mined for gold, silver, copper and zinc until the early 1950's, but the mines are now inactive. An above-and-below-mine approach was used to compare potentially impacted to control sites. The concentrations of eleven trace elements (i.e., Al, As, B, Ba, Cd, Cr, Cu, Mn, Pb, Se, and Zn) in Methow River sediments downstream from the abandoned mine sites were higher than background levels. Exposed trout and caddisfly larvae in the Methow River showed reduced growth compared to controls. Samples of liver from juvenile trout and small intestine from exposed caddisfly larvae were examined for evidence of metal accumulation, cytopathological change, and chemical toxicity. Morphological changes that are ...

2003-05-15

211

Characterization of the major phosphoprotein and its kinase on the surface of the rat adipocyte  

Energy Technology Data Exchange (ETDEWEB)

Intact rat fat cell exposed to 12.5 ..mu..M (..gamma..-32P)ATP incorporate label into specific proteins within minutes. By solubilizing the reaction mixture with SDS which bypasses the subcellular fractionation steps, the labeled proteins can be identified in autoradiographs of SDS-PAGE gels. The most prominently labeled protein has an M/sub r/ of 42,000. Localization of this component to the cell surface can be made on the basis of inhibition of phosphorylation by addition of a protein derived from the rat brain with protein kinase inhibitory property, susceptibility of the phosphorylated protein to the tryptic digestion, inhibition of phosphorylation of this protein after brief exposure to melittin. To rule out the possibility that the cell surface protein might be a mitochondrial contaminant from broken cells, /sup 32/Pi-labeled and (..gamma..-/sup 32/P)ATP-labeled cells were chromatographed on a rabbit anti-pyruvate dehydrogenase antibody-Sepharose 4B column. A ...

1986-12-01