bluuebunny/crossref_metadata_2025 huggingface dataset:
Interaction of CD44 variant isoforms with hyaluronic acid and the cytoskeleton in human prostate cancer cells
Authors: Welsh Catherine F. , Zhu Dan , Bourguignon Lilly Y. W.
Published: February 2005

CD44 is a glycosylated adhesion molecule which may undergo alternative splicing of 10 possible exons to generate variant isoforms. A number of CD44 variant isoforms expressed by tumor cells have been correlated with metastatic and proliferative behavior. In this study, we have characterized CD44 isoform expression on three prostate cancer cell lines: ALVA‐31, PPC‐1, and LNCaP. Using reverse transcriptase‐polymerase chain reaction, we have found that ALVA‐31 and PPC‐1 cells express multiple CD44 isoforms, including CD44s (standard form), CD44E (epithelial form), and an exon 14‐containing form. In addition, two smaller forms have been detected: one using an alternative donor splice site within exon 5, and a novel form omitting exon 5 entirely. The CD44 isoforms expressed by ALVA‐31 and PPC‐1 cells appear to be preferentially located on the cell surface. By contrast, LNCaP cells do not express any of the CD44 forms at the RNA or protein level. Both PPC‐1 and ALVA‐31 cells display tumorigenesis and invasiveness in nude mice, whereas LNCap cells exhibit a less malignant phenotype, suggesting a correlation between CD44 variant (CD44v) expression and aggressive prostate tumor behavior. Functional characterization reveals that CD44 mediates prostate cell adhesion to extracellular hyaluyronic acid (HA). In addition, the CD44 cytoplasmic domain binds specifically to ankyrin, a membrane cytoskeletal protein. Double immunofluorescence labeling and confocal microscopic analyses indicate that HA binding induces the HA receptor (i.e., CD44) to form capped structures. Importantly, intracellular ankyrin is preferentially accumulated underneath HA receptor‐capped structures. These results suggest that cytoskeletal proteins such as ankyrin are closely associated with CD44‐mediated signaling events induced by HA. Finally, HA‐mediated transmembrane interactions between CD44 isoforms and cytoskeletal proteins (i.e. ankyrin) may play a pivotal role in regulating tumor cell behavior during human prostate cancer development. © 1995 Wiley‐Liss, Inc.
Regulation of parathyroid hormone/parathyroid hormone‐related protein receptor expression by osteoblast‐deposited extracellular matrix in a human osteoblast‐like cell line
Authors: Hausmann S. , Law F. M. K. , Bonjour J.‐Ph. , Feyen J. , Rizzoli R.
Published: February 2005

Parathyroid hormone (PTH) receptors and the biological response to PTH in osteoblasts have been shown to be influenced by glucocorticoids, growth factors, cytokines or PTH itself. Furthermore, components of extracellular matrix (ECM) appear to regulate the response to PTH as well. We investigated the effects of osteoblast‐deposited ECM on PTH‐related protein (PTHrP)‐stimulated cAMP production, PTHrP binding and PTH/PTHrP receptor mRNA in the human osteoblast‐like cell line SaOS‐2. ECM was laid down by the human osteoblastic cell line MG‐63. At confluence, maximal cAMP stimulation induced by 100 nmol/l PTHrP (1–34) was decreased in SaOS‐2 cells grown on ECM as compared with cultures on plastic dishes, without any change in PTHrP concentration producing half‐maximal stimulation. In contrast, cAMP production stimulated by PGE2 was increased in cells on ECM. Saturable 125I‐PTHrP binding (as evaluated by Scatchard plot analysis) was markedly diminished in cells grown on ECM (5,600 ± 2,010 vs. 20,700 ± 1,710 binding sites/cell, × ± S.E.M., P < 0.01, n = 4 experiments), without any significant change in affinity (1.3 ± 0.4 vs. 2.5 ± 0.5 nmol/l (NS), in cells on ECM and plastic, respectively). This apparent decrease in membrane receptor density was associated with markedly lower steady state PTH/PTHrP receptor mRNA levels as assessed by Northern blot analysis (ECM/control: 0.4 ± 0.1). A difference in PTH/PTHrP receptor mRNA levels between cells on ECM or on plastic dishes was detectable by 8 hours, but not by 4 hours, after seeding the cells at high density. By 24 hours after plating, PTH/PTHrP receptor mRNA levels were maximally decreased in cells on ECM. These results in the human osteoblast‐like cell line SaOS‐2 indicate that PTH/PTHrP receptors are down‐regulated by growth on ECM. Thus, attachment of bone cells to bone surface could influence differentiation and function of osteoblasts. © 1995 Wiley‐Liss Inc.
Regulation of DNA methyltransferase during differentiation of F9 mouse embryonal carcinoma cells
Authors: Teubner Barbara , Schulz Wolfgang A.
Published: February 2005

DNA becomes demethylated when F9 mouse embryonal carcinoma cells differentiate into parietal endoderm. DNA methyltransferase (DNA‐MTase) activity decreased by 50% during 1 week of differentiation. The level of DNA‐MTase mRNA was also diminished accordingly, but the transcription rate of the DNA‐MTase gene measured by run‐on transcription was essentially unchanged, indicating regulation of DNA‐MTase expression at a posttranscriptional step. The decline of DNA‐MTase mRNA paralleled that of histone H3 mRNA in accord with the notion that DNA‐MTase is preferentially expressed in the S phase of the cell cycle. Since DNA‐MTase expression decreases in parallel with DNA synthesis, DNA demethylation during differentiation of F9 cells appears not to be due to limited expression of DNA‐MTase. However, the plasmid pAFP7000CAT, α‐fetoprotein (AFP), which is strongly de novo methylated when transfected into F9 stem cells became only weakly methylated after transfection into the F9 parietal endoderm derivative P1, indicating that the activity of DNA‐MTase within parietal endoderm cells is more strongly diminished than is apparent from measurements of mRNA amounts and of overall DNA‐MTase activity in vitro. The discrepancy between DNA‐MTase expression and its actual activity within the cell indicates the existence of a novel mechanism controlling the activity of DNA‐MTase. © 1995 Wiley‐Liss, Inc.
Cell cycle variation of Hsp70 levels in HeLa cells at 37°C and after a heat shock
Authors: Hang Haiying , He Liusheng , Fox Michael H.
Published: February 2005

The expression of the 72 kD inducible heat shock protein (hsp72) has been reported to be cell cycle associated in unheated, synchronized HeLa cells. In this study, flow cytomerty was used to investigate hsp72 levels through the cell cycle in HeLa cells by dual labeling with propidium iodide and antibodies against hsp72. The entire cell cycle distribution of hsp72 could be measured in a single sample of asynchronously growing cells. For unheated cells, the level of hsp72 increased about 30% from G1 to S phase, with about a 65% increase in G2/M, probably due to cell size differences. Neither mitotic selection nor serum stimulation induced a higher level of hsp72 than in the control cells. Western blot analysis of hsp72 from Hoechst‐stained cells sorted from G1, mid‐S, or G2/M showed that G1 cells had the lowest level of hsp72, with about a 30% increase in S phase and a 60% increase in G2/M, in good agreement with the flow cytometry results. These data conflict with previous reporty by other laboratories which showed a 3‐fold higher level of hsp72 in S phase than in G1 or G2. In contrast, heat shock (both acute and chronic) led to a non‐uniform increase in hsp72 through the cell cycle. Most cells in mid S phase had high levels of hsp72, and a larger range in the levels of hsp72 were found in G1 and late S/G2/M phase cells. © 1995 Wiley‐Liss, Inc.
Thrombin activates mitogen‐activated protein kinase in primary astrocyte cultures
Authors: Bhat Narayan R. , Zhang Peisheng , Hogan Edward L.
Published: February 2005

Thrombin is known to evoke numerous inflammatory and proliferative responses in a wide variety of its target cells. Recent studies have demonstrated morphoregulatory and mitogenic effects of thrombin on astroglial cells (astrocytes). The present study deals with thrombin‐induced activation of mitogen‐activated protein (MAP) kinase in primary cultures of rat astrocytes. Treatment of serum‐starved astrocytes with thrombin resulted in a rapid activation of tyrosine (Tyr) phosphorylation of a set of proteins including a prominent one with a molecular mass of 42 kDa (p42). The identity of p42 with MAP kinase was confirmed by MAP kinase‐immunoreactivity of isolated [i.e., immunoprecipitated with anti‐phosphotyrosine (PY) antibodies] p42 and by increased myelin basic protein (MBP) kinase activity present in MAP kinase immunoprecipitates of thrombin‐treated cultures. Pertussis toxin (PTX) pretreatment failed to inhibit thrombin stimulation of p42 phosphorylation, indicating the lack of involvement of PTX sensitive G proteins in the mechanism of activation of MAP kinase by thrombin. Chronic exposure of cultures to phorbol 12‐myristate 13‐acetate to down‐regulate PKC resulted in an attenuation of thrombin‐induced p42 Tyr phosphorylation, although H‐7, a known PKC inhibitor, failed to block thrombin effect. However, staurosporine, a nonspecific protein kinase inhibitor, prevented the activation of p42 phosphorylation. It is concluded that thrombin induces MAP kinase activation in astrocytes by a mechanism involving a staurosporine‐sensitive pathway. © 1995 Wiley‐Liss, Inc.
Chemoattractant‐induced activation of vaculoar H+ pumps and of an H+‐selective conductance in neutrophils
Authors: Nanda Arvind , Grinstein Sergio
Published: February 2005

Upon binding to their receptors on the surface of neutrophils, chemotactic peptides elicit a burst of metabolic activity. The excess acid generated by this burst must be rapidly extruded in order to maintain intracellular pH and preserve normal microbicidal responses. Recently, H+‐pumping vacuolar‐type ATPases (V‐pumps) and a H+‐selective conductance were described in the membrane of neutrophils. However, these systems are virtually quiescent in resting cells. In this report, we analyzed whether the V‐pumps and the conductance become active and contribute to pH regulation following cell activation by chemoattractants. Formyl‐Met‐Leu‐Phe (fMLP) was found to stimulate V‐pumps, as assessed by the appearance of bafilomycin‐sensitive H+ extrusion. Concomitantly, the chemoattractant also activated the H+ conductance, detected as a voltage‐dependent and Zn2+‐sensitive net H+ efflux. In both cases, activation was prevented by treatment with competing antagonistic peptides or with pertussis toxin, implying mediation by a receptor copuled to a heterotrimeric G protein. The signalling pathways downstream of the G proteins were also investigated. Stimulation of neither th V‐pump nor the conductace required activation of protein kinase C. An elevation of cytosolic calcium ([Ca2+]i) comparable to that induced by fMLP did not suffice to trigger either transporter. Moreover activation of the conductance remained unaffected when the chemoattractant‐induced increase in [Ca2+]i was precluded. In contrast, stimulation of the V‐pump was substantially (∞50%) depressed when [Ca2+]i was prevented from rising. Tyrosine phosphorylation of several polypeptides accompanies stimulation by fMLP. Prevention of phosphotyrosine accumulation resulted in a pronounced inhibition of H+‐pumping and of the H+ conductance. Together, these data indicate that engagement of surface receptors by chemotactic peptides can lead to stimulation of two voltage‐sensitive pH regulatory pathways, a pump and a conductance, by a pathway that requires tyrosine phosphorylation. Both pathways are capable of sizable H+ extrusion, thereby contributing to pH regulation during the metabolic burst. © 1995 Wiley‐Liss Inc.
Regulation of apoptosis of interleukin 2‐dependent mouse T‐cell line protein tyrosine phosphorylation and polyamines
Authors: Min An , Hasuma Tadayoshi , Yano Yoshihisa , Matsui‐Yuasa Isao , Otani Shuzo
Published: February 2005

We examined the effect of inhibitors of tyrosine kinase and tyrosine phosphatase on DNA fragmentation, protein tyrosine phosphorylation, and polyamine metabolism in the murine T‐cell line CTLL‐2. When cells were exposed to herbimycin A, a specific inhibitor of tyrosine kinase (Uehara et al., 1989, Biochem. Biophs. Res. Commun., 163:803–809), in the presence of interleukin 2 (IL‐2), DNA was degraded into oligonucleosomal fragments in a dose‐dependent fashion. Genistein, another inhibitor of tyrosine kinase (Akiyama et al., 1987, J. Biol. Chem., 262:5592–5596), had similar effects. Exposure of CTLL‐2 cells to vanadate, a tyrosine phosphatase inhibitor, blocked with the DNA fragmentation induced by herbimycin A. Tyrosine phosphorylation of 55 Kd protein was inhibited by herbimycin A, and the inhibition was reduced by vanadate. Ornithine decarboxylase (ODC) activity decreased rapidly after herbimycin A was added to CTLL‐2 cell cultures, while vanadate increased ODC activity. The exogenous addition of putrescine or spermine, but not that of spermidine, attenuated herbimycin A‐induced DNA fragmentation. These findings suggest that phosphorylation of tyrosine residues of 55 Kd protein prevents DNA fragmentation and that polyamines are involved in regulation of apoptosis. © 1995 Wiley‐Liss Inc.
Stretch activated ion channels in ventricular myocytes
Authors: Craelius William , Chen Victor , El-Sherif Nabil
Published: February 2005

Patch-clamp recordings from ventricular myocytes of neonatal rats identified ionic channels that open in response to membrane stretch caused by negative pressures (1 to 6 cm Hg) in the electrode. The stretch response, consisting of markedly increased channel opening frequency, was maintained, with some variability, during long (>40 seconds) stretch applications. The channels have a conductance averaging 120 pS in isotonic KCl, have a mean reversal potential 31 mV depolarized from resting membrane potential, and do not require external Ca++ for activation. The channels appear to be relatively non-selective for cations. Since they are gated by physiological levels of tension, stretch-activated channels may represent, a cellular control system wherein beat-to-beat tension and/or osmotic balance modulate a portion of membrane conductance.
Identification of a dispersed MboI repeat family in five higher plant genomes
Authors: Ranade S. A. , Lagu M. D. , Patankar S. M. , Dabak M. M. , Dhar M. S. , Gupta V. S. , Ranjekar P. K.
Published: February 2005

Digestion of nuclear DNAs of five plants, namely Cucurbita maxima (red gourd), Trichosanthes anguina (snake gourd), Cucumis sativus (cucumber), Cajanus cajan (pigeon pea) and Phaseolus vulgaris (french bean) with the restriction endonuclease MboI yielded discrete size classes with molecular weights in the range of 0.5 to 5 kbp. The MboI digestion pattern of Cot 0.1 DNA in french bean is comparable with that of total DNA, indicating that these bands represented highly repeated DNA sequences. Cleavage of the DNAs with varying amounts of MboI indicated the dispersed nature of the repeat families. Southern hybridization studies using french bean highly repetitive DNA as a probe indicated more homology with repeats of pigeon pea and less homology with red gourd, snake gourd and cucumber repeats.
The effect of clenbuterol on body composition in spontaneously eating tumour-bearing mice
Authors: Hyltander Anders , Svaninger Gösta , Lundholm Kent
Published: February 2005

The aim of this study was to investigate the effect of a selective β2-adrenoceptor agonist, clenbuterol, on body composition in tumour-bearing adult and growing mice. Therefore, adult female C57/BL6 mice (n = 20) were inoculated subcutaneously with a 3-methylcholanthrene-induced sarcoma and divided into two identical groups. One group received injections twice a day of clenbuterol corresponding to 1 mg/kg body weight, the other group received sham injections. Growing mice (n = 20) were similarly divided after tumour inoculation into one study group with clenbuterol injections and one control group. The growing animals were sacrificed on day 11 after commencement of treatment, the adult mice on day 16.

Clenbuterol treatment had no statistically significant effect on accumulated food intake or body composition in the adult mice. However, fooe intake in these animals increased numerically compared to control animals after day 12 of the study. Tumour growth was also unaffected. The growing animals displayed an increased carcass dry weight with borderline significance (p = 0.06) and an increased quadriceps muscle fat free dry weight after clenbuterol treatment. Tumour growth was not affected. Food intake measured on a daily basis was significantly increased in the growing clenbuterol treated animals and accumulated food intake was increased with a trend towards statistical significance (p = 0.06). The results support the suggestion that treatment with a selective β2-adrenoceptor agonist does not improve body composition in tumour-bearing adult mice relying on spontaneous food intake while growing animals may benefit from such treatment.
Copper-zinc superoxide dismutase from Ascaris suum (Nematoda): Purification and characterization
Authors: Sanchez-Moreno Manuel , Entrala Emilio , Janssen Dirk , Osuna Antonio
Published: February 2005

Copper-zinc superoxide dismutase from Ascaris suum (Nematoda) was purified in a new, more efficient, and faster manner. The process included differential centrifugation, fractionation with ammonium sulfate, and sodium dodecyl sulfate-polyacrylamide electrophoresis, yielding a 340-fold purification (specific activity of 47 units/mg). Optimal storage conditions, optimal pH range, thermostability, molecular weight and ultravioltet-visible absorption spectrum of the enzyme are described, and a new enzymatic model for pharmacological screening is suggested.
VLF/ELF sferic evidence for in‐cloud discharge activity producing sprites
Authors: Ohkubo A. , Fukunishi H. , Takahashi Y. , Adachi T.
Published: February 2005

Sprite luminosities produced by winter lightning in Japan were found to be associated with simultaneous occurrences of clusters of radio atmospherics as observed in the VLF range, suggesting an in‐cloud discharge activity. Concurrent ELF data show transient perturbations, indicating continuous charge transfer in causative lightning. These data provide the first evidence that an in‐cloud discharge activity plays an important role in the generation mechanism of sprites.
Statistical thermodynamics for chain molecules with simple RNA tertiary contacts
Authors: Kopeikin Zoia , Chen Shi-Jie
Published: February 2005

A statistical thermodynamic model is developed for chain molecules with simple RNA tertiary contacts. The model, which accounts for the excluded volume effect and the nonadditivity in the free energy, enables reliable predictions for the conformational entropy and partition function for simple tertiary folds. Illustrative applications are made to conformational transitions involving simple tertiary contacts. The model can predict the interplay between the secondary and the tertiary interactions in the conformational changes. Though the present form of the theory is tested and validated in a two-dimensional lattice model, the methodology, which is developed based on a general graphical representation for chain conformations, is applicable to any off-lattice chain representations. Moreover, the analytical formulation of the method makes possible the systematic development of the theory for more complex tertiary structures.
Technique for thermal conductivity measurements for organic materials over a wide temperature range
Authors: Torizuka Kiyoshi , Tajima Hiroyuki
Published: February 2005

We have developed a technique to measure the thermal conductivity, which enables us to measure for organic samples over a wide temperature range between 4K and room temperature. In our technique, two heaters and three thermometers are installed unlike the conventional one-heater-two-thermometer configuration. We describe the detailed design of our cell and the procedure for measurements. We have succeeded in measuring the thermal transport of organic molecular crystals with the conductivity of the order of ∼1W∕Km, by employing our method.
Stand-alone device for the electrolytic fabrication of scanning near-field optical microscopy aperture probes
Authors: Haumann C. , Pelargus Ch. , Frey H. G. , Ros R. , Anselmetti D. , Toquant J. , Pohl D. W.
Published: February 2005

Near-field optical applications require the fast, stable, and reproducible fabrication of scanning near-field optical microscopy (SNOM) aperture probes in the submicrometer range. We have developed a stand-alone device for the electrolytic etching of nanoapertures with an integrated current and optical transmission monitoring and control. Probes with an aperture ranging from 50to100nm were reproducibly fabricated with great reliability. With these probes, high resolution SNOM images of 100nm test patterns and single dye molecules (Rhodamine 6G in poly(vinyl alcohol)) are measured and presented. Not requiring a SNOM setup, the stand-alone device is not only inexpensive and compact, but also insensitive to external disturbances.
Precise orientation of single crystals by a simple x-ray diffraction rocking curve method
Authors: Doucette L. D. , da Cunha M. Pereira , Lad R. J.
Published: February 2005

A simple method has been developed for accurately measuring the crystallographic orientation of a single crystal boule, employing a conventional four-circle x-ray diffraction arrangement in the rocking curve mode which relaxes the need for precise instrument and/or reference alignment. By acquiring a total of eight rocking curve measurements at specific orientations about the specimen azimuth, the absolute miscut angle between a crystal surface and the desired crystallographic plane can be resolved to within ±0.01°.
Auxin-Dependent Cell Division and Cell Elongation. 1-Naphthaleneacetic Acid and 2,4-Dichlorophenoxyacetic Acid Activate Different Pathways
Authors: Campanoni Prisca , Nick Peter
Published: February 2005

During exponential phase, the tobacco (Nicotiana tabacum) cell line cv Virginia Bright Italia-0 divides axially to produce linear cell files of distinct polarity. This axial division is controlled by exogenous auxin. We used exponential tobacco cv Virginia Bright Italia-0 cells to dissect early auxin signaling, with cell division and cell elongation as physiological markers. Experiments with 1-naphthaleneacetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-D) demonstrated that these 2 auxin species affect cell division and cell elongation differentially; NAA stimulates cell elongation at concentrations that are much lower than those required to stimulate cell division. In contrast, 2,4-D promotes cell division but not cell elongation. Pertussis toxin, a blocker of heterotrimeric G-proteins, inhibits the stimulation of cell division by 2,4-D but does not affect cell elongation. Aluminum tetrafluoride, an activator of the G-proteins, can induce cell division at NAA concentrations that are not permissive for division and even in the absence of any exogenous auxin. The data are discussed in a model where the two different auxins activate two different pathways for the control of cell division and cell elongation.
Global Transcription Profiling Reveals Comprehensive Insights into Hypoxic Response in Arabidopsis
Authors: Liu Fenglong , VanToai Tara , Moy Linda P. , Bock Geoffrey , Linford Lara D. , Quackenbush John
Published: February 2005

Plants have evolved adaptation mechanisms to sense oxygen deficiency in their environments and make coordinated physiological and structural adjustments to enhance their hypoxic tolerance. To gain insight into how plants respond to low-oxygen stress, gene expression profiling using whole-genome DNA amplicon microarrays was carried out at seven time points over 24 h, in wild-type and transgenic PSAG12:ipt Arabidopsis (Arabidopsis thaliana) plants under normoxic and hypoxic conditions. Transcript levels of genes involved in glycolysis and fermentation pathways, ethylene synthesis and perception, calcium signaling, nitrogen utilization, trehalose metabolism, and alkaloid synthesis were significantly altered in response to oxygen limitation. Analysis based on gene ontology assignments suggested a significant down-regulation of genes whose functions are associated with cell walls, nucleosome structures, water channels, and ion transporters and a significant up-regulation of genes involved in transcriptional regulation, protein kinase activity, and auxin responses under conditions of oxygen shortage. Promoter analysis on a cluster of up-regulated genes revealed a significant overrepresentation of the AtMYB2-binding motif (GT motif), a sugar response element-like motif, and a G-box-related sequence, and also identified several putative anaerobic response elements. Finally, quantitative real-time polymerase chain reactions using 29 selected genes independently verified the microarray results. This study represents one of the most comprehensive analyses conducted to date investigating hypoxia-responsive transcriptional networks in plants.
The evolutionary species pool hypothesis and patterns of freshwater diatom diversity along a pH gradient
Authors: Pither Jason , Aarssen Lonnie W.
Published: February 2005

Aim  To interpret the unimodal relationship between diatom species richness and lake pH within the context of the evolutionary species pool hypothesis (SPH). We test the following primary prediction arising from the SPH: the size of the potential species pool (PSP) will increase along a gradient representing the historical commonness of different pH environments (pH commonness). To do this we assume that the present‐day spatial dominance of near‐neutral pH conditions compared with acidic and alkaline conditions reliably mimics the relative spatial availabilities of historical pH conditions among freshwater lakes. We also determine whether local richness represents a constant proportion of PSP size along the pH commonness gradient.

Location  Two hundred and thirty‐four lakes distributed over a 405,000 km2 region of the north‐eastern United States of America.

Methods  Sediment diatom morphospecies lists and pH data were acquired from the US Environmental Protection Agency's Environmental Monitoring and Assessment Program (EMAP) website. Using 248 morphospecies that occurred in at least 10 of the 234 lakes, four different measures of PSPs were calculated along the pH gradient. Local species richness was equated with the number of species occurring within the lake. Alpha diversity was equated with the average species richness of lakes with similar pH values. A combination of statistical methods were employed, including correlations, quadratic regression and piecewise regression.

Results  PSP size increased significantly with pH commonness for all four measures of PSP size, thus supporting the primary prediction of the evolutionary SPH. Local richness comprised a larger proportion of the PSP within acidic lakes than within circumneutral lakes. Alpha diversity and lake species richness both increased significantly with pH commonness, but the former did so in a two‐step fashion. We test and reject several alternative contemporary time‐scale explanations for our findings.

Main Conclusions  Our findings are consistent with the hypothesis that diatom taxonomic richness is presently lower within acidic and highly alkaline lakes than in circumneutral lakes owing to the limited opportunity in space and/or time for the evolution of suitably adapted species. Whereas ecological processes can explain why certain species are excluded from particular habitats, e.g. acidic lakes, they cannot account for why so few species are adapted to those habitats in the first place.
Biogeographical patterns in the Western Palearctic: the fasting‐endurance hypothesis and the status of Murphy's rule
Authors: Meiri Shai , Dayan Tamar , Simberloff Daniel
Published: February 2005

Aim  In Europe, winter severity is positively correlated with longitude. We test how this climatic cline affects biogeographical patterns in Western Palearctic homeotherms.

Location  Eurasia, west of 60° longitude.

Methods  We test the effects of longitude on body size of carnivores, using cranial measurements of 2002 specimens belonging to 11 species. We test the effects of longitude on migration patterns of birds by comparing which populations of partial migrants are sedentary and which undergo winter migration.

Results  Carnivore body size does not vary consistently with longitude. Populations of partial migrants are more likely to be sedentary in western Europe and to migrate from eastern Europe than vice versa.

Main conclusions  Longitudinal patterns in climate exert a selective force on birds but do not affect carnivore size in a consistent, predictable manner. We find no support for the mechanism suggested to promote size change, namely the fasting‐endurance hypothesis.
Differentially expressed genes during seed development in soybean
Authors: Beilinson Vadim , Moskalenko Oleksandr V. , Ritchie Rae D. , Nielsen Niels C.
Published: February 2005

Little reliable information exists about the genetic events that control the onset and timing of seed‐fill in soybean cotyledons. To identify the genes involved in this process, cDNA libraries were prepared from mRNAs isolated from seeds at 7 and 21 days after flowering (DAF), which represent times just before and after the initiation of seed‐fill. For the soybean variety Resnik, which was used for this study, seed‐fill and the establishment of an endoreduplicative cell cycle occurred 12–14 DAF. Suppression subtractive hybridization was then applied to identify sequences that were differentially expressed at each of these two developmental stages. False positives in the libraries were reduced by using mirror orientation selection (MOS). The libraries of differentially expressed genes that resulted were analysed and the nucleotide sequences obtained were compared with those in existing databases. Several genes from each library were chosen and their expression profile during seed development was analysed by quantitative reverse transcriptase‐polymerase chain reaction (RT‐PCR) using RNA preparations originating from different seed developmental stages. Candidate genes for control of the stage shift from dividing cells to endoreduplication were identified.
Expression of Pax group III genes suggests a single‐segmental periodicity for opisthosomal segment patterning in the spider Cupiennius salei
Authors: Schoppmeier Michael , Damen Wim G. M.
Published: February 2005

Summary
Pair‐rule patterning forms a key step for segmentation in insects. The expression patterns of pair‐rule gene orthologs in representatives of other arthropod groups imply that these genes were segmentation genes in the last common ancestor of the various arthropod groups, but almost nothing is known about the underlying mechanism in noninsect arthropods. Here, we cloned and analyzed members of the Pax group III genes from the spider Cupiennius salei. Pax group III genes comprise genes like the Drosophila genes paired, gooseberry, and gooseberry‐neuro, as well as the vertebrate Pax 3 and Pax 7 genes. We recovered three Pax group III genes from the spider C. salei, Cs‐pairberry‐1, Cs‐pairberry‐2, and Cs‐pairberry‐3, and show that the combined expression of the three spider genes mimics the patterns in insects, suggesting an ancestral role for Pax group III genes in segmentation, neurogenesis, and appendage formation in arthropods. One of the genes, pairberry‐3, is expressed in a segmental periodicity before overt morphological segmentation is visible, suggesting a single segmental periodicity for opisthosomal segment pattering in the spider. Comparisons among arthropods suggest that the underlying mechanisms for pair‐rule gene orthologs are more diverged than the ones for the segment‐polarity genes. We argue that there may be a correlation between the lower variation in patterns of segment‐polarity genes and the phylotypic stage. The segment‐polarity genes are required to define the segment borders of the embryo at the germ‐band stage, the arthropod phylotypic stage. Pair‐rule gene orthologs act more upstream and may display more variation in their action.
Cost effectiveness of a community based research project to help women quit smoking
Authors: Secker-Walker R H , Holland R R , Lloyd C M , Pelkey D , Flynn B S
Published: February 2005

Objective:To estimate the cost effectiveness of a four year, multifaceted, community based research project shown previously to help women quit smoking.

Design:A quasi-experimental matched control design.

Setting:Two counties in Vermont and two in New Hampshire, USA.

Subjects:Women aged 18–64 years.

Methods:Costs were the grant related expenditures converted to 2002 US$. Survey results at the end of the intervention were used to estimate the numbers of never smokers, former smokers, light smokers, and heavy smokers in the intervention and comparison counties, and 1986 life tables for populations of US women categorised by smoking status to estimate the gain in life expectancy.

Main outcome measures:Cost effectiveness ratios, as dollars per life-year saved, for the intervention only and for total grant costs (intervention, evaluation and indirect costs).

Results:The cost effectiveness ratio for the intervention, in 2002 US$ per life-year saved, discounted at 3%, was $1156 (90% confidence interval (CI) $567 to ∞), and for the total grant, $4022 (90% CI $1973 to ∞). When discounted at 5%, these ratios were $1922 (90% CI $1024 to $15 647), and $6683 (90% CI $3555 to $54 422), respectively.

Conclusion:The cost effectiveness ratios of this research project are economically attractive, and are comparable with other smoking cessation interventions for women. These observations should encourage further research and dissemination of community based interventions to reduce smoking.
A prospective study of off-label use of, abuse of, and dependence on nicotine inhaler
Authors: Hughes J R , Adams E H , Franzon M A , Maguire M K , Guary J
Published: February 2005

Objective:To determine the incidence of off-label use of, abuse of, and dependence on prescription nicotine inhaler.

Design:Prospective telephone and internet interviews for six months.

Participants:535 new inhaler users.

Main outcome:Structured interview about off-label use (that is, use of inhaler for non-cessation reasons or concurrent use of inhaler and cigarettes) andDiagnostic and statistical manual, fourth edition (DSM-IV) andInternational classification of diseases, 10th edition (ICD-10) criteria for abuse and dependence

Results:Although many used inhaler and cigarettes concurrently at some time (43–55%), few used inhaler for non-cessation reasons (4–9%) and few persisted in off label use (8–16%; 95% confidence interval (CI) 5% to 19%). No participant met ICD-10 criteria for harmful use/abuse (95% CI 0% to 3.3%). Eight subjects (1.4%) appeared to meet DSM-IV or ICD-10 criteria for dependence on inhaler, but none were found dependent in a clinical expert interview (95% CI 0% to 3.3%).

Conclusions:Although transient concurrent use of inhaler and cigarettes often occurs, use for non-cessation reasons, abuse and dependence are rare.
Variants of the tissue-sensor array window chamber
Authors: Makale Milan T. , Chen Peter C. , Gough David A.
Published: February 2005

Sensors are being developed that can be implanted in tissues for continuous monitoring of oxygen, glucose, and other metabolites. However, there have been difficulties in inferring metabolite concentrations in blood from the signals of tissue sensors due to the properties of tissues at the implant site and local physiological phenomena that can affect sensor responses. A multisensor array has been previously developed for implantation in a hamster skinfold window chamber preparation to study these effects. The preparation allows recording of concentration-dependent signals from multiple sensors while nondestructively visualizing the adjacent tissue and microvascular function. Variants of the tissue-sensor array window chamber described here have respective advantages over the original chamber design, including improved tissue visualization and reduced surgical intervention, and allow exposure of the sensor to different tissues. Results indicate that mass transfer within tissues is heterogeneous, and sensor signals are affected by variable perfusion of local microvasculature in addition to vascular metabolite concentration. These observations suggest new strategies for sensor design and operation. Window chamber variants are important tools for validation of implanted sensors.
Darius in Place of Cyrus: The First Edition of Deutero-Isaiah (Isaiah 40.1-52.12) in 521 bce
Authors: Albertz Rainer
Published: February 2005

It can be called a scholarly consensus that the salvific king announced in Deutero-Isaiah is to be identified with the Persian emperor Cyrus. According to this opinion most of the book emerged before Cyrus’ victory over the Neo-Babylonian empire in 539 bce. But a closer reading reveals that only one of the royal oracles names Cyrus explicitly (Isa. 44.24-45.7), whereas three remain anonymous (45.5-7; 45.11-13*; 48.12-15). Recent studies on the redactional history of the book agreed that its first edition was written around 520 bce. The present article points out that such an edition can be understood much better if we apply the anonymous oracles to Darius, who usurped the Persian throne in 522 and captured the revolting city of Babylon in winter 522 and summer 521 bce.
‘Knock, Knock, Knockin’ on Sodom’s Door’: The Function of [ILLEGIBLE]/[ILLEGIBLE] in Genesis 18-19
Authors: Doyle Brian
Published: February 2005

The history of research into chs. 18-19 of the book of Genesis has tended to be a history of entrenchment and the provision of support for a ground-text which can be employed for the biblical condemnation of same-gender, genitally expressed sexuality. A close reading of the narrative reveals, however, that the story has been peppered with a number of clues consciously designed to lead the reader to a more or less comprehensive interpretation of an otherwise ambiguous text. This article contends that the ‘sexual’ reading of the Mamre-Sodom narrative is thus by no means the most comprehensive and that its author’s use, among other things, of the key words [ILLEGIBLE] and [ILLEGIBLE] further support an alternative reading in which sex and sexuality have no significant role to play.
Genome wide analysis of Arabidopsis core promoters
Authors: Molina Carlos , Grotewold Erich
Published: February 2005

Background

Core promoters are the gene regulatory regions most proximal to the transcription start site (TSS), central to the formation of pre-initiation complexes and for combinatorial gene regulation. The DNA elements required for core promoter function in plants are poorly understood. To establish the sequence motifs that characterize plant core promoters and to compare them to the corresponding sequences in animals, we took advantage of available full-length cDNAs (FL-cDNAs) and predicted upstream regulatory sequences to carry out the analysis of 12,749 Arabidopsis core promoters.

Results

Using a combination of expectation maximization and Gibbs sampling methods, we identified several motifs overrepresented in Arabidopsis core promoters. One of them corresponded to the TATA element, for which an in-depth analysis resulted in the generation of robust TATA Nucleotide Frequency Matrices (NFMs) capable of predicting Arabidopsis TATA elements with a high degree of confidence. We established that approximately 29% of all Arabidopsis promoters contain TATA motifs, clustered around position -32 with respect to the TSS. The presence of TATA elements was associated with genes represented more frequently in EST collections and with shorter 5' UTRs. No cis-elements were found over-represented in TATA-less, compared to TATA-containing promoters.

Conclusion

Our studies provide a first genome-wide illustration of the composition and structure of core Arabidopsis promoters. The percentage of TATA-containing promoters is much lower than commonly recognized, yet comparable to the number of Drosophila promoters containing a TATA element. Although several other DNA elements were identified as over-represented in Arabidopsis promoters, they are present in only a small fraction of the genes and they represent elements not previously described in animals, suggesting a distinct architecture of the core promoters of plant and animal genes.
Canavanine-induced longevity in mice may require diets with greater than 15.7% protein
Authors: Brown Dan L
Published: February 2005

Background

Dietary administration of 1% canavanine had been shown to improve survival in female BALB/c mice consuming diets containing 23.4% protein (dry matter basis).

Methods

In order to determine if this effect also obtains at more moderate dietary protein concentrations, 30 female BALB/c mice were fed a basal diet with 14% protein (15.7% dry matter basis) and another 30 were fed the same diet plus 1% canavanine.

Results

Neither mean (Control 873.2 d, Canavanine 870.0 d; SEM = 34.2 d; P = 0.949 from ANOVA) nor median (Control 902 d, Canavanine 884.5 d; P = 0.9058 from Mann-Whitney) lifespans differed between groups.

Although mean antinuclear antibody (ANA) titers did not differ between control and canavanine-treated mice at 833 days of age (19.84 vs 20.39 respectively; SEM = 2.64; P = 0.889 from ANOVA), one canavanine-treated mouse displayed an outlying ANA value of 50 (next lower value = 30) denoting possible early sign of incipient autoimmune disease in that individual.

Conclusion

There may be an interaction between dietary protein level and canavanine with respect to lifespan in mice.
Innervation of the pulmonary artery bifurcation of the cat
Authors: Verity M. Anthony , Hughes Trevor , Bevan John A.
Published: February 2005

The gross and microscopic innervation of the bifurcation and extrapulmonary portion of the pulmonary artery in the adult cat is described. Morphopharmacologic studies indicated that the major efferent and afferent innervation is contributed by the right recurrent cardiac nerve, a branch of the recurrent laryngeal.

A morphologic description of the adventitial nerve bundles, preterminal axon plexus and medial, fine unmyelinated neurites as seen in methylene blue and Bielschowsky silver preparations is given. Rare, classical, pressoreceptor arborizations of de Castro type II were identified, but evidence was presented of degenerative and regenerative neural activity in the adventitial and pre‐terminal plexus manifested by irregular axonic swellings, myelin ellipsoids with vacuolation, terminal growth cones and collateral sprouting. In these degenerative zones, the plexus assumed a more discontinuous organization showing features very suggestive of a simple pressoreceptor system composed predominantly of de Castro type I terminations.

The in vitro pharmacologic studies using the isolated pulmonary artery‐nerve preparation confirmed the existence of effector, vasoconstrictor adrenergic sympathetic fibers in the recurrent cardiac nerve. Small unmyelinated perivasal and perivasal collateral fibers disappear or show severe degenerative changes following bilateral sympathectomy, and are considered to represent the sympathtic autonomic component.
Ultrastructure of developing muscle cells in the chick embryo
Authors: Allen E. Raworth , Pepe Frank A.
Published: February 2005

Sectioned as well as negatively stained preparations of developing myotomal cells from the chick embryo were studied with the electron microscope. The application of these two techniques to similar material made it possible to observe developing muscle cells in successive stages of differentiation and at the same time visualize some of the isolated components making up these cells.

The thick and thin filaments observed in the embryonic muscle were morphologically indistinguishable from those observed in adult muscle. The thin filaments, found randomly dispersed in the cytoplasm of the early cells, were present in large concentrations before the first appearance of thick filaments. The first observed thick filaments had lengths of 1.5 μ, equal to that of adult thick filaments. The appearance of large polyribosomes was correlated with the first appearance of the thick filaments. Single and small groups of ribosomes were always present. Early formed thick and thin filament aggregates were found in the same hexagonal array that is typical to the organization of myofilaments in adult myofibrils. Non‐striated myofibrils, associated with a periodic transverse tubular system, were found before striated myofibrils could be observed. Some preliminary observations were made concerning the appearance of glycogen particles.
Spinal cord segments. B. Gross structure in the adult monkey
Authors: Thomas Carolyn Eyster , Combs C. Murphy
Published: February 2005

Dorsal and ventral roots were dissected bilaterally on spinal cords of adult monkeys: six rhesus, six irus and three baboons. Measurements made were: the distance between the uppermost cord attachments of successive nerve roots (segment length); the distance between the uppermost and lowermost fila within each root (root attachment length); and the distance beween the lowermost fila of one root and the uppermost fila of the subjacent root (interroot length). Segment lengths, dorsally and ventrally, are essentially alike within each species. In rhesus the average at various levels ranges from 4½ mm in cervical and sacral to 12½ mm in lower thoracic; in irus, from 4 mm in cervical and sacral to 10 mm in lower thoracic; in the baboon, from 5½ mm in cervical and sacral to 19 mm in lower thoracic. Within each species the dorsal and ventral root attachment lengths are similar, as are the interroot lengths, except in the lower thoracic levels. There dorsal interroot lengths range up to 3 mm longer than ventral. Cross sectional areas of the various levels were planimetrically determined. Within each species the largest areas are at lower cervical and lower lumbar levels. Individual segment volumes were calculated. In rhesus and irus these vary only about 60 mm3 from the largest to the smallest segment, excluding sacrocaudal levels. In baboon this difference is as much as 260 mm3.
Further evidence for the presence of nigro‐neostriatal dopamine neurons in the rat
Authors: Andén Nils‐Eric , Dahlström Annica , Fuxe Kjell , Larsson Knut
Published: February 2005

With the help of the highly specific and sensitive histochemical fluorescence method of Falck and Hillarp for the cellular demonstration of monoamines the catecholamine‐containing cell‐bodies within the brain stem have been studied after unilateral removal of a large part of the neostriatum 1 to 28 days after the operation.

Most of the catecholamine‐containing cell‐bodies within the substantia nigra — but no other monoamine‐containing cell‐bodies — appeared to be distinctly increased in fluorescence intensity and somewhat swollen 2 to 4 days after operation while after 3 to 4 weeks they showed a marked to very marked decrease in fluorescence intensity together with marked degenerative changes. Parallel with the changes in the cell‐bodies there occurred a rapid and marked accumulation of catecholamines within very abundant swollen nerve fibers in the internal capsule. These nerve fibers were traced caudally via the retrolenticular part of the internal capsule down to the crus cerebri. These results together with those in a previous paper (Andén, Carlsson, Dahlström, Fuxe, Hillarp and Larsson, 1964) seem to provide conclusive evidence for the presence of nigro‐neostriatal dopamine neurons.