bluuebunny/crossref_metadata_2025 huggingface dataset:
Mites of family Macrochelidae (Acari: Gamasida) associated with dung beetles in Mt Merapi National Park, Jogyakarta, Java, Indonesia
Authors: HARTINI Sri , DWIBADRA Dhian , TAKAKU Gen
Published: December 2009

Fourteen mite species in three genera of the family Macrochelidae were collected from the body surface of dung beetles (Scarabaeidae) in Mt Merapi National Park, Jogyakarta, Indonesia. Of these, three species, Macrocheles turgoensis n. sp., M. pumilus n. sp. and Glyptholaspis merapiensis n. sp., were described as new to science. The remaining 11 species were Glyptholaspis fimicola (Sellnick, 1931), Neopodocinum spinirostris (Berlese, 1910), M. dispar (Berlese, 1910), M. entetiensis Hartini and Takaku, 2005, M. hallidayi Walter and Krantz, 1986, M. jabarensis Hartini and Takaku, 2003, M. merdarius (Berlese, 1889), M. muscaedomesticae (Scopoli, 1772), M. oigru Walter and Krantz, 1986, M. sukaramiensis Takaku, 2001 and M. sp. aff. glaber (Müller, 1860).
Effects of nematode parasitism on mycophagous drosophilid species in northern Japan
Authors: YOROZUYA Hiroshi
Published: December 2009

Mycophagous drosophilids and their nematode parasites were studied in an intensive census conducted throughout the active season over four years (2000–2003) in Hokkaido, northern Japan. Using census data, I assessed the prevalence of nematode parasitism through seasons, determined its effects on drosophilid female fertility and tested the “disproportionate parasitism hypothesis” to evaluate its effects on drosophilid community structure. Over the four‐year census, a total of 43 fungal species were found on the census route and 18 177 adult drosophilid flies were collected. The yearly parasitism rate on the total drosophilid community varied from 6.2% in 2000 to 5.1% in 2001 and 3.0% in 2002 and 2003. There was strong seasonal variation in the prevalence of parasitism. In addition, parasitism rates varied among drosophilid species. All parasitized females carried only small numbers of eggs. Thus, nematode parasitism had a strong deleterious effect on the fitness of infected flies. The relative abundance of drosophilid species and parasitism rate were not significantly correlated. Thus, the disproportionate parasitism hypothesis likely does not apply to the mycophagous drosophilid community in Japan.
The Effect of Life Cycle Cost Information on Consumer Investment Decisions Regarding Eco‐Innovation
Authors: Kaenzig Josef , Wüstenhagen Rolf
Published: December 2009

Life cycle cost (LCC) computations are a well‐established instrument for the evaluation of intertemporal choices in organizations, but they have not been widely adopted by private consumers yet. Consumer investment decisions for products and services with higher initial costs and lower operating costs are potentially subject to numerous cognitive biases, such as present‐biased preferences or framing effects. This article suggests a classification for categorizing different cost profiles for eco‐innovation and a conceptual model for the influence of LCC information on consumer decisions regarding eco‐innovation. It derives hypotheses on the decision‐making process for eco‐innovation from a theoretical perspective. To verify the hypotheses, the publication reviews empirical studies evaluating the effects of LCC information on consumer investment decisions. It can be concluded that rather than finding ways to make customers pay more for environmentally sound products, the marketing challenge for eco‐innovation should be reconceptualized as one of lowering customers’ perceived initial cost and increasing awareness of LCC. Most existing studies report a positive effect of LCC information on the purchase likelihood of eco‐innovations. Disclosing LCC information provides an important base for long‐term thinking on the individual, corporate, and policy levels.
The role of CTGF in the diabetic rat retina and its relationship with VEGF and TGF‐β2, elucidated by treatment with CTGFsiRNA
Authors: Yang Hongwei , Huang Yonggang , Chen Xiaolong , Liu Jie , Lu Yan , Bu Limin , Xia Likun , Xiao Wei , Chen Ming , Nie Qingzhu , Liu Zheli
Published: December 2009

Acta Ophthalmol. 2010: 88: 652–659

Purpose:  The critical association of connective tissue growth factor (CTGF) with diabetic retinopathy (DR) remains to be clarified. We detected alterations in the gene and protein expression of CTGF and related cytokines, including vascular endothelial growth factor (VEGF) and transforming growth factor‐β2 (TGF‐β2), and their response to small interfering RNA (siRNA) targeting the CTGF (CTGFsiRNA) in the retina of diabetic rats. The relationships between CTGF, VEGF and TGF‐β2 levels, as well as the degree of apoptosis in the diabetic retina, were also investigated.

Methods:  Diabetes was induced in rats by the β‐cell toxin streptozotocin (STZ). Retinas were obtained from control and diabetic rats and similar animals treated with CTGFsiRNA by intravitreal injection. mRNA level and protein expression of CTGF, VEGF and TGF‐β2 were measured by reverse transcription‐polymerase chain reaction (RT‐PCR) and Western blotting, and located by immunohistochemistry. Retinal apoptosis was detected by TUNEL staining.

Results:  The levels of CTGF, VEGF and TGF‐β2 and the number of TUNEL‐positive nuclei were significantly higher in diabetic retinas than in control retinas (p < 0.01). The level of CTGF rose at 8 weeks, earlier than levels of VEGF and TGF‐β2, which rose at 12 weeks after the onset of diabetes. The difference was significant (p < 0.05). siRNA‐mediated inhibition of CTGF mRNA inhibited retinal VEGF and TGF‐β2 and also resulted in a significant decrease in apoptosis. Significant correlations were found between CTGF and VEGF (p = 0.009), CTGF and TGF‐β2 (p = 0.01), and apoptosis and these three cytokines (p < 0.01) in the rat retina early in diabetes.

Conclusions:  These results suggest that the diabetes‐mediated increase in CTGF upregulates VEGF and TGF‐β2 expression and induces apoptosis in the retina. This elevation may be inhibited by treatment with CTGFsiRNA. Connective tissue growth factor may serve as a potential target for the prevention and treatment of DR.
The Paradox of Transparency, Short‐Termism and the Institutionalisation of Australian Capital Markets
Authors: Nicholson Gavin , Cook Zoie
Published: December 2009

As the ultimate corporate decision‐makers, directors have an impact on the investment time horizons of the corporations they govern. How they make investment decisions has been profoundly influenced by the expansion of the investment chain and the increasing concentration of share ownership in institutional hands. By examining agency in light of legal theory, we highlight that the board is in fact sui generis and not an agent of shareholders. Consequently, transparency can lead to directors being ‘captured’ by institutional investor objectives and timeframes, potentially to the detriment of the corporation as a whole. The counter‐intuitive conclusion is that transparency may, under certain conditions, undermine good corporate governance and lead to excessive short‐termism.
Discount Rates in Disarray: Evidence on Flawed Goodwill Impairment Testing
Authors: Carlin Tyrone M. , Finch Nigel
Published: December 2009

Discount rate selection represents a centrally material factor impacting valuation models. Given the strong reliance on discounted cash flow modelling as a basis for determining an asset's recoverable amount, the judgement exercised by reporting entities regarding rate selection is of paramount importance in influencing the outcomes of the impairment testing process conducted under International Financial Reporting Standards (IFRS). The discretion surrounding rate selection could be used opportunistically to avoid or manage the timing of impairment losses to the detriment of transparency, comparability and decision usefulness. This study provides evidence consistent with the opportunism on the part of financial statement preparers, by demonstrating the existence of variances between independently generated risk‐adjusted discount rates and those disclosed as having been used by a sample of large listed Australian companies.
Combined
ramR
Mutation and Presence of a Tn
1721
-Associated
tet
(A) Variant in a Clinical Isolate of
Salmonella enterica
Serovar Hadar Resistant to Tigecycline
Authors: Hentschke M. , Christner M. , Sobottka I. , Aepfelbacher M. , Rohde H.
Published: December 2009

A
Salmonella enterica
serovar Hadar strain resistant to tigecycline (MIC, 16 μg/ml) was isolated. Molecular characterization revealed the presence of a plasmid-borne
tet
(A) variant associated with Tn
1721
mediating a rise of the MIC for tigecycline when transferred to
Escherichia coli
. Additionally, a truncating mutation in
ramR
was detected. Transformation with wild-type
ramR
but not with the mutated
ramR
lowered the MIC for tigecycline. Characterization of this
Salmonella
isolate implicates
ramR
in resistance to tigecycline.
Spread of a Chromosomal Cefixime-Resistant
penA
Gene among Different
Neisseria gonorrhoeae
Lineages
Authors: Ohnishi Makoto , Watanabe Yuko , Ono Emi , Takahashi Chieko , Oya Hitomi , Kuroki Toshiro , Shimuta Ken , Okazaki Norio , Nakayama Shu-ichi , Watanabe Haruo
Published: December 2009

In
Neisse
ria gonorrhoeae
, the mosaic type of
penA
, which encodes penicillin-binding protein 2 (PBP 2), is associated with reduced susceptibility to oral cephalosporins. To investigate the relatedness of
N. gonorrhoeae
clinical isolates with reduced susceptibility, we sequenced the
penA
genes of 32 isolates. Five different amino acid sequence types of PBP 2 were identified, but all seemed to be derivatives of pattern X of PBP 2 (PBP 2-X). However, multilocus sequence typing of the isolates showed that the isolates belonged to six different sequence types. As PBP 2-X was identified in three different sequence types, horizontal transfer of the
penA
allele encoding PBP2-X was suggested. We demonstrated that the
penA
gene could be transferred from an isolate with reduced susceptibility to a sensitive isolate by natural transformation. Comparison of the sequence of the
penA
-flanking regions of 12 transformants with those of the donor and the recipient suggested that at least a 4-kb DNA segment, including the
penA
gene, was transferred. During horizontal transfer, some of the
penA
alleles also acquired variations due to point mutations and genetic exchange within the allele. Our results provide evidence that the capacity for natural transformation in
N. gonorrhoeae
plays a role in the spread of chromosomal antibiotic resistance genes and the generation of diversity in such genes.
Early Viral Kinetics of Telbivudine and Entecavir: Results of a 12-Week Randomized Exploratory Study with Patients with HBeAg-Positive Chronic Hepatitis B
Authors: Suh Dong Jin , Um Soon Ho , Herrmann Eva , Kim Ju-Hyun , Lee Young Sok , Lee Heon Ju , Lee Myung Seok , Lee Youn-Jae , Bao Weibin , Lopez Patricia , Lee Han Chu , Avila Claudio , Zeuzem Stefan
Published: December 2009

We characterized the early viral kinetic profiles of telbivudine and entecavir and the effects of these potent nucleoside analogs on hepatitis B virus (HBV) DNA and alanine aminotransferase levels in adults with hepatitis B e antigen-positive compensated chronic hepatitis B. Forty-four patients were enrolled in this open-label, parallel-group, multicenter study and randomized to receive telbivudine or entecavir for 12 weeks. Reductions in hepatitis B virus DNA and alanine aminotransferase levels from baseline to weeks 2, 4, 8, and 12 were assessed. Viral kinetic parameters, including viral clearance per day, loss of infected cells per day, and efficiency of inhibition of viral production, were estimated by using a biphasic mathematical model. Statistical analyses were limited to descriptive analyses. The 2 treatment groups achieved similar reductions in HBV DNA and alanine aminotransferase levels. Mean reductions in levels of hepatitis B virus DNA at week 12 were 6.6 ± 1.6 and 6.5 ± 1.5 log10copies/ml for the telbivudine- and entecavir-treated patients, respectively. There were no significant differences between groups in values for mean viral clearance per day, mean loss of infected cells per day, or efficiency of blocking viral production. The safety profiles for both medications were favorable. During the first 12 weeks of treatment, telbivudine and entecavir demonstrated similar antiviral potencies, resulting in a rapid and profound suppression of serum hepatitis B virus DNA and reduction of alanine aminotransferase levels. No differences in the effects of these 2 agents on early viral kinetics were observed. Both medications were well tolerated.
Exploiting the Drug-Activating Properties of a Novel Trypanosomal Nitroreductase
Authors: Hall Belinda S. , Wu Xinghua , Hu Longqin , Wilkinson Shane R.
Published: December 2009

Nitroheterocyclic prodrugs have been used to treat trypanosomal diseases for more than 40 years. Recently, the key step involved in the activation of these compounds has been elucidated and shown to be catalyzed by a type I nitroreductase (NTR). This class of enzyme is normally associated with bacteria and is absent from most eukaryotes, with trypanosomes being a major exception. Here we exploit this difference by evaluating the trypanocidal activity of a library of nitrobenzylphosphoramide mustards against bloodstream-form
Trypanosoma brucei
parasites. Biochemical screening against the purified enzyme revealed that a subset of halogenated nitroaromatic compounds were effective substrates for
T. brucei
NTR (TbNTR), having apparent
K
cat
/

K
m

values approximately 100 times greater than nifurtimox. When tested against
T. brucei
, cytotoxicity mirrored enzyme activity, with 50% inhibitory concentrations of the most potent substrates being less than 10 nM.
T. brucei
NTR plays a key role in parasite killing: heterozygous lines displayed resistance to the compounds, while parasites overexpressing the enzyme showed hypersensitivity. We also evaluated the cytotoxicities of substrates with the highest trypanocidal activities by using mammalian THP-1 cells. The relative toxicities of these newly identified compounds were much lower than that of nifurtimox. We conclude that halogenated nitrobenzylphosphoramide mustards represent a novel class of antitrypanosomal agents, and their efficacy validates the strategy of specifically targeting NTR activity to develop new therapeutics.
AtolCMutant ofFrancisella tularensisIs Hypercytotoxic Compared to the Wild Type and Elicits Increased Proinflammatory Responses from Host Cells
Authors: Platz Gabrielle J. , Bublitz DeAnna C. , Mena Patricio , Benach Jorge L. , Furie Martha B. , Thanassi David G.
Published: December 2009

The highly infectious bacteriumFrancisella tularensisis a facultative intracellular pathogen and the causative agent of tularemia. TolC, which is an outer membrane protein involved in drug efflux and type I protein secretion, is required for the virulence of theF. tularensislive vaccine strain (LVS) in mice. Here, we show that an LVS ΔtolCmutant colonizes livers, spleens, and lungs of mice infected intradermally or intranasally, but it is present at lower numbers in these organs than in those infected with the parental LVS. For both routes of infection, colonization by the ΔtolCmutant is most severely affected in the lungs, suggesting that TolC function is particularly important in this organ. The ΔtolCmutant is hypercytotoxic to murine and human macrophages compared to the wild-type LVS, and it elicits the increased secretion of proinflammatory chemokines from human macrophages and endothelial cells. Taken together, these data suggest that TolC function is required forF. tularensisto inhibit host cell death and dampen host immune responses. We propose that, in the absence of TolC,F. tularensisinduces excessive host cell death, causing the bacterium to lose its intracellular replicative niche. This results in lower bacterial numbers, which then are cleared by the increased innate immune response of the host.
Heckethornia, a new genus of dimeropygid trilobites from the Lower Ordovician (Ibexian; Tulean and Blackhillsian) of the Great Basin, western USA
Authors: McAdams Neo E.B. , Adrain Jonathan M.
Published: December 2009

Heckethornia n. gen. is a morphologically striking clade of dimeropygid trilobites known from the Pogonip Group (Ordovician; Ibexian Series, Tulean and Blackhillsian stages) of western Utah and eastern Nevada. It includes seven species based on silicified material. All occur in the Fillmore Formation of western Utah, and four are also known from the Yellow Hill Limestone of eastern Nevada. Diagnostic features of Heckethornia include a highly vaulted exoskeleton with a tall pygidial “wall” made of fused outer pleurae, three pairs of large glabellar spines, two to three pairs of prominent pygidial spines, a single (or paired) large occipital spine(s), and an arc of tubercles on the librigenal field. Cladistic parsimony analysis suggests that the genus comprises two subclades, one including species with a single median occipital spine, and species with paired occipital spines or tubercles in the other. New species are H. smithi , H. hyndeae , H. numani , H. bowiei , H. morrisseyi , and H. ballionae .
Mesoproterozoic carbonate systems in the Borden Basin, Nunavut
Authors: Turner Elizabeth C.
Published: December 2009

Existing stratigraphic nomenclature, lithologic descriptions, and geological interpretations for an economically important Mesoproterozoic dolostone in the Milne Inlet Graben, Borden Basin, Nunavut, do not adequately portray its unusual facies or their spatio-temporal configuration. Four new stratigraphic units are introduced to replace this dolostone, formerly known as the Society Cliffs Formation. In the southeastern half of the graben, the Iqqittuq Formation represents a distally steepened ramp that grades northwestward into deep-water mudstone that is indistinguishable from that of the underlying Arctic Bay Formation. The overlying Angmaat Formation represents a rimmed, restricted peritidal platform that grades northwestward across a tepee – cortoid shoal barrier into the unusual, deep-water dolo-laminite of the Nanisivik Formation. Deep-water carbonate mounds up to hundreds of metres thick and kilometres in areal dimensions belong to the Ikpiarjuk Formation; these mounds are geometrically equivalent to upper Arctic Bay Formation mudstone, Iqqittuq Formation outermost ramp, and part of the Nanisivik Formation dolostone. The Iqqittuq, Nanisivik, and Ikpiarjuk formations conformably overlie mudstone of the Arctic Bay Formation. The Angmaat and Nanisivik formations are unconformably overlain by mudstone of the lower Victor Bay Formation. These new, formal, mappable stratigraphic entities were deposited in two time stages, and their three-dimensional configuration depicts an unusual, tectonically influenced basin that was also affected by high-amplitude eustatic cyclicity in shallow water.
Plume–lithosphere interaction and crustal contamination during formation of Coppermine River basalts, Northwest Territories, Canada
Authors: Griselin Mélanie , Arndt Nicholas T. , Baragar W. R. A.
Published: December 2009

New trace-element and Nd-isotope analyses were carried out on the Coppermine River basalts, a suite of 1.27 Ga old continental flood basalts in the Northwest Territories of Canada. Although all the samples are tholeiitic basalts, their chemical and isotopic compositions change upwards in the sequence. The lowermost unit has relatively high contents of SiO2 and incompatible trace elements, high ratios of elements with different compatibilities (e.g., Th/Nb, La/Sm), high Gd/Yb, negative Nb anomalies, and low εNd. Samples at the top of the sequence have less pronounced enrichment and fractionation of incompatible elements coupled with an absence of Nb anomalies and positive εNd values. These results are interpreted to indicate that the lavas lowest in the sequence were produced by melting in the garnet stability field, at depths greater than 90 km, and probably in a mantle plume beneath the continental lithosphere. These magmas passed through magma chambers in the lower and upper crust where they became contaminated with crustal rocks. During the course of the eruption of the entire volcanic sequence the extent of crustal contamination became minimal and the lavas lost the chemical signature of residual garnet. The youngest lavas formed by melting in the spinel field and were free of crustal contamination. The site of mantle melting apparently became shallower, perhaps because of lithosphere thinning.
Time of metamorphism beneath the Central Metasedimentary Belt boundary thrust zone, Grenville Orogen, Ontario: accretion at 1080 Ma?
Authors: Timmermann H. , Jamieson R. A. , Culshaw N. G. , Parrish R. R.
Published: December 2009

New U–Pb zircon and titanite data from the Muskoka domain, Grenville Province, Ontario, provide protolith and metamorphic ages for the southwestern Central Gneiss Belt. Discordant analyses from a migmatitic orthogneiss and its leucosome form a linear array with an upper intercept age of 1457 ± 6 Ma and a lower intercept age of 1064 ±18 Ma. U–Pb analyses on metamorphic zircon from an amphibolite yield a set of concordant analyses with an average 207Pb/206Pb age of 1079 ± 3 Ma. A weakly migmatitic granitoid rock and a transecting charnockitic vein in the immediate footwall of the Central Metasedimentary Belt boundary thrust zone yielded a discordant array of analyses wth an upper intercept age of 1394 ± 13 Ma and a lower intercept age of 1066 ± 8 Ma. The charnockitic vein yielded concordant zircon ages of 1077 ± 2 Ma. The upper intercept ages are interpreted in terms of protolith crystallization, and the concordant and lower intercept ages as Grenviilian high-grade metamorphism and associated anatexis. We have found no evidence for a ca. 1190–1160 Ma metamorphic event in these rocks, as required by some regional tectonic interpretations. We conclude that emplacement of the Central Metasedimentary Belt over the Central Gneiss Belt, which caused high-grade metamorphism in the Muskoka domain, occurred at or shortly before ca. 1080 Ma, and that this marks the time of accretion of the Central Metasedimentary Belt to the southeast margin of Laurentia.
On the nature and origin of "muck" deposits in the Klondike area, Yukon Territory
Authors: Fraser T. A. , Burn C. R.
Published: December 2009

Organic-rich "muck" deposits, which blanket auriferous gravels in the Klondike area, Yukon Territory, comprise two principal stratigraphic units: (i) a silty Late Pleistocene deposit, and (ii) Holocene organics lying unconformably on the silt. The deposits are found predominantly in valley bottoms and, if undisturbed, are normally perennially frozen. Field and laboratory investigations of particle size, mineralogy, and morphology, as well as organic matter and sedimentary structures, indicate that the silt is both primary (massive) and redeposited (bedded) loess (by weight 87% medium and coarse silt and fine sand). Radiocarbon dates indicate that the loess was deposited during Late Wisconsinan McConnell glaciation, beginning after 27 000 14C years BP. The loess was likely derived from the floodplain of the Yukon River during periods of low flow. Turf in growth position and organic matter in the silt similar to that of loessal grasslands near Kluane Lake suggest a grassland environment for the area during McConnell glaciation. A mummified carcass in the silts indicates that some of these sediments have been frozen since shortly after deposition. Ice wedges are commonly found in the upper portion of the silt, but these wedges rarely extend into the overlying organic material. Separate, smaller ice wedges are found in the Holocene unit. Radiocarbon dates indicate that peat growth began at the start of the Holocene, as in other unglaciated portions of Yukon, when the climate became abruptly wetter.
Iapetus Ocean floor stuffed into a suture zone: xenolith Nd isotopic evidence for Dunnage-equivalent basement in central Newfoundland
Authors: Fryer Brian J. , Greenough John D. , Owen J. Victor
Published: December 2009

Granulite-facies xenoliths from Late Jurassic alkaline lamprophyres may represent basement to the Dunnage Zone in north-central Newfoundland (Notre Dame Bay area). At 143 Ma the xenoliths had positive εNd values between 0.9 and 4.7. They give Nd depleted mantle model ages around 700 Ma and have trace element and major element compositions reminiscent of oceanic arc-related intermediate volcanic and sedimentary rocks. Their positive εNd values and associated "young" Nd model ages argue against their representing Grenvillian crust. Similarly, Gander Zone basement to the east produced granitic rocks with strongly negative εNd values unlike those of the xenoliths. Positive εNd values for Avalonian granites indicate that the xenoliths could represent Avalon-type basement; however, there are 100–200 km of Gander and Dunnage zone rocks between the xenoiith locality and the Avalon Zone. Early orogenic volcanic rocks and some late orogenic to postorogenic granitic rocks in the central to northern portion of the Gander Zone have positive εNd values, consistent with extraction from a depleted mantle at the same time as material forming the xenoliths. Similarities between the xenolith chemistry and that of early orogenic (Cambrian) arc-related intermediate volcanic rocks of the Dunnage Zone indicate that the xenoliths and basement in the Notre Dame Bay area are composed of Iapetus Ocean floor relics (volcanic or volcanic-rich sedimentary rocks) stuffed into a collisional suture zone during ocean closure.
Calving From Ward–Hunt Ice Shelf, 1961–1962
Authors: Holdsworth G.
Published: December 2009

Tide records available from Alert, N.W.T. provide a possible basis for identifying more closely the time of the massive calving of the outer part of the Ward–Hunt Ice Shelf in the winter of 1961–1962. The event was possibly a result of a combination of influences. The time interval in which this event probably occurred is given as from February 6 (± 2 days) to March 6, 1962. The former date coincides with a 9% increase above the mean of the maximum difference between high and low water in a 6 h period. On February 4 a seismic shock occurred close to the ice shelf and March 6 identifies the end of a significant downward trend in the monthly plot of lowest low-water.
Observations of postglacial uplift at Churchill, Manitoba
Authors: Tushingham A. Mark
Published: December 2009

Churchill, Manitoba, is located near the centre of postglacial uplift caused by the Earth's recovery from the melting of the Laurentide Ice Sheet. The value of present-day uplift at Churchill has important implications in the study of postglacial uplift in that it can aid in constraining the thickness of the ice sheet and the rheology of the Earth. The tide-gauge record at Churchill since 1940 is examined, along with nearby Holocene relative sea-level data, geodetic measurements, and recent absolute gravimetry measurements, and a present-day rate of uplift of 8–9 mm/a is estimated. Glacial isostatic adjustment models yield similar estimates for the rate of uplift at Churchill. The effects of the tide-gauge record of the diversion of the Churchill River during the mid-1970's are discussed.
A role for cell cycle proteins in the serum-starvation resistance of EpsteinBarr virus immortalized B lymphocytes
Authors: Kim Hak-Ryul , Jeong Ju-Ah , Park Chan-Hee , Lee Suk-Kyeong , Lee Won-Keun , Jang Yong-Suk
Published: December 2009

EpsteinBarr virus (EBV) is a B-lymphotropic human herpes virus that infects B lymphocytes and is associated with a broad spectrum of benign and malignant diseases. B cell infection by EBV causes indefinite cell proliferation that results in the development of immortalized lymphoblastoid cell lines (LCLs). We found that SNU-1103, a latency type III EBV-transformed LCL developed from a Korean cancer patient, resisted the G1 arrest that was normally caused by serum starvation. Western blot analyses revealed several alterations in the expression of key regulatory cell cycle proteins involved in the G1 phase. High expression of cyclin D2 and time-dependent increases in cyclin-dependent kinase 6 (CDK6) and cyclin D3 were observed in SNU-1103 during serum starvation. Very unexpectedly, in SNU-1103, the key G1 phase CDK inhibitor p21Cip1was expressed at a consistently high level, while p27Kip1expression was increased. Of three pRb family proteins, pRb expression was reduced and it became hypophosphorylated in SNU-1103 during serum starvation. Instead, p107 and p130 were expressed at consistently high levels in SNU-1103 during serum starvation. In conclusion, compared with an EBV-negative BJAB cell line, multiple cell cycle regulatory proteins were abnormally or inversely expressed in SNU-1103 during serum starvation.Key words: EpsteinBarr virus, lymphoblastoid cell line, B lymphocyte, serum starvation, cell cycle proteins.
Screening regulatory sequences from bacterial artificial chromosome DNA of alpha- and beta-globin gene clusters
Authors: Zhang Shen , Zhang Hua-Bing , Liu De-Pei , Li Xing-Guo , Hao De-Long , Lv Xiang , Xu Hai-Ming , Liang Chih-Chuan
Published: December 2009

In the forthcoming postgenomic era, identification of regulatory DNA sequences is becoming increasingly important for characterizing DNA-binding proteins and for elucidating the regulatory mechanisms of gene expression. Presently, there lack efficient methods to broadly screen and identify DNA regulatory elements on a large scale. We established herein an efficient strategy to screen regulatory sequences from bacterial artificial chromosome (BAC) DNAs containing human alpha- and beta-globin gene clusters based on polymerase chain reaction and electrophoretic mobility shift assay (EMSA) techniques without purified transcription factors. Twenty-three subclones derived from alpha-BAC DNA by bulk EMSA selection retained the ability to bind nuclear proteins of K562 cells when retested by EMSA. In 19 clones sequenced, 14 are identical to those registered in GenBank and five have one base difference. All of the 24 randomly picked beta-BAC clones showed specific binding with nuclear proteins of K562 cells. In 11 clones sequenced, eight are identical to those registered in GenBank and three have one base difference. This approach could be particularly powerful if combined with other systematic methods for identifying cis-regulatory DNA elements.Key words: gene expression regulation, bacterial artificial chromosome, alpha- and beta-globin gene clusters.
Differential effects of a molybdopterin synthase sulfurylase (moeB) mutation onEscherichia colimolybdoenzyme maturation
Authors: Sambasivarao Damaraju , Turner Raymond J , Bilous Peter T , Rothery Richard A , Shaw Gillian , Weiner Joel H
Published: December 2009

We have generated a chromosomal mutant of moeB (moeBA228T) that demonstrates limited molybdenum cofactor (molybdo-bis(molybdopterin guanine dinucleotide) (Mo-bisMGD)) availability in Escherichia coli and have characterized its effect on the maturation and physiological function of two well-characterized respiratory molybdoenzymes: the membrane-bound dimethylsulfoxide (DMSO) reductase (DmsABC) and the membrane-bound nitrate reductase A (NarGHI). In the moeBA228Tmutant strain, E. coli F36, anaerobic respiratory growth is possible on nitrate but not on DMSO, indicating that cofactor insertion occurs into NarGHI but not into DmsABC. Fluorescence analyses of cofactor availability indicate little detectable cofactor in the moeBA228Tmutant compared with the wild-type, suggesting that NarGHI is able to scavenge limiting cofactor, whereas DmsABC is not. MoeB functions to sulfurylate MoaD, and in the structure of the MoeBMoaD complex, Ala-228 is located in the interface region between the two proteins. This suggests that the moeBA228Tmutation disrupts the interaction between MoeB and MoaD. In the case of DmsABC, despite the absence of cofactor, the twin-arginine signal sequence of DmsA is cleaved in the moeBA228Tmutant, indicating that maturation of the holoenzyme is not cofactor-insertion dependent.Key words: mdybdenum cofactor, DMSO reductase, nitrate reductase.
Conformational changes and inactivation of rabbit muscle creatine kinase in dimethyl sulfoxide solutions
Authors: Ou Wen-bin , Wang Ri-Sheng , Zhou Hai-Meng
Published: December 2009

The effects of dimethyl sulfoxide (DMSO) on creatine kinase (CK) conformation and enzymatic activity were studied by measuring activity changes, aggregation, and fluorescence spectra. The results showed that at low concentrations (<65% v/v), DMSO had little effect on CK activity and structure. However, higher concentrations of DMSO led to CK inactivation, partial unfolding, and exposure of hydrophobic surfaces and thiol groups. DMSO caused aggregation during CK denaturation. A 75% DMSO concentration induced the most significant aggregation of CK. The CK inactivation and unfolding kinetics were single phase. The unfolding of CK was an irreversible process in the DMSO solutions. The results suggest that to a certain extent, an enzyme can maintain catalytic activity and conformation in waterorganic mixture environments. Higher concentrations of DMSO affected the enzyme structure but not its active site. Inactivation occurred along with noticeable conformational change during CK denaturation. The inactivation and unfolding of CK in DMSO solutions differed from other denaturants such as guanidine, urea, and sodium dodecyl sulfate. The exposure of hydrophobic surfaces was a primary reason for the protein aggregation.Key words: creatine kinase, dimethyl sulfoxide, denaturation, activity, conformation.
Changes in Na+-ATPase and Na,K-pump during maturation of sheep reticulocytes
Authors: Blostein Rhoda , Drapeau Pierre , Benderoff Stephen , Weigensberg Andrew M.
Published: December 2009

Changes in the sodium pump and sodium-activated ATP hydrolysis (Na+-ATPase) were followed during maturation of low potassium (LK) and high potassium (HK) sheep reticulocytes released into circulation following massive bleeding. In vitro maturation of LK cell reticulocytes resulted in a progressive decrease in cellular K+, ouabain-sensitive 86Rb+ uptake, and Na+-ATPase activity. Although in vitro maturation (up to 10 days) did not result in changes in kinetic behaviour from that typical of reticulocytes to that typical of mature cells, kinetic changes were clearly evident after longer term maturation in vivo. This was shown for HK cells by comparing the characteristics of Na+-ATPase (response to K+) of the lightest (youngest) and heaviest (oldest) cell fractions of blood obtained at various periods during recovery following massive bleeding. It is concluded that the kinetic difference between immature and mature cells is due to cell maturation and reflects either a selective change and (or) loss of certain type(s) of pump sites.
Rotational mobility associated with the protein moiety of human serum lipoproteins from tryptophan phosphorescence anisotropy measurements
Authors: Kim Heiryun , Galley William C.
Published: December 2009

The steady-state phosphorescence anisotropy of human low density (LDL) and very low density (VLDL) serum lipoproteins in a glycerol–buffer solvent has been investigated. By virtue of the long lifetime of the triplet state, depolarization of the emission resulting from slow rotational motions is observed between −90 and −50 °C. Despite the number of emitting residues within these complexes, the rotational behavior can be represented within experimental error by a single correlation time. The magnitude and temperature dependence of the rotational correlation times observed for LDL are consistent with overall rotation of essentially spherical rigid particles as the source of the phosphorescence depolarization. Preliminary data for VLDL indicate the presence of internal peptide motions which are more rapid than those of the overall complex.
Influence of divalent cations on rat apolipoprotein transfer to synthetic lipoproteinlike lipid emulsions in vitro
Authors: Connelly Philip W. , Kuksis Arnis
Published: December 2009

Synthetic lipid emulsions of chylomicron (TG1) and low density lipoprotein (TG2) diameter, consisting of triacylglycerol and phosphatidylcholine, were incubated with rat serum, whole blood, plasma, and postheparin plasma in the presence or absence of divalent cations. The lipid and apoprotein composition of the reisolated Sf > 400 particles was examined by high temperature gas chromatography and sodium dodecyl sulfate – glycerol polyacrylamide gel electrophoresis, respectively. It was found that apoproteins C, E, H, and A-I were associated with TG1 after incubation with whole blood + EDTA, EDTA–plasma, or EDTA–postheparin plasma. Significant amounts of unidentified apoproteins with molecular weights greater than 45 000 were also associated with these particles. Apoprotein E, apoprotein A-I, and a 51 000 dalton apoprotein were associated with the Sf > 400 fraction of TG2 recovered after incubation under the same conditions. The apoprotein profiles were indistinguishable from those previously reported for the corresponding Sf > 400 fraction recovered after intravenous infusion of TG1 and TG2. In the presence of Ca2+ and Mg2+ either in serum or in plasma and postheparin plasma, two additional proteins were recovered in the Sf > 400 fractions of TG1 and TG2. These apoproteins were of molecular weight 28 000 and 48 000 and had not been previously reported as components of plasma lipoproteins.
Activation and decay of the rat mast cells and its relationship to calcium uptake
Authors: Lewis Rubina , Dhanani Nusrat , Ranadive N. S.
Published: December 2009

Rat mast cells, stimulated for histamine release by compound 48/80 or lysosomal cationic protein, take up 45Ca2+ from the extracellular fluid. This uptake is inhibited by diisopropyl fluorophosphate, phenylmethylsulfonyl fluoride, and the inhibitors of energy metabolism. It was seen previously, when the release process is divided into two stages by activating the cells at 0 °C, the uptake of 45Ca2+ occurs during the release stage of the reaction. In the present studies, it was found that when cells activated at low temperatures were allowed to stand at 10 °C in the presence of 45Ca2+, the uptake of radioactive calcium increased in the first 15 min and then decreased to the levels of unstimulated cells. On the other hand, the release of histamine from the activated cells upon warming to 37 °C progressively decreased with an increase in time at 10 °C. These results suggest that during the decay of the active state the levels of intracellular exchangeable calcium pool are increased. For 45Ca2+ to be pumped out after the decay, there has to be net gain in intracellular calcium concentration during the first 15 min at 10 °C. The increase in membrane permeability to calcium appears to be due to the activation of a transient event.
Cellular distribution of enzymes involved in phosphatidylcholine synthesis in developing rat lung
Authors: Chan Frank , Harding Paul G. R. , Wong Tanya , Fellows G. Frazer , Possmayer Fred
Published: December 2009

The incorporation of radioactive choline into phosphatidylcholine and disaturated phosphatidylcholine in rat lung slices increased markedly before term and peaked after birth. The specific activity of cholinephosphate cytidylyltransferase in the microsomal fraction increased before birth but fell after delivery. The specific activity of this enzyme in the cytosol showed a marked increase at birth. The developmental profile for the total cytosolic activity per gram lung was similar to the pattern observed with choline incorporation. Although the specific activity of cholinephosphotransferase in the whole homogenate remained relatively constant throughout pulmonary maturation, there was a marked increase in the specific activity of this enzyme in the microsomal fraction at term. Similar findings were obtained with the microsomal marker NADPH-cytochrome c reductase. The basis of this disparity in specific activity profiles is being investigated further. The specific activity of lysophosphatidylcholine: lysophosphatidylcholine transacylase in rat lung homogenates increased during gestation but rose a further 10-fold between day 3 after birth and the adult. The specific activity of lysophosphatidylcholine: palmitoyl-CoA acyltransferase remained relatively constant throughout development. At term, the specific activity of the acylation enzyme was 10- to 15-fold greater than the specific activity of the transacylation enzyme. These observations are consistent with previous studies indicating that the accumulation of phosphatidylcholine and dipalmitoyl phosphatidylcholine during the perinatal period may be due to alterations in the activity of cholinephosphate cytidylyltransferase. Cholinephosphotransferase could also play a regulatory role. The formation of dipalmitoyl phosphatidylcholine appears to occur via the acylation, rather than the transacylation pathway.
Na+-independent exchange of amino acids in Ehrlich cells
Authors: Johnstone R. M.
Published: December 2009

Many hydrophilic amino acids are transported via exchange by the Na+-independent L system in the Ehrlich cells. However, this exchange is measurable only at relative high concentrations of the small hydrophilic amino acids. Whereas leucine saturated this transport system at 0.2 mM, with threonine, serine, or alanine the system was below saturation at 30 mM. All amino acids capable of exchanging showed similar EA values ([Formula: see text], 1 cal = 4.1868 J) and maximum velocities. Depending on the temperature, the apparent Km values for different amino acids differed by one or two orders of magnitude. These data suggest that for the small hydrophilic amino acids, the relatively slow rate of transport is due to the unfavorable Km values.
The relationship of cardiolipin biosynthesis to mitochondrial protein synthesis in Tetrahymena pyriformis
Authors: Hemmingsen Sean M. , Querengesser Laura , Young Paul G.
Published: December 2009

The synthesis of cardiolipin has been investigated following the inhibition of mitochondrial protein synthesis with chloramphenicol. Quantitative measurements of the amount of cardiolipin in the cell during treatment with chloramphenicol as well as pulse-labelling studies using labelled acetate were carried out. The results show that while whole cell phospholipid biosynthesis is depressed by the treatment (probably a reflection of a general cessation of growth), there is no sign of any preferential effect on cardiolipin synthesis. The data also show that as cells are reduced in size as they approach stationary phase there is a six- to seven-fold loss of total cellular phospholipids; however, the amount of cardiolipin is only reduced by four- to five-fold. There is a preferential conservation of cardiolipin as stationary phase is approached with the mole percent cardiolipin phosphorus in the cell rising from 5–7% to 10–12%.
L-Glutamine alteration of gene expression, not of polyphosphate and calcium metabolism, is a key event in arresting fungal sporulation
Authors: LéJohn Herb B.
Published: December 2009

Vegetatively growing cells of the coenocytic freshwater mould Achlya developed asexual sporangia and sporulated within 6 h of postransfer to a nutrient-free (starvation) medium. Sporangial development was arrested by the addition of L-glutamine to starving cells. During starvation (minus glutamine), three polyphosphate substances accumulated intracellularly, ATP was rapidly depleted, and a protein of molecular weight 42 000 (presumed to be actin) was actively synthesized, whereas synthesis of the most abundant detergent-soluble protein of molecular weight 83 000 (p83) ceased. In the presence of glutamine, starving cells used up the polyphosphates faster than they were formed. ATP depletion was delayed, cell calcium (Ca) exited rapidly, and synthesis of actin diminished while p83 synthesis continued unabated. Several pyrimidine analogues, including 5-diazouracil (which inhibited pyridimide nucleotide biosynthesis), and inorganic phosphate prevented Ca exit from glutamine-supplemented starving cells. The pyrimidine analogues delayed but did not inhibit sporangial development; however, they did not overcome glutamine suppression of sporangial development. Vegetatively growing and starving cells displayed significantly different protein synthesis patterns (monitored by polyacrylamide gel electrophoresis) but, when glutamine was added, it changed the protein synthesis pattern of starving cells to a form typical of vegetatively growing cells. Glutamine withdrawal reversed the effect and the cells differentiated. Pyrimidine analogues and inorganic phosphate did not alter the protein synthesis patterns of starving cells in the presence and absence of glutamine. The conclusion is that glutamine inhibition of sporangial development may be linked to its ability to subvert starving cell metabolism by making it vegetativelike.
Purification and characterization of a membrane-associated testosterone-binding protein from Pseudomonas testosteroni
Authors: Francis Mike McD. , Watanabe Mamoru
Published: December 2009

A steroid-binding protein, identified in the supernatant generated when membrane vesicles of Pseudomonas testosteroni are produced and harvested by centrifugation, has been purified 49-fold to homogeneity. It has a molecular weight of 30 000 – 35 000 and it specifically binds the C19 steroids dihydrotestosterone, testosterone, and androstenedione. It is a basic protein with an isoelectric point at pH 7.3. Binding of testosterone exhibited normal saturation kinetics with an affinity constant, Kd, of 3.9 × 10−8 M. Binding was inhibited by divalent cations, but the sulfhydryl reagents dithiothreitol and mercaptoethanol did not affect activity. It is suggested that this and other membrane-associated steroid-binding proteins concentrate the steroid at the membrane surface before it is transported into the cytoplasm of P. testosteroni.
Effect of high fat and high sucrose feeding on lipogenesis by isolated rat intestinal cells
Authors: Wilson A. C. , Goldstein R. C. , Conn A. R. , Kuo P. T.
Published: December 2009

Lipid synthesis was studied in intestinal mucosal cells isolated from rats fed a high fat or a high sucrose diet. The cells actively incorporated 14C(1)-labeled free fatty acids into glycerolipids([1-14C]acetate was utilized for both fatty acid and cholesterol synthesis), while [14C(U)]glucose label was found in cholesterol and in the glycerol moiety of glycerolipids, but not in fatty acids. Sucrose feeding resulted in increased acetate incorporation into cholesterol, but not into fatty acids while the high fat diet markedly depressed the incorporation of acetate. In contrast, fat feeding increased both glucose and fatty acid incorporation into glycerolipids, as well as glucose incorporation into cholesterol. Using the incorporation of glucose into lipid glycerol as an estimate of the phosphatidic acid pathway, it was found that this pathway was stimulated by both fat and carbohydrate feeding. The results suggest that differences in the regulation of cholesterol and glycerolipid synthesis in the intestine compared with adipose tissue and liver may relate to the role of intestine in synthesizing lipoproteins for lipid transport.