bluuebunny/crossref_metadata_2025 huggingface dataset:
Expression of luciferase and β-glucuronidase in Pinusradiata suspension cells using electroporation and particle bombardment
Authors: Campbell M.A. , Kinlaw C.S. , Neale D.B.
Published: October 2009

The reporter gene β-glucuronidase, under the control of the 35S promoter from cauliflower mosaic virus, was introduced into a suspension-cultured cell line of Pinusradiata using electroporation and particle bombardment. Electroporation of suspension-derived protoplasts in the presence of pBI221 resulted in transient β-glucuronidase activity. Maximum levels of β-glucuronidase activity were obtained 24 h after electroporation using field strengths of 1000 V/cm but decreased to background levels within 48 h. This decrease corresponded to a drop in protoplast viability and metabolic activity, as determined by fluorescein diacetate staining and chlorophyll fluorescence. Electroporation of P. radiata protoplasts with a plasmid containing a firefly luciferase reporter gene driven by a 35S promoter resulted in expression levels that were 2–3.5 times that of background. Biolistic transfer of a β-glucuronidase coding sequence driven by a 35S promoter resulted in histochemically detectable β-glucuronidase activity in P. radiata suspension culture cells. Extracts from P. radiata suspension culture cells containing 800 μg soluble protein inhibited the β-glucuronidase activity of Escherichiacoli extracts by 50%. Aliquots of P. radiata extracts containing less than 100 μg of total soluble protein did not exhibit any inhibitory effect. These studies establish two different methods of gene transfer into a P. radiata cell line and will contribute to our ability to examine a variety of promoter types associated with transcriptional regulation in conifers.
FIRST-PRINCIPLES STUDY OF ELECTRONIC STRUCTURE AND GROUND-STATE PROPERTIES OF ALKALI-METAL SELENIDES AND TELLURIDES (M2A)[M: Li, Na, K; A: Se, Te]
Authors: EITHIRAJ R. D. , JAIGANESH G. , KALPANA G.
Published: October 2009

First-principles calculations have been performed to investigate the electronic structure and ground-state properties of alkali-metal Selenides (M2Se) and Tellurides (M2Te) [ M: Li, Na, K ] using the Tight-Binding Linear Muffin-Tin Orbital (TB-LMTO) method. The exchange correlation energy is described within the local density approximation (LDA) using the von Barth and Hedin parameterization scheme. At ambient conditions, these compounds are found to crystallize in the face center cubic antifluorite (anti- CaF 2-type) structure. Ground-state properties such as total energy, equilibrium lattice parameter, and bulk modulus are calculated for these compounds. The calculated equilibrium lattice parameter is in agreement with experimental result. From the electronic structure calculations, we find that Li 2 Se , Li 2 Te , K 2 Se , and K 2 Te are indirect bandgap semiconductors, whereas Na 2 Se and Na 2 Te are direct bandgap semiconductors. The present results are compared with the earlier results of series of alkali-metal sulfides (M2S) and alkali-metal oxides ( M 2 O ), allowing us to make predictions about the total energy, bulk modulus, valence-band width, and bandgap behavior of the rest of the alkali-chalcogenide crystals.
ELECTRONIC TRANSPORT IN RANDOM DIMER/TRIMER GaAs/AlxGa1-xAs SUPERLATTICES
Authors: DJELTI R. , BENTATA S. , AZIZ Z.
Published: October 2009

By using a transfer matrix model, we examined in this paper the extended states of a noninteracting electron in one-dimensional dimer/trimer randomly placed in superlattices (SLs). We study numerically the effects of short-range correlated disorder on the electronic transport properties and intentionally disordered GaAs/Al x Ga 1-x As SLs. We consider layers having identical thickness where the Al concentration x takes at random two different values with the constraint that one of them appears only in pairs or triply i.e., the random dimer/trimer barrier.
STUDY OF Y1-xCaxBa2-yLayCu3Oz CARRIER UN-COMPENSATING SYSTEM
Authors: JIN W. T. , HAO S. J. , ZHANG H. , ZHAO Y.
Published: October 2009

The single-phase samples of Y 0.9 Ca 0.1 Ba 2-y La y Cu 3 O z and Y1-x Ca x Ba 1.5 La 0.5 Cu 3 O z were synthesized with both x and y from 0 to 0.5, respectively. Structural and superconducting properties have been investigated by X-ray diffraction, Rietveld refinement, and DC magnetization measurement, respectively. Different from the self-compensating compound of Y 1-x Ca x Ba 2-x La x Cu 3 O z, carriers in these two systems of Y1-x Ca x Ba 2-y La y Cu 3 O z are not compensated as x ≠ y. By careful study of the chemical bond lengths related to Cu (2)– O plane and Cu (1)– O chain, it is demonstrated that the critical temperature (Tc) changes monotonously with the bond lengths of Cu (1)– O (4) and Cu (2)– O (4). The analysis demonstrates that crystalline structure is one of the important factors to high-Tc superconductivity, and its influence is independent of the carrier concentration.
Geochronological constraints on the evolution of the southern Dom Feliciano Belt (Uruguay)
Authors: Oyhantçabal Pedro , Siegesmund Siegfried , Wemmer Klaus , Presnyakov Sergey , Layer Paul
Published: October 2009

New U–Pb sensitive high-resolution ion microprobe, K–Ar and Ar–Ar data from the southernmost Dom Feliciano Belt allow the identification of four major events. Orthogneisses from the Punta del Este Terrane indicate a magmatic episode at
c
. 770 Ma and high-grade metamorphism at 641 ± 17 Ma. Granitoid emplacement at 627 ± 23 Ma was roughly coeval with peak metamorphism. Volcaniclastic rocks of the Las Ventanas Formation dated at 573 ± 11 Ma can be correlated with the peripheral foreland basin (571 ± 8 Ma). Transpression and coeval high-K calc-alkaline magmatism is recorded in the Maldonado granite dated at 564 ± 7 Ma. The following events are postulated: (1) magmatism at 850–750 Ma related to rifting; (2) metamorphism and granite emplacement at 650–600 Ma; (3) molasse sequences and foreland basins at
c
. 573 Ma; (4) late magmatism at 580–560 Ma associated with transpression. The data indicate that (1) the Punta del Este Terrane could be a portion of the Coastal Terrane of the Kaoko Belt, (2) granitoid emplacement at 650–600 Ma in the Punta del Este and Nico Pérez terranes favours westward subduction, and (3) widespread post-collisional synkinematic magmatism occurred in the Dom Feliciano and Kaoko belts between 580 and 550 Ma.

Supplementary material:

Analytical methods and data are available at
http://www.geolsoc.org.uk/SUP18369
.
High spatial resolution
40
Ar/
39
Ar dating of pseudotachylites: geochronological evidence for multiple phases of faulting within basement gneisses of the Outer Hebrides (UK)
Authors: Sherlock Sarah C. , Strachan Rob A. , Jones Kevin A.
Published: October 2009

Pseudotachylites within the Neoarchaean to Palaeoproterozoic basement of the Lewisian Gneiss Complex have been analysed using the high spatial resolution
40
Ar/
39
Ar UV laserprobe technique. It has been possible to measure
40
Ar/
39
Ar age and ‘apparent' age variations that would be beyond resolution by lower spatial resolution or bulk
40
Ar/
39
Ar dating methods. We report a range of complexities including significantly younger narrow (<1 mm) margins on much older pseudotachylite veins, and heterogeneous excess argon contamination. We also report pseudotachylite veins of varying magnitudes that have been subject to later thermal reheating, whereby there is a relationship between vein thickness and extent of argon loss. In spite of these it is still possible to determine geologically meaningful
40
Ar/
39
Ar ages for pseudotachylite-forming events. In Lewis the
c
. 1900 Ma event may relate to early stages of Laxfordian reworking. In Barra and South Uist a 1300–1200 Ma event is recorded, whereas in Barra, South and North Uist a second event is recorded at
c
. 700 Ma, which is likely to be associated with NW- and west-directed thrusting, and could represent far-field effects of tectonic events recorded at this time east of the Moine Thrust in NW Scotland.

Supplementary material:

40
Ar/
39
Ar data are available at
http://www.geolsoc.org.uk/SUP18372
.
First report of amber with spider webs and microbial inclusions from the earliest Cretaceous (
c
. 140 Ma) of Hastings, Sussex
Authors: BRASIER MARTIN , COTTON LAURA , YENNEY IAN
Published: October 2009

Early Cretaceous amber resins with macroscopic inclusions are extremely rare, as are ambers with inclusions from the parent plant. Here, we report earliest Cretaceous amber resins found within alluvial soils of the Ashdown Formation near Hastings in Sussex. In contrast to younger Cretaceous examples, this Hastings amber was arguably deposited shortly before the emergence of the earliest flowering plant communities
c
. 140 Ma BP. Preliminary studies reveal plentiful organic inclusions, including vascular tissues, tracheid cells and putative resin ducts of the parent coniferous trees. We also report remarkably preserved soil microbes, including structures comparable with actinobacterial colonies, putative fungal or cyanobacterial filaments, and the earliest examples of spider silk webs. The last includes threads that are twisted, paired and coated with sticky fluid droplets, comparable with those of araneoid spider webs studied by us in modern cherry tree resins. Together, these Hastings amber inclusions became entombed within resins that seeped through the charred bark of coniferous trees subjected to severe fire damage, whose logs were then swept onto fluvial wetlands by floods. Embalming resins of this kind may have evolved to combat damage associated with insects, fungi and widespread forest fires.
Evidence for 930 Ma metamorphism in the Shetland Islands, Scottish Caledonides: implications for Neoproterozoic tectonics in the Laurentia–Baltica sector of Rodinia
Authors: CUTTS K.A. , HAND M. , KELSEY D.E. , WADE B. , STRACHAN R.A. , CLARK C. , NETTING A.
Published: October 2009

Zircon and monazite laser-ablation inductively coupled plasma mass spectrometry U–Pb geochronological data for two metasediment samples from the Westing Group, northern Shetland Islands, Scottish Caledonides yield ages between 938 ± 8 and 925 ± 10 Ma (Tonian) for upper amphibolites-facies metamorphism. Texturally early metamorphism is recorded by a migmatitic garnet + sillimanite + plagioclase + muscovite + biotite assemblage, which formed at
c
. 650–700 °C and 7 kbar. Subsequent reworking resulted in the growth of a secondary garnet + kyanite + plagioclase + muscovite + biotite assemblage at
c
. 650 °C and 8–9 kbar.
In situ
electron probe microanalysis (EPMA) U–Th–Pb chemical dating of monazite hosted within garnet grains and the matrix of one sample also give Tonian ages, apparently indicating that all the metamorphism occurred during the Neoproterozoic. However, the dominant structural fabrics appear to have formed during the Ordovician–Silurian Caledonian orogeny, suggesting that the reworking was substantially younger despite the apparent absence of Caledonian monazite or zircon ages. Detrital zircons are consistent with Laurentia–Baltica provenance. Deposition of the Westing Group is constrained to between
c
. 1030 and 930 Ma. The timing of Tonian metamorphism suggests possible correlations with sequences elsewhere in the northern Caledonides, including the Krummedal Succession of East Greenland and Laurentian-derived successions in Svalbard and northern Norway.

Supplementary material:

U–Pb LA-ICPMS and EPMA data are available at
http://www.geolsoc.org/SUP18379
.
Tectonomagmatic events during stretching and basin formation in the Labrador Sea and the Davis Strait: evidence from age and composition of Mesozoic to Palaeogene dyke swarms in West Greenland
Authors: LARSEN LOTTE M. , HEAMAN LARRY M. , CREASER ROBERT A. , DUNCAN ROBERT A. , FREI ROBERT , HUTCHISON MARK
Published: October 2009

Mesozoic to Palaeogene intrusive igneous rocks in West Greenland range from a large, coast-parallel dyke swarm to small, poorly defined dyke swarms or single intrusions. New age and geochemical data indicate that intrusion forms and melt compositions changed with time, dependent on changing stress fields and increasing lithospheric attenuation. During the periodc. 220–150 Ma (Late Triassic to Late Jurassic) incipient stretching is reflected in the production of highly alkaline, volatile-rich melts formed in small volumes in the deep lithosphere. Around 150 Ma (Kimmeridgian), increased extension took place and melts were intruded in a 60 km long swarm of scattered alkaline dykes. In the Early Cretaceous, 140–133 Ma, the regional stress field was intense, upwelling asthenospheric mantle started to melt, and alkali basaltic magmas were emplaced in a 400 km long coastal dyke swarm parallel to large linear faults offshore. In the Palaeocene, continental break-up took place and flood basalts (62–60 Ma) were extruded in the Nuussuaq Basin. Large basalt sills and dykes extend the region with Palaeocene activity 150 km southwards and form a link between the Nuussuaq Basin and the Sisimiut Basin offshore. Dykes with ages of 57–51 Ma indicate widespread younger volcanic activity.

Supplementary material:

Sample details, Ar/Ar data and plots, and Rb–Sr isochrons are available athttp://www.geolsoc.org.uk/SUP18374.
Field-based investigations of an ‘Infracambrian’ clastic succession in SE Libya and its bearing on the evolution of the Al Kufrah Basin
Authors: Le Heron Daniel Paul , Howard James P. , Alhassi Aiyad Mohamed , Anderson Lester , Morton Andrew , Fanning C. Mark
Published: October 2009

Field-based investigation of ‘Infracambrian’ rocks cropping out on the eastern flank of Al Kufrah Basin (area 500 000 km
2
) reveals a an approximately 500 m-thick clastic succession of massive and cross-bedded sandstones, separated by 60 m-thick mudrock intervals. New zircon age data indicate a maximum age of deposition of approximately 950 Ma; furthermore, the absence of zircons of Pan-African age suggests a minimum depositional age older than the Pan-African Orogeny. Previously unreported folding and spaced cleavage affects these deposits to produce a pronounced NE–SW-striking tectonic grain that is interpreted to result from NW–SE-directed orthogonal compression during the Pan-African Orogeny. These Infracambrian rocks are therefore unlikely to be suitable analogues for weakly deformed strata shown to exist beneath the Cambro-Ordovician strata of the Al Kufrah Basin. Earlier work mapped a series of Infracambrian marble outcrops along strike of the clastic deposits; thin section petrography reveals that some of these are basic igneous rocks metamorphosed to greenschist facies. Interpretation of gravity data over the Al Kufrah Basin shows NE–SW-striking faults, parallel to outcrop structures, and secondary NW–SE faults. The data do not support earlier interpretations of a rhomboidal geometry in the deep subsurface of the basin, which has previously been attributed to strike-slip (pull-apart) processes. This research impacts on earlier suggestions that the Al Kufrah Basin opened as one of a series of en echelon pull-apart basins situated along a 6000 km-long shear zone known as the Transafrican Lineament, stretching from the Nile to the Niger Delta.
Upper Vendian-lowest Ordovician sequences of the western Gondwana margin, NE Spain
Authors: Vintaned José A. Gámez , Schmitz Ulrich , Liñán Eladio
Published: October 2009

The intra-Vendian (Ediacaran)–intra-Tremadocian succession of the Cadenas Ibéricas in NE Spain is divided into nine sequences. Overall, these are interpreted as second-order sequences. Those that encompass Lower and lower Middle Cambrian carbonates, with identified transgressive systems tract (TST) and highstand systems tract (HST) phases, may constitute elements of composite sequences. The lowermost sequence is of Late Vendian age. In Lower and lower Middle Cambrian units, sequence tops indicate drowning, reflecting extensional tectonics. Rifting effects are traceable up to mid-Mid Cambrian times. The remaining sequences probably represent a sag phase, either accentuating the preceding extensional local basin regime or heralding the Gondwana passive margin stage. Of the southerly Gondwana deposits those of other areas of the Iberian Peninsula and of the Moroccan Anti-Atlas fold belt show similar conditions during the Early Cambrian, that is, an Early Cambrian extensional regime, and, as for the Moroccan fold belt, four sequences imaging TST and HST phases.
The 'Infracambrian System' in the southwestern margin of Gondwana, southern South America
Authors: Hlebszevitsch J. C. , Gebhard I. , Cruz C. E. , Consoli V.
Published: October 2009

The classical definition of ‘Infracambrian’ that refers strictly to sequences of Proterozoic age is not applicable in southwestern Gondwana. In this paper the term ‘Infracambrian’ is used to define the sequences deposited during the Pampean orogenic cycle, which extends until the Cambrian period.

A classification of Infracambrian basins is proposed based on location, level of preservation and perceived petroleum potential. Only the eastern basins of the South American plate have potentially significant exploration potential.

Two Neoproterozoic petroleum systems have been identified in the eastern basins: a Riphean system, developed on the western margin of the San Francisco Craton, in the San Francisco Basin of Brazil; and a Vendian system, developed on the eastern margin of the Amazonia–Río de la Plata cratons, in the Corumbá Basin of Brazil and Paraguay. The Riphean system is reportedly proven by a well test drilled by Petrobras. An active Vendian petroleum system is proven by the presence of oil seeps within fractured limestones. A Vendian petroleum system is proposed for the Claromecó Basin of Argentina based on the correlation of the Vendian and Riphean sequences.
Macroevolutionary turnover through the Ediacaran transition: ecological and biogeochemical implications
Authors: Butterfield Nicholas J.
Published: October 2009

Ecological and evolutionary principles are often context-dependent, particularly where the context is biologically defined. Organ-grade animals (eumetazoans) are particularly powerful contextual agents, with a unique capacity to drive escalatory co-evolution and build multi-tiered food-webs. The evolution of eumetazoans through the Ediacaran and early Cambrian fundamentally altered macroecological and macroevolutionary dynamics, including the structure and function of the marine carbon cycle. Pelagic eumetazoans can be held responsible for driving the evolution of relatively large eukaryotic phytoplankton, thereby shifting the system from a turbid, stratified, cyanobacteria-dominated stable state to the clear-water, well-oxygenated, algae-dominated condition typical of the Phanerozoic. Intermittent return to the pre-Ediacaran state during Phanerozoic extinctions and oceanic anoxic events suggests that the widespread anoxia detected in pre-Ediacaran deep-marine sequences may be a consequence of this alternate biological pump rather than a reflection of fundamentally lower levels of atmospheric oxygen. The transition between the pre- and post-Ediacaran states is also associated with the oldest commercially exploitable hydrocarbons, a possible by-product of invading animals and their top-down impact on the biological pump.
Infracambrian sediments in Libyan sedimentary basins
Authors: Benshati H. , Khoja A. , Sola M.
Published: October 2009

Infracambrian sediments are widely distributed in Libya, outcropping on the eastern and western margins of Al Kufrah Basin and the eastern margin of Murzuq Basin. The sediments have been penetrated in the Central Cyrenaica Platform, Concession 10, NW Sirte Basin, and Block NC115, NW Murzuq Basin.

There are two main subdivisions. The first is metamorphosed due to local volcanism in the Murzuq and Al Kufrah basins. The second is unaltered and has been penetrated in the NW Sirte Basin. It occurs as outcropping limestone on the eastern margin of the Murzuq Basin.

These sediments generally show lateral thickness variability, with the thickest section, approximately 991–1067 m, in the Cyrenaica Platform. Individual units show thinning towards the Precambrian basement highs, and both fining-up and coarsening-up successions. Two-dimensional seismic data acquired by the operating companies AGIP and AGOCO in the southern Al Kufrah Basin image strata presumed to be Infracambrian.

The Infracambrian sediments were probably deposited as lens-shaped bodies in palaeo-lows (graben, half-graben and troughs) alongside Precambrian basement highs, trending NW–SE in the Cyrenaica platform and NE–SW in the Al Kufrah and Murzuq basins. These sediments show lateral facies changes and their nomenclature differs across the basins. Palynological and palaeontological studies suggest a Late Riphean age.
The effect of different patterns of growth hormone administration on the IGF axis and somatic and skeletal growth of the dwarf rat
Authors: Westwood Melissa , Maqsood Arfa R. , Solomon Mattea , Whatmore Andrew J. , Davis Julian R. E. , Baxter Robert C. , Gevers Evelien F. , Robinson Iain C. A. F. , Clayton Peter E.
Published: October 2009

Normal childhood growth is determined by ultradian and infradian variations in GH secretion, yet GH treatment of children with short stature is restricted to daily fixed doses. We have used GH-deficient dwarf rats to determine whether variable GH dose regimens promote growth more effectively than fixed doses. Animals were treated with saline or 4.2 mg of recombinant bovine GH given as 1) 700 μg/wk in 100 μg/day doses, 2) alternating weekly doses of 966 (138 μg/day) or 434 μg (62 μg/day), or 3) 700 μg/wk in randomized daily doses (5–250 μg/day). Body weight and length were measured weekly. Femur and tibia lengths and internal organ, fat pad, and muscle weights were recorded at the end of the study (6 wk); blood was collected for IGF axis measurements. GH promoted femur [ F(3,60) = 14.67, P < 0.05], tibia [ F(3,60) = 14.90, P < 0.05], muscle [ F(3,60) = 10.37, P < 0.05], and organ growth [liver: F(3,60) = 9.30, P < 0.05; kidney: F(3,60) = 2.82, P < 0.05] and an increase in serum IGF-I [ F(3,60) = 9.18, P < 0.05] and IGFBP-3 [ F(3,60) = 6.70, P < 0.05] levels. IGF-I levels correlated with final weight ( r = 0.45, P < 0.05) and length ( r = 0.284, P < 0.05) in the whole cohort, but within each group, growth parameters correlated with serum IGF-I only in animals treated with random GH doses. The variable regimens promoted femur length ( P < 0.05) and muscle ( P < 0.05) and kidney ( P < 0.05) weight more effectively than treatment with the fixed regimen. This study demonstrates that aspects of growth are improved following introduction of infradian variation to GH treatment in a GH-deficient model. The data suggest that varying the pattern of GH doses administered to children may enhance growth performance without increasing the overall GH dose.
Alterations in oxidative gene expression in equine skeletal muscle following exercise and training
Authors: Eivers Suzanne S. , McGivney Beatrice A. , Fonseca Rita G. , MacHugh David E. , Menson Katie , Park Stephen D. , Rivero Jose-Luis L. , Taylor Cormac T. , Katz Lisa M. , Hill Emmeline W.
Published: October 2009

Intense selection for elite racing performance in the Thoroughbred horse ( Equus caballus) has resulted in a number of adaptive physiological phenotypes relevant to exercise; however, the underlying molecular mechanisms responsible for these characteristics are not well understood. Adaptive changes in mRNA expression in equine skeletal muscle were investigated by real-time qRT-PCR for a panel of candidate exercise-response genes following a standardized incremental-step treadmill exercise test in eight untrained Thoroughbred horses. Biopsy samples were obtained from the gluteus medius before, immediately after, and 4 h after exercise. Significant ( P < 0.05) differences in gene expression were detected for six genes ( CKM, COX4I1, COX4I2, PDK4, PPARGC1A, and SLC2A4) 4 h after exercise. Investigation of relationships between mRNA and velocity at maximum heart rate (VHRmax) and peak postexercise plasma lactate concentration ([La]T1) revealed significant ( P < 0.05) associations with postexercise COX4I1 and PPARCG1A expression and between [La]T1and basal COX4I1 expression. Gene expression changes were investigated in a second cohort of horses after a 10 mo period of training. In resting samples, COX4I1 gene expression had significantly increased following training, and, after exercise, significant differences were identified for COX4I2, PDK4, and PPARGC1A. Significant relationships with VHRmaxand [La]T1were detected for PPARGC1A and COX4I1. These data highlight the roles of genes responsible for the regulation of oxygen-dependent metabolism, glucose metabolism, and fatty acid utilization in equine skeletal muscle adaptation to exercise.
Identification and characterization of a novel ABCA3 mutation
Authors: Park Sang-Kyu , Amos Louella , Rao Aparna , Quasney Michael W. , Matsumura Yoshihiro , Inagaki Nobuya , Dahmer Mary K.
Published: October 2009

Mutations in the gene coding for ATP-binding cassette protein A3 (ABCA3) are recognized as a genetic cause of lung disease of varying severity. Characterization of a number of mutant ABCA3 proteins has demonstrated that the mutations generally affect intracellular localization or the ability of the protein to hydrolyze ATP. A novel heterozygous mutation that results in the substitution of cysteine for arginine at amino acid 295 in ABCA3 was identified in a premature infant with chronic respiratory insufficiency and abnormal lamellar bodies. Sequencing of DNA performed in study participants demonstrated that this was a mutation and not a common variant. Plasmid vectors containing ABCA3 with the identified novel mutation tagged with green fluorescent protein on the carboxy terminus were generated. The effect of the mutation on protein function was characterized by examining the glycosylation state of the mutant protein in transiently transfected HEK293 cells and by examining ATP hydrolysis activity of the mutant protein with a vanadate-induced nucleotide trapping assay in stably transfected HEK293 cells. The ABCA3 protein containing the R295C mutation undergoes normal glycosylation and intracellular localization but has dramatically reduced ATP hydrolysis activity (12% of wild type). The identification of one copy of this novel mutation in a premature infant with chronic respiratory insufficiency suggests that ABCA3 haploinsufficiency together with lung prematurity may result in more severe, or more prolonged, respiratory failure.
Retinoblastoma and the Genetic Theory of Cancer: An Old Paradigm Trying to Survive to the Evidence
Authors: Mastrangelo Domenico , Hadjistilianou Theodora , De Francesco Sonia , Loré Cosimo
Published: October 2009

Retinoblastoma (Rb) is considered to represent the prototype of cancer linked to the sequential loss or inactivation of both alleles of a so-called “tumor suppressor gene”, the Rb1 gene. The pathogenetic mechanism behind this tumor was first hypothesized by Knudson in 1971 and further confirmed by others who identified the Rb1 gene whose loss or inactivation was claimed to be responsible for the disease. However, after about four decades of continuous research in the field of molecular biology, the evidence behind the role of the Rb1 gene in Rb appears to be seriously flawed in the light of epidemiological, biological, and clinical evidences. This editorial summarizes the inconsistencies on this subject. Nevertheless, the molecular biology establishment still adheres to the biased view of the genetic origin of Rb and other cancers, and hardly any alternative explanations are taken into account.
Existence of Solutions for a Nonlinear Algebraic System
Authors: Zhang Guang , Bai Liang
Published: October 2009

As well known, the existence and nonexistence of solutions for nonlinear
algebraic systems are very important since they can provide the necessary
information on limiting behaviors of many dynamic systems, such as the
discrete reaction‐diffusion equations, the coupled map lattices, the
compartmental systems, the strongly damped lattice systems, the complex
dynamical networks, the discrete‐time recurrent neural networks, and the
discrete Turing models. In this paper, both the existence of nonzero
solution pairs and the nonexistence of nontrivial or nonzero solutions for
a nonlinear algebraic system will be considered by using the critical point
theory and Lusternik‐Schnirelmann category theory. The process of proofs on
the obtained results is simple, the conditions of theorems are also easy to
be verified, however, some of them improve the known ones even if the system
is reduced to the precial cases, in particular, others of them are still
new.
Asthma in the Elderly
Authors: Urso Domenico Lorenzo
Published: October 2009

Bronchial asthma is a common problem with enormous medical and economics impacts. It is an inflammatory disease of the airways associated with intermittent episodes of bronchospasm. Asthma is not uncommon in the elderly patients. Prevalence of asthma is similar in older and younger adults. Asthma in the elderly patient is underdiagnosed because of false perceptions by both patient and physician. The high incidence of comorbid conditions in the elderly patient makes the diagnosis and management more difficult. Correct diagnosis is demonstrated with spirometry. The goals of asthma treatment are to achieve and maintain control of symptoms and to prevent development of irreversible airflow limitation. Asthma drugs are preferably inhaled because this route minimizes systemic absorption and, thus, improves the ratio of the therapeutic benefit to the potential side-effects in elderly patients.
The BRAFV600E Oncogene Induces Transforming Growth Factor β Secretion Leading to Sodium Iodide Symporter Repression and Increased Malignancy in Thyroid Cancer
Authors: Riesco-Eizaguirre Garcilaso , Rodríguez Irene , De la Vieja Antonio , Costamagna Eugenia , Carrasco Nancy , Nistal Manuel , Santisteban Pilar
Published: October 2009

The activating mutation BRAFV600E is a frequent genetic event in papillary thyroid carcinomas (PTC) that predicts a poor prognosis, leading to loss of sodium/iodide symporter (NIS) expression and subsequent radioiodide-refractory metastatic disease. The molecular basis of such an aggressive behavior induced by BRAF remains unclear. Here, we show a mechanism through which BRAF induces NIS repression and promotes epithelial to mesenchimal transition and invasion based on the operation of an autocrine transforming growth factor (TGF)β loop. BRAF induces secretion of functional TGFβ and blocking TGFβ/Smad signaling at multiple levels rescues BRAF-induced NIS repression. Although this mechanism is MAP/extracellular signal-regulated kinase (ERK) kinase (MEK)-ERK independent, secreted TGFβ cooperates with MEK-ERK signaling in BRAF-induced cell migration, Matrigel invasion, and EMT. Consistent with this process, TGFβ and other key components of TGFβ signaling, such as TβRII and pSmad2, are overexpressed in human PTC, suggesting a widespread activation of this pathway by locally released TGFβ. Moreover, this high TGFβ/Smad activity is associated with PTC invasion, nodal metastasis, and BRAF status. Interestingly, TGFβ is overexpressed in the invasive front, whereas NIS is preferentially expressed in the central regions of the tumors, suggesting that this negative correlation between TGFβ and NIS occurs locally inside the tumor. Our study describes a novel mechanism of NIS repression in thyroid cancer and provides evidence that TGFβ may play a key role in promoting radioiodide resistance and tumor invasion during PTC progression. [Cancer Res 2009;69(21):8317–25]
Heat Shock Protein 90 Inhibitors: New Mode of Therapy to Overcome Endocrine Resistance
Authors: Wong Cynthie , Chen Shiuan
Published: October 2009

Aromatase inhibitors are important drugs to treat estrogen receptor α (ERα)–positive postmenopausal breast cancer patients. However, development of resistance to aromatase inhibitors has been observed. We examined whether the heat shock protein 90 (HSP90) inhibitor 17-(dimethylaminoethylamino)-17-demethoxygeldanamycin (17-DMAG) can inhibit the growth of aromatase inhibitor–resistant breast cancers and the mechanisms by which 17-DMAG affects proliferation. Aromatase inhibitor–responsive MCF-7aro and aromatase inhibitor–resistant LTEDaro breast epithelial cells were used in this study. We observed that 17-DMAG inhibited proliferation in both MCF-7aro and LTEDaro cells in a dose-dependent manner. 17-DMAG induced apoptosis and G2 cell cycle arrest in both cell lines. Although inhibition of HSP90 decreased the levels of ERα, the ERα transcriptional activity was not affected when cells were treated with 17-DMAG together with estradiol. Moreover, detailed mechanistic studies suggested that 17-DMAG inhibits cell growth via degradation of HSP90 client proteins AKT and HER2. Collectively, results from this study provide data to support that HSP90 inhibitors may be an effective therapy to treat aromatase inhibitor–resistant breast cancers and that improved efficacy can be achieved by combined use of a HSP90 inhibitor and an AKT inhibitor. [Cancer Res 2009;69(22):8670–7]
Nuclear Translocation of the Epidermal Growth Factor Receptor Family Membrane Tyrosine Kinase Receptors
Authors: Wang Shao-Chun , Hung Mien-Chie
Published: October 2009

Integral membrane proteins contain a hydrophobic transmembrane domain and mainly locate in the plasma membrane lipid bilayer. The receptor tyrosine kinases (RTK) of the epidermal growth factor receptor (EGFR) superfamily, including ErbB-1, ErbB-2, ErbB-3, and ErbB-4, constitute an important group of such membrane proteins, which have a profound impact on cancer initiation, progression, and patient outcome. Although studies of their functions have conventionally focused on their membrane-associated forms, documented observations of the presence of these membrane receptors and their functioning partners in the nucleus have reshaped the intracellular geography and highlight the need to modify the central dogma. The ErbB proteins in the membrane can translocate to the nucleus through different mechanisms. Nuclear RTKs regulate a variety of cellular functions, such as cell proliferation, DNA damage repair, and signal transduction, both in normal tissues and in human cancer cell. In addition, they play important roles in determining cancer response to cancer therapy. Nuclear presence of these ErbB proteins is emerging as an important marker in human cancers. An integrated picture of the RTK-centered signaling transduction network extending from the membrane-cytoplasm boundary to the nuclear compartment is looming in the foreseeable horizon for clinical application. (Clin Cancer Res 2009;15(21):6484–9)
Targeted Radionuclide Therapy Using a Wnt-Targeted Replicating Adenovirus Encoding the Na/I Symporter
Authors: Peerlinck Inge , Merron Andrew , Baril Patrick , Conchon Sophie , Martin-Duque Pilar , Hindorf Cécilia , Burnet Jerome , Quintanilla Miguel , Hingorani Mohan , Iggo Richard , Lemoine Nick R. , Harrington Kevin , Vassaux Georges
Published: October 2009

Purpose: The Na/I symporter (hNIS) promotes concentration of iodine in cells. In cancer gene therapy, this transgene has potential as a reporter gene for molecular imaging of viral biodistribution and as a therapeutic protein promoting 131I-mediated radiotherapy. Here, we combined the imaging and therapeutic potential of hNIS in an oncolytic adenoviruses targeting colorectal cancer cells.

Experimental Design: We generated an adenovirus (AdIP2) encoding hNIS and capable of selective replication in colorectal carcinoma cells. The selectivity of this virus was verified in vitro and in vivo. Its spread in tumors was monitored in vivo using single-photon emission computed tomography/CT imaging upon 99mTcO4− injection and confirmed by immunohistochemistry. Metabolic radiotherapy was done through injection of therapeutic doses of 131I−.

Results: We showed in vitro and in vivo the selectivity of AdIP2 and that hNIS expression is restricted to the target cells. Imaging and immunohistochemical data showed that viral spread is limited and that the point of maximal hNIS expression is reached 48 hours after a single intratumoral injection. Administration of a single therapeutic dose of 131I at this time point led to a dramatic reduction in tumor size not observed in hNIS-negative viruses.

Conclusions: This report showed for the first time that the combination of the imaging and therapeutic potentials of hNIS can be applied to oncolytic adenoviruses in experimental models of cancer. (Clin Cancer Res 2009;15(21):6595–601)
JNJ-26481585, a Novel Second-Generation Oral Histone Deacetylase Inhibitor, Shows Broad-Spectrum Preclinical Antitumoral Activity
Authors: Arts Janine , King Peter , Marin Ann , Floren Wim , Belin Ann , Janssen Lut , Pilatte Isabelle , Roux Bruno , Decrane Laurence , Gilissen Ron , Hickson Ian , Vreys Veronique , Cox Eugene , Bol Kees , Talloen Willem , Goris Ilse , Andries Luc , Du Jardin Marc , Janicot Michel , Page Martin , van Emelen Kristof , Angibaud Patrick
Published: October 2009

Purpose: Histone deacetylase (HDAC) inhibitors have shown promising clinical activity in the treatment of hematologic malignancies, but their activity in solid tumor indications has been limited. Most HDAC inhibitors in clinical development only transiently induce histone acetylation in tumor tissue. Here, we sought to identify a second-generation class I HDAC inhibitor with prolonged pharmacodynamic response in vivo, to assess whether this results in superior antitumoral efficacy.

Experimental Design: To identify novel HDAC inhibitors with superior pharmacodynamic properties, we developed a preclinical in vivo tumor model, in which tumor cells have been engineered to express fluorescent protein dependent on HDAC1 inhibition, thereby allowing noninvasive real-time evaluation of the tumor response to HDAC inhibitors.

Results: In vivo pharmacodynamic analysis of 140 potent pyrimidyl-hydroxamic acid analogues resulted in the identification of JNJ-26481585. Once daily oral administration of JNJ-26481585 induced continuous histone H3 acetylation. The prolonged pharmacodynamic response translated into complete tumor growth inhibition in Ras mutant HCT116 colon carcinoma xenografts, whereas 5-fluorouracil was less active. JNJ-26481585 also fully inhibited the growth of C170HM2 colorectal liver metastases, whereas again 5-fluorouracil/Leucovorin showed modest activity. Further characterization revealed that JNJ-26481585 is a pan-HDAC inhibitor with marked potency toward HDAC1 (IC50, 0.16 nmol/L).

Conclusions: The potent antitumor activity as a single agent in preclinical models combined with its favorable pharmacodynamic profile makes JNJ-26481585 a promising second-generation HDAC inhibitor. The compound is currently in clinical studies, to evaluate its potential applicability in a broad spectrum of both solid and hematologic malignancies. (Clin Cancer Res 2009;15(22):684151)
DNA Variants in Region for Noncoding Interfering Transcript of Dihydrofolate Reductase Gene and Outcome in Childhood Acute Lymphoblastic Leukemia
Authors: Al-Shakfa Fidaa , Dulucq Stphanie , Brukner Ivan , Milacic Iva , Ansari Marc , Beaulieu Patrick , Moghrabi Albert , Laverdire Caroline , Sallan Stephen E. , Silverman Lewis B. , Neuberg Donna , Kutok Jeffery L. , Sinnett Daniel , Krajinovic Maja
Published: October 2009

Purpose: Dihydrofolate reductase (DHFR) is the major target of methotrexate, a key component in childhood acute lymphoblastic leukemia (ALL) treatment. We recently reported an association of DHFR promoter polymorphisms with ALL outcome. Lower event-free survival correlated with haplotype *1, defined by A317 and C1610 alleles. Haplotype *1 was also associated higher DHFR expression.

Experimental Design: Here, we analyzed adjacent 400-bp region participating in DHFR regulation as both a major promoter and a noncoding minor transcript.

Results: Six polymorphisms were identified, of which five were single nucleotide polymorphisms and one was length polymorphism composed of variable number of 9-bp elements and 9-bp insertion/deletion. Haplotype analysis including all promoter polymorphisms revealed diversification of haplotype *1 into five subtypes (*1a-*1e). DNA variations of major promoter/noncoding transcript region and haplotype *1 subtypes were subsequently analyzed for the association with ALL outcome. Lower event-free survival was associated with an A allele of G308A polymorphism (P = 0.02) and with *1b haplotype (P = 0.01). This association was particularly striking in high-risk patients (P = 0.001) and was subsequently confirmed in independent patient cohort (P = 0.02). Haplotype *1b was the only haplotype *1 subtype associated with higher mRNA levels.

Conclusions: The study provides a new insight into DHFR regulatory variations predisposing to an event in ALL patients. (Clin Cancer Res 2009;15(22):69318)
In vitro and Clinical Studies of Gene Therapy with Recombinant Human Adenovirus-p53 Injection for Oral Leukoplakia
Authors: Li Yi , Li Long-Jiang , Zhang Song-Tao , Wang Li-Juan , Zhang Zhuang , Gao Ning , Zhang Yuan-Yuan , Chen Qian-Ming
Published: October 2009

Purpose: Oral leukoplakia is a well-recognized precancerous lesion of squamous cell carcinoma. When accompanied with abnormal p53 expression, it suffered a higher risk of canceration. The present study was carried out to test whether the recombinant human adenovirus-p53 could introduce wild-type p53 gene to oral leukoplakia cells and induce cell cycle arrest and apoptosis.

Experimental Design: We select p53(−) oral dysplastic keratinocyte POE-9n, to observe the growth inhibition, cell cycle change, apoptosis-induced effects, and elaborate the corresponding molecular mechanism of recombinant adenovirus-p53 on POE-9n cells. Meanwhile, we evaluate the feasibility, safety, and biological activity of multipoints intraepithelial injections of recombinant adenovirus-p53 in 22 patients with dysplastic oral leukoplakia.

Results: Exogenous p53 could be successfully transduced into POE-9n cells by recombinant adenovirus-p53. The optimal infecting titer in this study was multiplicity of infection (MOI) = 100. Recombinant adenovirus-p53 could strongly inhibit cell proliferation, induce apoptosis, and arrest cell cycle in stage G1 in POE-9n cells by inducing p21CIP/WAF and downregulating bcl-2 expression. In the posttreatment patients, p53 protein and p21CIP/WAF protein expression were significantly enhanced, yet bcl-2 protein presented low expression. Sixteen patients showed clinical response to the treatment, and 14 patients showed obvious histopathologic improvement.

Conclusion: Intraepithelial injections of recombinant human adenovirus-p53 were safe, feasible, and biologically active for patients with dysplastic oral leukoplakia. (Clin Cancer Res 2009;15(21):6724–31)
Differential Cellular Responses to Prolonged LDR-IR in MLH1-Proficient and MLH1-Deficient Colorectal Cancer HCT116 Cells
Authors: Yan Tao , Seo Yuji , Kinsella Timothy J.
Published: October 2009

Purpose: MLH1 is a key DNA mismatch repair (MMR) protein involved in maintaining genomic stability by participating in the repair of endogenous and exogenous mispairs in the daughter strands during S phase. Exogenous mispairs can result following treatment with several classes of chemotherapeutic drugs, as well as with ionizing radiation. In this study, we investigated the role of the MLH1 protein in determining the cellular and molecular responses to prolonged lowdose rate ionizing radiation (LDR-IR), which is similar to the clinical use of cancer brachytherapy.

Experimental Design: An isogenic pair of MMR+ (MLH1+) and MMR (MLH1) human colorectal cancer HCT116 cells was exposed to prolonged LDR-IR (1.3-17 cGy/h 24-96 h). The clonogenic survival and gene mutation rates were examined. Cell cycle distribution was analyzed with flow cytometry. Changes in selected DNA damage repair proteins, DNA damage response proteins, and cell death marker proteins were examined with Western blotting.

Results: MLH1+ HCT116 cells showed greater radiosensitivity with enhanced expression of apoptotic and autophagic markers, a reduced HPRT gene mutation rate, and more pronounced cell cycle alterations (increased late-S population and a G2/M arrest) following LDR-IR compared with MLH1 HCT116 cells. Importantly, a progressive increase in MLH1 protein levels was found in MLH1+ cells during prolonged LDR-IR, which was temporally correlated with a progressive decrease in Rad51 protein (involved in homologous recombination) levels.

Conclusions: MLH1 status significantly affects cellular responses to prolonged LDR-IR. MLH1 may enhance cell radiosensitivity to prolonged LDR-IR through inhibition of homologous recombination (through inhibition of Rad51). (Clin Cancer Res 2009;15(22):691220)
Efficacy of IGFBP7 for treatment of metastatic melanoma and other cancers in mouse models and human cell lines
Authors: Wajapeyee Narendra , Kapoor Varun , Mahalingam Meera , Green Michael R.
Published: October 2009

We recently identified the secreted protein IGFBP7 as a factor required for an activated BRAF oncogene to induce senescence or apoptosis in primary human cells. In human melanomas containing an activating BRAF mutation (BRAF-positive melanomas), IGFBP7 is epigenetically silenced, which seems to be a critical step in melanoma genesis. Restoration of IGFBP7 function by the addition of recombinant IGFBP7 (rIGFBP7) induces apoptosis in BRAF-positive human melanoma cell lines, and systemically administered rIGFBP7 markedly suppresses the growth of BRAF-positive primary tumors in xenografted mice. Here we further evaluate the role of IGFBP7 in the treatment of BRAF-positive melanoma and other malignancies. We find that in human metastatic melanoma samples IGFBP7 is epigenetically silenced and at an even higher frequency than that found in primary melanomas. Using a murine experimental metastasis assay, we show that systemic administration of rIGFBP7 markedly suppresses the growth of metastatic disease and prolongs survival. An analysis of the NCI60 panel of human cancer cell lines reveals that in addition to melanoma, IGFBP7 induces apoptosis in several other cancer types, in particular colorectal cancer cell lines. In general, IGFBP7 induces apoptosis in human cancer cell lines that have an activating mutation in BRAF or RAS, and that are sensitive to chemical inhibition of BRAF-MEK-ERK signaling. Significantly, systemically administered rIGFBP7 blocks the growth of colorectal tumors containing an activating RAS or BRAF mutation in mouse xenografts. The results presented here, in conjunction with those from previous studies, justify the further development of IGFBP7 as an anticancer agent. [Mol Cancer Ther 2009;8(11):3009–14]