bluuebunny/crossref_metadata_2025 huggingface dataset:
Macrocystic serous cystadenocarcinoma of the pancreas: the first report of a new pattern of pancreatic carcinoma
Authors: Gupta R , Dinda A K , Singh M K , Misra M C
Published: February 2008

Cystic pancreatic neoplasms are rare and include mucinous and microcystic cystadenoma (carcinomas) and the recently described macrocystic adenoma. Their accurate diagnosis is difficult by radiology, and histopathology remains the modality of choice. The case of a 42-year-old woman presenting with a gradually enlarging abdominal mass is reported. Imaging studies revealed a large unilocular cystic lesion in the pancreas. An exploratory laparotomy was done with excision of the cyst along with pancreas. Numerous microscopic sections revealed a serous neoplasm with atypical nuclear features and focal invasion of the cyst wall. A final pathological diagnosis of macrocystic serous cystadenocarcinoma of the pancreas was made. The patient has been doing well two years after surgery. This is the first case of a macrocystic serous cystadenocarcinoma of the pancreas, highlighting the need for extensive sampling of all cystic lesions of the pancreas in order to reach a correct diagnosis.
A 32-country comparison of tobacco smoke derived particle levels in indoor public places
Authors: Hyland A , Travers M J , Dresler C , Higbee C , Cummings K M
Published: February 2008

Objective:

To compare tobacco smoke-derived particulate levels in transportation and hospitality venues with and without smoking in 32 countries using a standardised measurement protocol.

Methods:

The TSI SidePak AM510 Personal Aerosol Monitor was used to measure the concentration of particulate matter less than 2.5 microns in diameter (PM2.5) in 1822 bars, restaurants, retail outlets, airports and other workplaces in 32 geographically dispersed countries between 2003 and 2007.

Results:

Geometric mean PM2.5levels were highest in Syria (372 μg/m3), Romania (366 μg/m3) and Lebanon (346 μg/m3), while they were lowest in the three countries that have nationwide laws prohibiting smoking in indoor public places (Ireland at 22 μg/m3, Uruguay at 18 μg/m3 and New Zealand at 8 μg/m3). On average, the PM2.5levels in places where smoking was observed was 8.9 times greater (95 CI 8.0 to 10) than levels in places where smoking was not observed.

Conclusions:

Levels of indoor fine particle air pollution in places where smoking is observed are typically greater than levels that the World Health Organization and US Environmental Protection Agency have concluded are harmful to human health.
A difference that makes a difference: young adult smokers’ accounts of cigarette brands and package design
Authors: Scheffels J
Published: February 2008

Objective:

To explore young adult smokers’ construction of meaning and identity in accounts of cigarette brands and cigarette package design, and the processes by which positive associations with a brand may be reinforced and sustained.

Methods:

Qualitative in-depth interviews with 21 smokers aged 18–23 in Norway, where advertising for tobacco has been banned since 1975.

Results:

Cigarette brand and cigarette package design appear as an integrated part of young smokers’ constructions of smoker identities, enabling the communication of personal characteristics, social identity and positions in hierarchies of status.

Conclusion:

Through branding and package design tobacco companies appear to be able to promote their products in a country where advertising is banned, by means of similar principles that make advertising effective: by creating preferences, differentiation and identification.
An examination of trends in amount and type of cigarette advertising and sales promotions in California stores, 2002–2005
Authors: Feighery E C , Schleicher N C , Cruz T Boley , Unger J B
Published: February 2008

Background:

Cigarette companies spend more of their marketing dollars in stores than in any other venue. In 2005, they spent 88% of a total of $13.1 billion to advertise and promote product sales in stores.

Aim:

The purposes of this study were to identify how the amount and types of cigarette advertising and sales promotions have changed in stores in California between 2002 and 2005, and to assess neighbourhood influences on cigarette marketing in stores.

Methods:

Four observational assessments of cigarette advertising were conducted in approximately 600 California stores that sold cigarettes from 2002 to 2005. Trained observers collected data on the amount and type of cigarette advertising, including signs, product shelving and displays and functional items, and presence of sales promotions on these items. Longitudinal analyses were performed to estimate trends over time and identify correlates of change in the amount and type of tobacco advertising.

Results:

The mean number of cigarette advertisements per store increased over time from 22.7 to 24.9. The percentage of stores with at least one advert for a sales promotion increased from 68% to 80%. The amount of advertising and proportion of stores with sales promotions increased more rapidly in stores situated in neighbourhoods with a higher proportion of African–Americans.

Conclusion:

The results indicate increasing use of stores to market and promote cigarette sales. Further, these increases are disproportionately accelerating in neighbourhoods with more African–Americans. Legislative strategies should be pursued to control the marketing of tobacco products and promotional strategies used to reduce prices in stores.
Unusual growth patterns in short shoots of Pinus radiata
Authors: Harris J. M. , Singh A. P.
Published: February 2008

Short shoots and the needles that they bear usually persist for about 3 years on stems and branches of Pinus radiata D. Don. As the main axis thickens with secondary growth, short shoots may elongate by four times their original length, during which process xylem elements become embedded in the stem as "needle trances," although the external shoots appear to remain unchanged. This report describes how elongation in both xylem and phloem results from the insertion of new vascular elements derived from marginal cells of radial parenchyma bands. There was no evidence that the apical meristem contributes to this growth. Possible mechanisms for elongation of pith and cortex are also described.
Wettsteinina
Authors: Shoemaker R. A. , Babcock C. E.
Published: February 2008

Twenty-three species accepted in Wettsteinina Höhnel are described and illustrated. Thirteen of these are new: W. arctica, W. barrae, W. bupleuri, W. Candida, W. douglasii, W. duplex, W. junci, W. kashmirensis, W. kobresiae, W. luzulae, W. magnifica, W. oreophila, and W. savilei. Details are given on 11 excluded species: Didymella anomala (Ell. & Ev.) n.comb. (= Wettsteinina anomala (Ell. & Ev.) Barr), Dothiora ellisii (Barr) n.comb. (= Wettsteinina ellisii Barr), Gnomonia sabalicola Earle (= Wettsteinina sabalicola (Earle) Barr), Kriegeriella mediterranea (E. Müller) von Arx & Müller (= Wettsteinina mediterranea E. Müller), Lophiostoma herbarum (Wehmeyer) n.comb. (= Eriosphaeria herbarum Wehmeyer), Lophiostoma sieversiae Peck (= Wettsteinina sieversiae (Peck) Barr = Wettsteinina andromedae (Auersw.) Barr. var. cassiopes (Dearn. & House ex Barr) Barr = Phaeospora cassiopes Dearness & House, ex Barr), Lophiostoma species 1, Lophiostoma species 2 (= Wettsteinina niesslii E. Müller), Pleospora cytisi Fuckel (= Wettsteinina ambigua Petrak), Wettsteinina niesslii E. Müller sensu Barr non Niessl, and Wettsteinina yuccaegena Barr. Some others are excluded but not redescribed. Cultures of W. gigaspora, the type species, indicated that the fungus is homothallic and does not form an anamorph in culture and that the centrum is of the Pleospora type. The families Pseudosphaeriaceae Höhnel and Wettsteininaceae Locquin nom.illeg. are synonymized with Pleosporaceae Nitschke.
Taxonomic relationships among the toxigenic speciesFusarium acuminatum,Fusarium sporotrichioidesandFusarium tricinctumby isozyme analysis and RAPD assay
Authors: Altomare Claudio , Logrieco Antonio , Petrini Orlando , Bottalico Antonio
Published: February 2008

Isozyme and random amplified polymorphic DNA (RAPD) analyses have been used in combination with numerical taxonomy to study the taxonomic relationships among the toxigenic species Fusarium acuminatum Ellis & Everh. sensu Gordon (subsp. acuminatum and subsp. armeniacum), Fusarium sporotrichioides Sherb. and Fusarium tricinctum (Corda) Sacc. Eight enzymes, selected among 23 enzyme systems tested initially for activity, resolution, and consistent formation of bands, were used for isozyme analysis of 75 strains. Both cluster analysis grouping by average linkage method and correspondence analysis of the isozyme data set resulted in an arrangement of the four taxa inconsistent with their classical taxonomic classification in the Fusarium sections Gibbosum and Sporotrichiella. Isolates of F. acuminatum subsp. acuminatum were more closely related to F. tricinctum than to F. acuminatum subsp. armeniacum. Correspondingly, the F. acuminatum subsp. armeniacum group was closer to F. sporotrichioides than to F. acuminatum subsp. acuminatum. Twenty-seven strains of the four taxa, representative of the variability found by isozyme analysis, were studied using a RAPD analysis with five different decamer primers. All the primers produced polymorphic amplification patterns with taxon-specific bands, in addition to individual-specific bands. Correspondence analysis of the RAPDs distinguished four compact groups corresponding to the four taxa studied. These data support the separation of the varieties of F. acuminatum into two different species, and suggest a revision of the Fusarium sections Gibbosum and Sporotrichiella may be necessary. Key words: Fusarium, isozymes, RAPDs, numerical taxonomy, mycotoxins.
Asymmetry in the trunk vertebrae of Lota lota lacustris (Walbaum)
Authors: Beamish R. J. , Scott W. B.
Published: February 2008

The trunk vertebrae of Lota lota lacustris are shown to be asymmetrical, having the cavity accommodating the dorsal aorta displaced to the right in the region adjacent to the swim bladder.
Influence of light on early development and meristic characters in the rainbow trout, Salmo gairdneri Richardson
Authors: MacCrimmon H. R. , Kwain Wen-Hwa
Published: February 2008

Initial mortality of newly fertilized rainbow trout eggs incubated in artificial light increased with intensity. The mortality among eyed eggs exposed to the same set of conditions was comparatively low regardless of intensity. Mortality, time to hatch, metabolic rate, and the number of vertebrae formed correlated positively with visible light intensity but only during the pre-eyed stage of incubation. By contrast, the numbers of dorsal and anal fin rays were affected by light intensity during the posteyed incubation period, the greatest number of rays on these fins occurring in fish incubated at light intensity of 10 lux. The numbers of pectoral and pelvic fin rays were constant at all test light intensities. Further research is imperative if the importance of light as an environmental factor in the early development of fish is to be understood.
Incidence of coccidia in California quail (Lophortyx californicus) from the Okanagan Valley, British Columbia
Authors: Liburd Eugene M.
Published: February 2008

A survey of the incidence of coccidia in California quail (Lophortyx californicus) in the Okanagan Valley of southcentral British Columbia was conducted in the summers of 1965 and 1966. Seventy-three percent of 85 quail were infected with oocysts of Eimeria (Protozoa: Eimeriidae). The incidence of infection was higher in the adult (81%) and juvenile (79%) quail than in the immatures (40%). The incidence of infection seems to be correlated with the breeding phenology of the quail. The intensity of infection was higher in the immatures and juveniles than in the adults. No significant differences occurred in the incidence of infection between the sexes and the four study areas. There were monthly variations, with the lowest incidence occurring in June and the highest in August. No mortality or morbidity caused by coccidiosis was observed.
The microscopic and submicroscopic structure of the tunic of two ascidians, Boltenia and Molgula
Authors: Mishra A. K. , Colvin J. Ross
Published: February 2008

The structure of the tunic of two ascidians, Boltenia ovifera and Molgula griffithisii, was investigated by optical microscopy, X-ray diffraction, and electron microscopy.The outer surface of the tunic of Molgula consisted of a single layer of nucleated cells, with numerous protrusions 0.5–1.0 mm long. Inside this layer of cells, the cellulose microfibrils, which are a major component of the tunic, were randomly oriented within the plane of the tunic. No inner cellular layer was observable.The tunic of Boltenia had numerous, pointed spines on the outer surface but no cellular organization within the tunic was apparent. The spines were composed of parallel microfibrils (perhaps cellulose) oriented axially. The microfibrils of the spines were more densely packed and well oriented at the rim of the spines. In general, the arrangement of the cellulose microfibrils within the tunic was random within the plane of the tunic although there were some areas displaying optical birefringence and orientation of microfibrils.The observations are consistent with present knowledge of the mechanism of formation of cellulose microfibrils in green plants and bacteria but throw little light on the mechanism of morphogenesis of the tunics themselves.
The comparative life histories of three Cumacea (Crustacea): Cumopsis goodsiri (Van Beneden), Iphinöe trispinosa (Goodsir), and Pseudocuma longicornis (Bate)
Authors: Corey S.
Published: February 2008

Comparative studies are described of the life histories and gonadal development of three sand-dwelling cumaceans from Kames Bay, Isle of Cumbrae, Scotland. Cumopsis goodsiri, an intertidal species, and Iphinöe trispinosa, a sublittoral species, produce two generations per year. An overwintering generation produces young during May and June which mature rapidly and produce young forming the next overwintering generation in August. Pseudocuma longicornis, also a sublittoral species, breeds continuously throughout the year.
The ultrastructure of the rostral sensory organs of the water bug, Cenocorixa bifida (Hungerford) (Hemiptera)
Authors: Lo S. E. , Acton A. B.
Published: February 2008

There are six transverse bands of sensory organs on the dorsal part of the labium of the water bug Cenocorixa bifida. Though phase contrast microscopy of the intact labium shows that each of these bands is made up of from four to six rows of sensilla, among which there are clearly several types of end structure, all appear to have the same ultrastructure below the surface of the cuticle.It was found by electron microscopy that each sense organ is composed of a single bipolar neuron, which, together with its sheath cell, forms a sensory unit. The dendrite of the neuron has a root system, two basal bodies, and an axial filament complex. It runs through the cuticle to the peg at the surface. Owing to difficulty in sectioning, no details of the terminal pegs were obtained, though they have a definite lumen at their base.The tips of the largest sensilla, but no others, were permeable to a solution of crystal violet. This permeability, their ultrastructure, and their location near the mouth and close to numerous obvious mechanoreceptors with long bristles, make it possible that these organs are chemoreceptors. Only electrophysiological studies can confirm this. The function of the rest of the sensilla, which form the majority, is unknown.
Geographic distribution, species displacement, and niche overlap for lake trout and bull trout in mountain lakes
Authors: Donald David B. , Alger David J.
Published: February 2008

Indigenous lacustrine populations of bull trout (Salvelinus confluentus) and lake trout (S. namaycush) are spatially separated within the southern part of the zone of distributional overlap (northern Montana, southwestern Alberta, and east-central British Columbia). In this area, lake trout occurred primarily in mountain lakes of 1032–1500 m elevation, while bull trout were found primarily in lakes between 1500 and 2200 m. Introductions of lake trout in the twentieth century and data obtained from beyond the study area indicated that both fishes can establish significant allopatric populations (more than 5% of the catch) in large, deep lakes (>8 ha in area and >8 m deep) over a wide elevation range. We tested the hypothesis that lake trout displace or exclude bull trout from lakes by determining the outcome of introductions of lake trout into two lakes that supported indigenous bull trout. Lake trout were introduced into Bow Lake in 1964, and by 1992 the bull trout population was decimated there and in another lake (Hector) situated 15 km downstream. Thus, lake trout can displace bull trout and may prevent bull trout from becoming established in certain low-elevation lakes. Population age-structure analyses also suggest that lake trout adversely affected bull trout. Bull trout populations in sympatry with lake trout, including the one extirpated from Hector Lake, had few old fish (18% were more than 5 years old; N = 40 fish from three lakes) compared with allopatric populations (49% were more than 5 years old; N = 235 fish from seven lakes). Niche overlap and the potential for competition between the two char species were substantial. In lakes with trophic structure ranging from simple to complex, bull trout and lake trout fed on similar foods and had similar ecological efficiencies (growth rates). Predation by lake trout on bull trout was not documented during the study.
Female convict cichlids adjust gonadal investment in current reproduction in response to relative risk of brood predation
Authors: Wisenden Brian D.
Published: February 2008

Parental care theory predicts that investment in current reproduction should be increased when the prospects of success in current reproductive effort are relatively high, and reduced when they are poor relative to expected success from future reproductive effort. A number of studies have shown that levels of postspawning parental investment (brood defence, parents' willingness to risk predation) increase when the brood is augmented. However, few studies have shown a change in pre-spawning (gonadal) investment in response to indirect indicators of reproductive success, such as nest site quality. Convict cichlids (Cichlasoma nigrofasciatum) are small freshwater fish that have biparental care of their young. Pairs of convict cichlids were required to spawn in either "risky" or "secure" spawning caves in the presence of potential egg predators. As predicted by parental care theory, females laid significantly more eggs in secure spawning caves than in risky spawning caves. The ability of this iteroparous fish to adjust gonadal investment in this manner would serve to optimize the use of its resources under varying environmental conditions and ultimately allow it to realize maximize lifetime reproductive success.
The winter diet of thick-billed murres, Uria lomvia, in western Greenland, 1988–1989
Authors: Falk Knud , Durinck Jan
Published: February 2008

The diet of thick-billed murres (Uria lomvia) wintering in coastal western Greenland was studied by analyzing the stomach contents of 202 birds supplied by local hunters in four regions, from October 1988 to March 1989. Fish and crustaceans were present in 68 and 71% (frequency of occurrence), respectively, of all stomachs containing prey remains (n = 195). Fish made up 81% wet weight, and crustaceans most of the remaining 19%, except for < 1% squid (Gonatus sp.) and polychaetes (Nereis sp.). Capelin (Mallotus villosus) was the dominant prey species (61% wet weight), followed by Thysanoessa spp. (17%), Parathemisto spp. (1%), and Meganyctiphanes norvegica (1%). Euphausiids were the most abundant crustaceans (95% wet weight of all crustaceans), except in October, when hyperid amphipods were dominant (89%). Crustaceans were important in the murres' diet only in the northern part of the survey area; birds in the southern part preyed almost exclusively upon capelin. Most birds were in good body condition (based on the amount of body fat), but murres from the southern area had a slightly higher mean fat index than those from the northern area (7.19 vs. 5.35). We suggest that differences in body condition may be related to the higher proportion of fish, which is of higher caloric value, in the diet of murres in the southern area.
Phylogeny of the Rhabdocoela (Platyhelminthes): a working hypothesis
Authors: Jondelius Ulf , Thollesson Mikael
Published: February 2008

An attempt is made to resolve contradictions in recent studies of the phylogeny of the Rhabdocoela (including the major parasitic flatworm groups), with a hypothesis based on parsimony analysis of characters determined at both the light microscopic and the ultrastructural level. The rhabdocoel subtaxa "Dalyellioida" and "Typhloplanoida" are shown to be non-monophyletic. The taxon Endoaxonemata, comprising the last common ancestor of the Neodermata, Pterastericolidae, Fecampiidae, and Acholadidae and all its descendants is named as a result of the study. Crustaceans are proposed as the primitive hosts of this group. Separate islands of equally parsimonious trees were encountered in some of the parsimony analyses performed. Failure to find all such islands may cause misinterpretation of the results. The impact on the results of different methods of rooting cladograms and different heuristic search strategies implemented in the PAUP software are discussed.
Multiple paternity in clutches of snapping turtles (Chelydra serpentina) detected using DNA fingerprints
Authors: Galbraith David A. , White Brad N. , Brooks Ronald J. , Boag Peter T.
Published: February 2008

Female common snapping turtles (Chelydra serpentina) are capable of storing viable sperm for at least several months and are likely to be inseminated by more than one male. Consequently, we tested the hypothesis that multiple paternity occurred within individual clutches of three common snapping turtles from Algonquin Provincial Park, Ontario, Canada, by examining DNA fingerprints. Positive evidence of multiple paternity was detected among samples of offspring from two of the three clutches. In these clutches, the distributions of both paternal DNA fingerprint bands and band-sharing coefficients deviated from those expected under the assumption of a single father, suggesting that paternity was distributed between two or more males in each clutch. Multiple paternity and the ability of females to store sperm make turtles good animals in which to study sperm competition. The mating systems and life-history features of turtles should be studied with the consequences of sperm storage and multiple paternity in mind.
Sexual dimorphism in thick-billed murres, Uria lomvia
Authors: Stewart Donald T.
Published: February 2008

The pattern of sexual dimorphism in thick-billed murres, Uria lomvia, from the Lancaster Sound – Jones Sound region, Northwest Territories, was examined for weight and 21 skeletal characters. Univariate statistics (Bonferroni-corrected t-tests) indicated that males were significantly larger than females in 6 bill and skull characters. Multivariate statistics also indicated that males had larger bills and skulls than females (based on canonical discriminant analysis), but males were not larger than females in overall body size (as defined by the first principal-components axis). The direction and magnitude of dimorphism were consistent with a hypothesis based on sexual selection as the driving force. In particular, large bill and skull sizes in males are consistent with agonistic behaviours associated with male–male competition for breeding sites and mate guarding.
Allométrie de la masse du squelette chez des amphibiens anoures
Authors: Leclair Jr. Raymond , Lamontagne Chantale , Aubin Antoine
Published: February 2008

To verify the functional hypotheses that link, in vertebrates, the skeletal mass (Ms) to the total body mass (Mt), the skeletons of 75 adult specimens of anuran amphibians (Mt = 5–400 g) belonging to 7 species, aquatic, semiaquatic, or terrestrial (5 Rana, Bufo americanus, and Xenopus laevis), have been extracted by enzymatic maceration, and air-dried. Covariance analyses show significant differences in position, but not in slope, between the anuran species in the specific allometric relationships [Formula: see text]. A Spearman rank test indicated a highly significant relationship between the regression-line position and the level of species infeodation to the aquatic habitat. The relationship is more evident for the Ranids. The relative mass of the skeleton in terrestrial species (e.g., R. sylvatica: 4.4%) can be twice that of aquatic species (e.g., R. septentrionalis: 2.3%). For the 75 anuran specimens, the calculated allometric equation, [Formula: see text], is very close to the one already established for teleost fish. When R. septentrionalis is excluded, the allometric coefficient becomes significantly inferior to unity (b = 0.928). It is concluded that the relative mass of the skeleton is linked with individual and species body size but that the life mode has a preponderant influence. A model that takes into account intra- and inter-specific variations in body mass is developed to predict the skeletal mass of an anuran.
Comparison of parental behavior in male and female prairie voles (Microtus ochrogaster)
Authors: Solomon Nancy G.
Published: February 2008

A comparison of male and female parental investment patterns is needed before predictions can be generated from parental investment theory. One aspect of parental investment is parental care, therefore behavioral observations were conducted to compare the parental behavior of male and female prairie voles. Females brooded pups more frequently than did males during the first week of pup life and, in the absence of their mates in the nest, brooded pups more frequently throughout the preseparation period (between birth and separation from parents on day 20). Females also licked pups more frequently than did males during the entire preseparation period. Conversely, males spent more time outside the nest throughout the preseparation period. There were no differences between the sexes in the proportion of time spent in indirect parental behaviors such as nest building, food caching, or runway maintenance. These differences in direct parental care combined with a female's energetic investment in gestation and lactation result in greater total parental investment for female than for male prairie voles.
ANHARMONIC OSCILLATOR ENERGIES BY THE ASYMPTOTIC ITERATION METHOD
Authors: CIFTCI HAKAN
Published: February 2008

In a previous paper (J. Phys. A36, 11807 (2003)), the "asymptotic iteration method" was introduced and developed for solving second-order homogeneous linear differential equations. In this paper we use the method to study the quantum quartic anharmonic oscillator problem. We obtain accurate eigenvalues for both small and large coupling parameters.
VACUUM BIREFRINGENCE CAUSED BY ARBITRARY SPIN PARTICLES
Authors: KRUGLOV S. I.
Published: February 2008

We study the propagation of a linearly polarized laser beam in the external transverse magnetic field taking into consideration the vacuum polarization by arbitrary spin particles. Induced ellipticity of the beam is evaluated using the effective Lagrangian. With the help of the PVLAS experimental data, we obtain bounds on masses of charged higher spin particles contributed to ellipticity.
A SERVICE-ORIENTED APPROACH FOR INTEGRATING HETEROGENEOUS SPATIAL DATA SOURCES REALIZATION OF A VIRTUAL GEO-DATA REPOSITORY
Authors: PAUL MANOJ , GHOSH S. K.
Published: February 2008

Searching and accessing geospatial information in the open and distributed environments of geospatial information systems poses several challenges due to the heterogeneity in geospatial data. Geospatial data is highly heterogeneous — both at the syntactic and semantic level. The requirement for an integration architecture for seamless access of geospatial data has been raised over the past decades. The paper proposes a service-based model for geospatial integration where each geospatial data provider is interfaced on the web as services. The interface for these services has been described with Open Geospatial Consortium (OGC) specified service standards. Catalog service provides service descriptions for the services to be discovered. The semantic of each service description is captured in the form of ontology. The similarity assessment method of request service with candidate services proposed in this paper is aimed at resolving the heterogeneity in semantics of locational terms of service descriptions. In a way, we have proposed an architecture for enterprise geographic information system (E-GIS), which is an organization-wide approach to GIS integration, operation, and management. A query processing mechanism for accessing geospatial information in the service-based distributed environment has also been discussed with the help of a case study.
The APOBEC3 Cytidine Deaminases: An Innate Defensive Network Opposing Exogenous Retroviruses and Endogenous Retroelements
Authors: Chiu Ya-Lin , Greene Warner C.
Published: February 2008

All retroviruses, including HIV-1, display species-specific patterns of infection. The impaired growth of these retroviruses in foreign and sometimes even in their natural hosts often stems from the action of potent host-encoded “viral restriction factors” that form important protective components of the innate immune system. The discovery of APOBEC3G and related cytidine deaminases as one class of host restriction factors and of the action of HIV-1 Vif as a specific APOBEC3G antagonist have stimulated intense scientific interest. This Vif-APOBEC3G axis now forms a very attractive target for development of an entirely new class of anti-HIV drugs. In this review, we summarize current understanding of the mechanism of action of the APOBEC3 family of enzymes, their intriguing regulation within cells, the impact of these enzymes on viral evolution and disease progression, and their roles in controlling not only the replication of exogenous retroviruses but also the retrotransposition of endogenous retroelements.
Evolutionarily Conserved Amino Acids That Control TCR-MHC Interaction
Authors: Marrack Philippa , Scott-Browne James P. , Dai Shaodong , Gapin Laurent , Kappler John W.
Published: February 2008

The rules for the conserved reaction of αβ T cell receptors (TCRs) with major histocompatibility complex (MHC) proteins plus peptides are poorly understood, probably because thymocytes bearing TCRs with the strongest MHC reactivity are lost by negative selection. Thus, only TCRs with an attenuated ability to react with MHC appear on mature T cells. Also, the interaction sites between TCRs and MHC may be inherently flexible and hence difficult to spot. We reevaluated contacts between TCRs and MHC in the solved structures of their complexes with these points in mind. Relatively conserved amino acids in the TCR complementarity-determining regions (CDR) 1 and CDR2 are often used to bind exposed areas of the MHC α-helices. These areas are exposed because of small amino acids that allow somewhat flexible binding of the TCRs. The TCR amino acids involved are specific to families of variable (V) regions and to some extent different rules may govern the recognition of MHCI versus MHCII.
Thyroid-stimulating hormone increases active transport of perchlorate into thyroid cells
Authors: Tran Neil , Valentín-Blasini Liza , Blount Benjamin C. , McCuistion Caroline Gibbs , Fenton Mike S. , Gin Eric , Salem Andrew , Hershman Jerome M.
Published: February 2008

Perchlorate blocks thyroidal iodide transport in a dose-dependent manner. The human sodium/iodide symporter (NIS) has a 30-fold higher affinity for perchlorate than for iodide. However, active transport of perchlorate into thyroid cells has not previously been demonstrated by direct measurement techniques. To demonstrate intracellular perchlorate accumulation, we incubated NIS-expressing FRTL-5 rat thyroid cells in various concentrations of perchlorate, and we used a sensitive ion chromatography tandem mass spectrometry method to measure perchlorate accumulation in the cells. Perchlorate caused a dose-related inhibition of 125-iodide uptake at 1–10 μM. The perchlorate content from cell lysate was analyzed, showing a higher amount of perchlorate in cells that were incubated in medium with higher perchlorate concentration. Thyroid-stimulating hormone increased perchlorate uptake in a dose-related manner, thus supporting the hypothesis that perchlorate is actively transported into thyroid cells. Incubation with nonradiolabeled iodide led to a dose-related reduction of intracellular accumulation of perchlorate. To determine potential toxicity of perchlorate, the cells were incubated in 1 nM to 100 μM perchlorate and cell proliferation was measured. Even the highest concentration of perchlorate (100 μM) did not inhibit cell proliferation after 72 h of incubation. In conclusion, perchlorate is actively transported into thyroid cells and does not inhibit cell proliferation.
Role of TNF-α in ileum tight junction alteration in mouse model of restraint stress
Authors: Mazzon Emanuela , Cuzzocrea Salvatore
Published: February 2008

Restraint stress induces permeability changes in the small intestine, but little is known about the role of tumor necrosis factor (TNF)-α in the defects of the TJ function. In the present study, we used tumor necrosis factor-R1 knockout mice (TNF-α-R1KO) to understand the roles of TNF-α on ileum altered permeability function in models of immobilization stress. The genetic TNF-α inhibition significantly reduced the degree of 1) TNF-α production in ileum tissues; 2) the alteration of zonula occludens-1 (ZO-1), claudin-2, claudin-4, claudin-5, and β-catenin (immunohistochemistry); and 3) apoptosis (TUNEL staining, Bax, Bcl-2 expression). Taken together, our results demonstrate that inhibition of TNF-α reduces the tight junction permeability in the ileum tissues associated with immobilization stress, suggesting a possible role of TNF-α on ileum barrier dysfunction.
MicroRNomics: a newly emerging approach for disease biology
Authors: Zhang Chunxiang
Published: February 2008

Genomic evidence reveals that gene expression in humans is precisely controlled in cellular, tissue-type, temporal, and condition-specific manners. Completely understanding the regulatory mechanisms of gene expression is therefore one of the most important issues in genomic medicine. Surprisingly, recent analyses of the human and animal genomes have demonstrated that the majority of RNA transcripts are relatively small, noncoding RNAs (sncRNAs), rather than large, protein coding message RNAs (mRNAs). Moreover, these sncRNAs may represent a novel important layer of regulation for gene expression. The most important breakthrough in this new area is the discovery of microRNAs (miRNAs). miRNAs comprise a novel class of endogenous, small, noncoding RNAs that negatively regulate gene expression via degradation or translational inhibition of their target mRNAs. As a group, miRNAs may directly regulate ∼30% of the genes in the human genome. In keeping with the nomenclature of RNomics, which is to study sncRNAs on the genomic scale, “microRNomics” is coined here to describe a novel subdiscipline of genomics that studies the identification, expression, biogenesis, structure, regulation of expression, targets, and biological functions of miRNAs on the genomic scale. A growing body of exciting evidence suggests that miRNAs are important regulators of cell differentiation, proliferation/growth, mobility, and apoptosis. These miRNAs therefore play important roles in development and physiology. Consequently, dysregulation of miRNA function may lead to human diseases such as cancer, cardiovascular disease, liver disease, immune dysfunction, and metabolic disorders. microRNomics may be a newly emerging approach for human disease biology.
Structures and anisotropic thermal expansion of the α, β, γ, and δ polymorphs of Y2Si2O7
Authors: Dolan M. D. , Harlan B. , White J. S. , Hall M. , Misture S. T. , Bancheri S. C. , Bewlay B.
Published: February 2008

The α, β, γ, and δ polymorphs of Y2Si2O7 were synthesized using sol-gel and solid-state methods. The structures of the α and γ polymorphs were determined by identification of isostructural rare-earth disilicates, and the structures were refined using Rietveld analysis of X-ray powder diffraction data. The α polymorph crystallizes in space group P1, with a=6.5872(6) Å, b=6.6387(7) Å, c=12.032(1) Å, α=94.501(7)°, β=90.984(8)°, γ=91.771(7)°, and volume=524.16(9) Å3. The γ form is described by space group P21/c, a=4.68824(5) Å, b=10.84072(9) Å, c=5.58219(6) Å, and γ=96.0325(3)°. The anisotropic thermal expansion of each phase was measured using high temperature diffraction up to 1200 or 1400 °C, depending on the stability of the polymorph. The thermal expansion is highly anisotropic for all polymorphs, with the low-expansion direction normal to the long axis of the corner-shared SiO4 tetrahedra.
Powder diffraction data of a new compound Al0.35GdGe2
Authors: Zeng Lingmin , He Jiejun , Qin Pingli , Wei Xiangzhong
Published: February 2008

A new ternary compound Al0.35GdGe2 has been synthesized and studied by means of X-ray powder diffraction technique. The ternary compound Al0.35GdGe2 crystallizes in the orthorhombicwith the CeNiSi2 structure type (space group Cmcm, a=4.0874(2) Å, b=16.1499(5) Å,c=3.9372(1) Å, Z=4, and Dcalc=8.007 g/cm3).
Crystal structure, properties, and diffraction data of a new compound Dy5Co6Sn18
Authors: Chen Yeqing , He Bing , He Jiejun , He Wei , Zeng Lingmin , Nong Liangqin
Published: February 2008

A new ternary compound Dy5Co6Sn18 was synthesized and studied. The crystal structure of Dy5Co6Sn18 was determined using the Rietveld refinement method. The compound was found to crystallize in tetragonal space group I41/acd, Tb5Rh6Sn18-type structure, with a=13.5598(3) Å, c=7.1470(5) Å, Z=8, and Dcalc=8.789 g/cm3. Measurements of magnetic susceptibility and electrical resistivity on polycrystalline samples were also performed. The Curie–Weiss law was followed, with θp=−15.7 K and μeff=10.61μB. Dy5Co6Sn18 is a spin-glass with a freezing temperature of 6.5 K.
Thallium manganese sulfate hexahydrate, a missing Tutton’s salt, and a brief review of the entire family
Authors: Nalbandyan V. B.
Published: February 2008

A new Tutton’s salt Tl2[Mn(OH2)6](SO4)2 was grown from aqueous solutions and characterized by chemical analysis and X-ray powder diffraction. It was found to be monoclinic, space group P21/a, a=0.93276(6), b=1.25735(8), c=0.62407(4) nm, and β=106.310(3)°. It is unstable in warm air and dissolves incongruently. A comparison of unit cell volumes for all 37 Tutton sulfate phases found in ICDD’s PDF-2 database (86 entries) reveals a reasonable correlation with Shannon and Prewitt’s ionic radii [Acta Crystallogr. 25, 925–926 (1969)] and several deviations, most of them seeming to be erroneous entries.
Clopidogrel and Aspirin versus Aspirin Alone for the Prevention of Stroke in Patients with a History of Atrial Fibrillation: Subgroup Analysis of the CHARISMA Randomized Trial
Authors: Hart Robert G. , Bhatt Deepak L. , Hacke Werner , Fox Keith A.A. , Hankey Graeme J. , Berger Peter B. , Hu Tingfei , Topol Eric J.
Published: February 2008

Background: Aspirin offers modest reduction in stroke in patients with atrial fibrillation. Whether combination of aspirin with clopidogrel offers additional protection is unclear. Methods: Post-hoc subgroup analysis of 593 participants with a history of atrial fibrillation in the Clopidogrel for High Atherothrombotic Risk and Ischemic Stabilization, Management, and Avoidance (CHARISMA) randomized trial testing clopidogrel 75 mg per day plus aspirin (75–162 mg per day) vs. aspirin alone in patients with stable cardiovascular disease or multiple cardiovascular risk factors. Results: Mean patient age was 70 years, 78% were men, and hypertension, heart failure and diabetes were present in 78, 20 and 44%, respectively. During a median follow-up of 2.3 years, stroke (ischemic and hemorrhagic) occurred in 15 of 298 assigned to clopidogrel plus aspirin and in 14 of 285 given aspirin alone (hazard ratio, HR, 1.03, 95% CI 0.49–2.1). There was no difference in all-cause mortality (HR 1.1, 95% CI 0.6–1.9) or in the composite of stroke, myocardial infarction, or vascular death (HR = 1.2, 95% CI 0.7–2.0). Severe/fatal extracranial hemorrhage occurred in 6 patients with combination vs. 3 with aspirin alone. Conclusions: This post-hoc subgroup analysis does not support the use of this combination over aspirin alone in patients with a history of atrial fibrillation pending results of ongoing larger randomized trials.
Progression of Artificial Enamel Caries Lesions after Infiltration with Experimental Light Curing Resins
Authors: Meyer-Lueckel H. , Paris S.
Published: February 2008

The arrest of enamel caries lesions by infiltration with low-viscosity light curing resins might be a promising approach of microinvasive dentistry. However, no materials optimized for rapid lesion infiltration (‘infiltrants’) are commercially available today. The penetration coefficient (PC) of experimental resins has been shown to correlate with penetration speed and, therefore, might be an important feature of infiltrants. The aim of the present study was to evaluate the influence of PC and composition of experimental infiltrants on the progression of enamel lesions in a demineralizing environment. Artificial enamel lesions were prepared in a demineralization solution for 50 days and infiltrated with either one of twelve experimental infiltrants or a commercially available adhesive for 10, 22, and 40 s, respectively. Specimens were cut perpendicularly to the surface and one half of each specimen was exposed to a demineralizing solution for another 50 days, whereas the other half was used as baseline control. Lesion progression was analyzed using confocal microscopy (CLSM) and transversal microradiography (TMR). The square root of the product of PC and application time was negatively correlated with progression of lesion depth (CLSM: r = –0.741; TMR: r = –0.450). Therefore, infiltrants should preferably have high PCs to facilitate inhibition of lesion progression efficiently.
Abnormal Localization and Accumulation of FLT3-ITD, a Mutant Receptor Tyrosine Kinase Involved in Leukemogenesis
Authors: Koch Sina , Jacobi Angela , Ryser Martin , Ehninger Gerhard , Thiede Christian
Published: February 2008

Aberrant subcellular localization of mutant transmembrane receptors is increasingly acknowledged as a possible mechanism for an altered signaling quality leading to transformation. There is evidence that mutated receptor tyrosine kinases of subclass III, for example the platelet-derived growth factor receptor (PDGFR) and KIT-protein, are aberrantly localized in human cancers. In order to further analyze this phenomenon, we investigated the localization of FLT3, a subclass III receptor tyrosine kinase frequently mutated in leukemia. By immunofluorescence staining and confocal laser scanning microscopy we found that in retrovirally transduced COS7 cells, wild type FLT3 receptor protein is localized primarily at the cell surface. In contrast, a mutant FLT3 receptor protein with an internal tandem duplication (ITD) accumulates in a perinuclear region and is not detectable at the plasma membrane. Surprisingly, and in contrast to previously published data, intracellular FLT3-ITD accumulation could neither be detected in the endoplasmic reticulum (ER) nor in the Golgi apparatus. Furthermore, transient overexpression per se leads to accumulation of wild type FLT3 receptor protein in the ER in addition to surface localization, probably due to inefficient intracellular transport by the overloaded sorting machinery of the secretory pathway. Based on our data and the immature glycosylation pattern of FLT3-ITD, we speculate that the mutant protein resides most probably in an unidentified compartment of the secretory pathway between the ER and the Golgi apparatus.
Role of Horizontal Transmission in Hepatitis B Virus Spread among Household Contacts in North India
Authors: Gupta Swati , Gupta Richa , Joshi Y.K. , Singh Sarman
Published: February 2008

Objectives: Familial clustering of HBV provides epidemiological evidence for the different modes of spread of the virus. Though the majority of the studies have addressed the issue of perinatal transmission in India, only a few reports have dealt with other modes of transmission. Methods: The study was prospectively designed and data were collected from a total of 265 household contacts of 91 index patients with HBV-related chronic liver disease between January 2006 and July 2007. The prevalences of HBsAg and various antibodies; anti-HBs, anti-HBc and anti-HBe, were estimated in all household contacts using ELISA and VIDAS. Results: Among the various household contacts, the highest prevalence of HBsAg was seen in the pediatric age group (kids 1–15 years: 37.0%) and especially in siblings (48.3%), with statistical significance (p < 0.001). Hepatitis B virus (HBV) serological markers were found more commonly in contacts of female (68.8%) index patients as compared to males (p > 0.05). The development of anti-HBV antibodies showed an increasing trend with age (p < 0.001), with the highest prevalence in parents. Conclusion: Horizontal transmission plays an important role in contributing to the high prevalence of HBsAg especially in young children. Hence, this age group needs to be targeted for primary prevention and effective vaccine.
Prediction of Alzheimer’s Disease Using a Cerebrospinal Fluid Pattern of C-Terminally Truncated β-Amyloid Peptides
Authors: Höglund K. , Hansson O. , Buchhave P. , Zetterberg H. , Lewczuk P. , Londos E. , Blennow K. , Minthon L. , Wiltfang J.
Published: February 2008

Background: Identifying individuals at high risk of developing Alzheimer’s disease (AD) is important for future therapeutic strategies, and there is a clinical need for diagnostic biomarkers to identify incipient AD. Objective: The aim of the present study was to investigate if the AD-associated Aβ peptide pattern recently found in cerebrospinal fluid (CSF) could discriminate between patients with incipient AD and those with stable mild cognitive impairment (MCI) by analyzing CSF from patients with MCI at baseline. Methods: The levels of Aβ1-37, -38, -39, -40, -42 were analyzed by Aβ-SDS-PAGE/immunoblot in CSF from 19 healthy controls, 25 patients with stable MCI and from 25 patients with MCI who later developed AD during 4- to 6-year follow-up. Results: All healthy controls and 20 out of 22 patients who developed AD were correctly classified by their baseline Aβ peptide pattern. In 9 out of 25 stable MCI patients, the pattern indicated incipient AD in spite of clinical nonconversion. Interestingly, these individuals had apolipoprotein E genotypes and CSF levels of tau and phospho-tau that are known to be associated with high risk of AD. Conclusion: Altogether, our study reveals the novel finding that the Aβ peptide pattern is able to predict AD in patients with MCI with a sensitivity of 91% and specificity of 64%. The specificity would increase to 94% if the high-risk patients in the stable MCI cohort developed AD during extended follow-up.