bluuebunny/crossref_metadata_2025 huggingface dataset:
Hyperperfusion Syndrome After Stenting for Intracranial Vertebral Stenosis
Authors: Rezende Marco Túlio , Spelle Laurent , Mounayer Charbel , Piotin Michel , Abud Daniel Giansante , Moret Jacques
Published: December 2005

Background and Purpose—

Hyperperfusion syndrome is a rare but well-described complication after endarterectomy or stenting in the carotid circulation.

Summary of Case—

A 66-year-old man who had vertebrobasilar insufficiency refractory to medical treatment because of an intracranial right side vertebral stenosis was referred to our institution for endovascular treatment. Stenting was performed, and after 24 hours, he became extremely agitated, and this was followed by a period of apathy without focal neurological deficits. MRI showed bilateral thalamic hemorrhage.

Conclusion—

To our knowledge, this is the first report of hyperperfusion syndrome with hemorrhagic presentation after intracranial vertebral artery stenting.
Carotid Intima-Media Thickening Indicates a Higher Vascular Risk Across a Wide Age Range
Authors: Lorenz Matthias W. , von Kegler Stefan , Steinmetz Helmuth , Markus Hugh S. , Sitzer Matthias
Published: December 2005

Background and Purpose—

Carotid intima-media thickness (IMT) is an independent predictor of vascular events in age groups >45 years. However, there is little information about the predictive value of IMT in younger individuals.

Methods—

In the Carotid Atherosclerosis Progression Study (CAPS; n=5056; age range 19 to 90 years; mean age 50.1 years), common carotid artery (CCA) IMT, bifurcation IMT, internal carotid artery IMT and vascular risk factors were evaluated at baseline. The incidence of stroke, myocardial infarction (MI), and death was determined prospectively. Data for younger (<50 years; n=2436) and older subjects (≥50 years; n=2620) were analyzed separately using Cox proportional hazard regression models.

Results—

During a mean follow-up period of 4.2 years, there were 228 cases of MI, 107 strokes, and 50 deaths. IMT at all carotid segments was highly predictive of all end points (eg, hazard rate ratios [HRRs] per 1 SD CCA-IMT increase were 1.43 [95% CI: 1.35 to 1.51] for MI, 1.47 [1.35 to 1.60] for stroke, and 1.45 [1.38 to 1.52] for MI, stroke or death; all
P
<0.0001). Even after adjustment for age, sex, and vascular risk factors, the predictive value of CCA-IMT and bifurcation IMT remained significant for MI and the combined end point. For the latter, the HRRs were considerably higher in the younger than in the older age group (eg, HRR per 0.1 mm CCA-IMT was 1.34 [1.16 to 1.55] vis-à-vis 1.10 [1.05 to 1.15];
P
=0.011 for age-IMT interaction).

Conclusions—

Carotid IMT independently predicts future vascular events. Its predictive value is at least as high in younger subjects as in older subjects.
Infratentorial Abnormalities in Vascular Dementia
Authors: Bastos Leite António J. , van der Flier Wiesje M. , van Straaten Elisabeth C. W. , Scheltens Philip , Barkhof Frederik
Published: December 2005

Background and Purpose—

Infratentorial abnormalities may cause cognitive deficits, but current research criteria for vascular dementia (VaD) do not consider them. Our purposes were to determine the prevalence of infratentorial abnormalities in VaD, their relation with supratentorial abnormalities, and whether they are relevant to cognition.

Methods—

We examined 182 patients (120 men, mean age=73 years, SD=8) with probable VaD at inclusion into a multicenter clinical trial. MRI scans were evaluated for infratentorial vascular abnormalities, midbrain atrophy, cerebellar atrophy, basilar artery diameter and tortuosity, and supratentorial abnormalities. Cognitive testing included the mini–mental state examination (MMSE) and the vascular dementia assessment scale (VaDAS-cog).

Results—

One hundred forty-one (77.5%) patients had infratentorial abnormalities: 119 (65.4%) had focal infratentorial vascular lesions, 65 (35.7%) had diffuse pontine vascular abnormalities hyperintense on T2-weighted images, 20 (11.0%) had midbrain atrophy, and 16 (8.8%) had cerebellar atrophy. Significant correlations were found between number of infratentorial vascular lesions and basilar artery diameter (

r
s
=0.26;

P
<0.0001), infratentorial and basal ganglia (including thalamus) vascular abnormalities (

r
s
=0.30;

P
<0.0001), as well as between midbrain atrophy and global supratentorial atrophy (

r
s
=0.27;

P
<0.0001). Infratentorial vascular abnormalities and cerebellar atrophy were not significantly associated with cognitive impairment. Patients with midbrain atrophy performed worse on cognitive tests than those without midbrain atrophy. After correction for sex, age, education, supratentorial abnormalities, and center, midbrain atrophy remained significantly associated with lower MMSE scores (
P
<0.05).

Conclusions—

Infratentorial abnormalities often occur in patients with VaD, but only midbrain atrophy was found to be relevant to cognition.
Global Trade and Technology Regimes: The South's Asymmetrical Struggle
Authors: Patterson Rubin
Published: December 2005

The trade and technology regimes of WTO and TRIPS embody the values, objectives, and operational dynamics that primarily satisfy Western powers. Southern states submit to these constraining regimes only to the extent of avoiding severe penalties. They feign compliance whenever possible through "stealthy noncompliance" in order to advance their development and security. This paper addresses three issues: the West-South asymmetrical struggle over technology and trade; the role of state-supported technological development in the South; and the prospective consequences for the South relating to the restricted labor-absorbing capacity of twenty-first century technology.
Globalization and the Requirements of "Good" Environmental Governance
Authors: Bernstein Steven
Published: December 2005

A growing number of regulations and agencies dealing with the global environment directly affect citizens' lives. In these conditions, a conventional division between international and domestic issues, and between normative and explanatory theory, becomes less tenable, raising corresponding issues of legitimacy, community, and ethics. This chapter assesses liberal environmentalism in terms of a normative theory that considers requirements of authority, epistemic validity, good practices, and practical reason. Despite improvements in terms of efficiency and legitimacy, serious concerns remain concerning the foundations of "good" environmental governance.
Humanitarian Intervention and the Question of Sovereignty: The Case of ASEAN
Authors: Narine Shaun
Published: December 2005

The Association of Southeast Asian Nations (ASEAN) has thrived as a regional institution that defends the traditional understanding of Westphalian sovereignty. In the post-Cold War era, however, pressure from within the international community to redefine sovereignty to accommodate humanitarian intervention has placed ASEAN in a difficult position. Historically, ASEAN has actively opposed the idea of humanitarian intervention. However, the ASEAN states have had to acknowledge that such a norm is emerging within the international society. Moreover, ASEAN's inconsistent defense of its professed values, particularly its reaction to the US invasion of Iraq, has undermined ASEAN's ability to defend the traditional definition of sovereignty.
The Adequacy of Repeated-Measures Regression for Multilevel Research
Authors: Misangyi Vilmos F. , LePine Jeffery A. , Algina James , Goeddeke Francis
Published: December 2005

The authors assess the suitability of repeated-measures regression (RMR) to analyze multilevel data in four popular multilevel research designs by comparing results of RMR analyses to results of analyses using techniques known to produce correct results in these designs. The findings indicate that RMR may be suitable for only a small number of situations and that repeated-measures ANOVA, multivariate repeated-measures ANOVA, and multilevel modeling may be better suited to analyze multilevel data under most circumstances. The authors conclude by offering recommendations regarding the appropriateness of the different techniques given the different research designs.
SNP-VISTA: An interactive SNP visualization tool
Authors: Shah Nameeta , Teplitsky Michael V , Minovitsky Simon , Pennacchio Len A , Hugenholtz Philip , Hamann Bernd , Dubchak Inna L
Published: December 2005

Background

Recent advances in sequencing technologies promise to provide a better understanding of the genetics of human disease as well as the evolution of microbial populations. Single Nucleotide Polymorphisms (SNPs) are established genetic markers that aid in the identification of loci affecting quantitative traits and/or disease in a wide variety of eukaryotic species. With today's technological capabilities, it has become possible to re-sequence a large set of appropriate candidate genes in individuals with a given disease in an attempt to identify causative mutations. In addition, SNPs have been used extensively in efforts to study the evolution of microbial populations, and the recent application of random shotgun sequencing to environmental samples enables more extensive SNP analysis of co-occurring and co-evolving microbial populations. The program is available at http://genome.lbl.gov/vista/snpvista[1].

Results

We have developed and present two modifications of an interactive visualization tool, SNP-VISTA, to aid in the analyses of the following types of data: A. Large-scale re-sequence data of disease-related genes for discovery of associated and/or causative alleles (GeneSNP-VISTA). B. Massive amounts of ecogenomics data for studying homologous recombination in microbial populations (EcoSNP-VISTA). The main features and capabilities of SNP-VISTA are: 1) mapping of SNPs to gene structure; 2) classification of SNPs, based on their location in the gene, frequency of occurrence in samples and allele composition; 3) clustering, based on user-defined subsets of SNPs, highlighting haplotypes as well as recombinant sequences; 4) integration of protein evolutionary conservation visualization; and 5) display of automatically calculated recombination points that are user-editable.

Conclusion

The main strength of SNP-VISTA is its graphical interface and use of visual representations, which support interactive exploration and hence better understanding of large-scale SNP data by the user.
An algorithm for automatic evaluation of the spot quality in two-color DNA microarray experiments
Authors: Novikov Eugene , Barillot Emmanuel
Published: December 2005

Background

Although DNA microarray technologies are very powerful for the simultaneous quantitative characterization of thousands of genes, the quality of the obtained experimental data is often far from ideal. The measured microarrays images represent a regular collection of spots, and the intensity of light at each spot is proportional to the DNA copy number or to the expression level of the gene whose DNA clone is spotted. Spot quality control is an essential part of microarray image analysis, which must be carried out at the level of individual spot identification. The problem is difficult to formalize due to the diversity of instrumental and biological factors that can influence the result.

Results

For each spot we estimate the ratio of measured fluorescence intensities revealing differential gene expression or change in DNA copy numbers between the test and control samples. We also define a set of quality characteristics and a model for combining these characteristics into an overall spot quality value. We have developed a training procedure to evaluate the contribution of each individual characteristic in the overall quality. This procedure uses information available from replicated spots, located in the same array or over a set of replicated arrays. It is assumed that unspoiled replicated spots must have very close ratios, whereas poor spots yield greater diversity in the obtained ratio estimates.

Conclusion

The developed procedure provides an automatic tool to quantify spot quality and to identify different types of spot deficiency occurring in DNA microarray technology. Quality values assigned to each spot can be used either to eliminate spots or to weight contribution of each ratio estimate in follow-up analysis procedures.
Microarray analysis of androgen-regulated gene expression in testis: the use of the androgen-binding protein (ABP)-transgenic mouse as a model
Authors: Petrusz Peter , Jeyaraj Durairaj A , Grossman Gail
Published: December 2005

Background

Spermatogenesis is an androgen-dependent process, yet the molecular mechanisms of androgens' actions in testis are poorly understood. Transgenic mice overexpressing rat androgen-binding protein (ABP) in their testes have reduced levels of intratesticular androgens and, as a result, show a progressive impairment of spermatogenesis. We used this model to characterize changes in global gene expression in testis in response to reduced bioavailability of androgens.

Methods

Total RNA was extracted from testes of 30-day old transgenic and wild-type control mice, converted to cRNA, labeled with biotin, and hybridized to oligonucleotide microarrays. Microarray results were confirmed by real-time reverse transcription polymerase chain reaction.

Results

Three-hundred-eighty-one genes (3.05% of all transcripts represented on the chips) were up-regulated and 198 genes (1.59%) were down-regulated by at least a factor of 2 in the androgen-deficient animals compared to controls. Genes encoding membrane proteins, intracellular signaling molecules, enzymes, proteins participating in the immune response, and those involved in cytoskeleton organization were significantly overrepresented in the up-regulated group. Among the down-regulated transcripts, those coding for extracellular proteins were overrepresented most dramatically, followed by those related to proteolysis, cell adhesion, immune response, and growth factor, cytokine, and ion channel activities. Transcripts with the greatest potential impact on cellular activities included several transcription factors, intracellular signal transducers, secreted signaling molecules and enzymes, and various cell surface molecules. Major nodes in the up-regulated network were IL-6, AGT, MYC, and A2M, those in the down-regulated network were IL-2, -4, and -10, MAPK8, SOCS1, and CREB1.

Conclusion

Microarray analysis followed by gene ontology profiling and connectivity analysis identified several functional groups of genes and individual genes responding to sustained reduction of androgen levels in the mouse testis. These include genes whose products function as transcription factors, cell surface molecules including ion channels, extra- and intracellular signaling molecules, and secreted enzymes with the potential of regulating cell-to-cell attachment. The transcription factors CREB1 (down-regulated) and MYC (up-regulated) may mediate the most important initial phases of the testicular response to reduced levels of androgens. These results suggest specific avenues for further research that will lead to a better understanding of how androgens regulate spermatogenesis.
New role for nuclear hormone receptors and coactivators in regulation of BRCA1-mediated DNA repair in breast cancer cell lines
Authors: Crowe David L , Lee Matt K
Published: December 2005

Introduction

The breast cancer susceptibility gene BRCA1 is involved in the repair of double-strand breaks induced by ionizing radiation and chemotherapy drugs. BRCA1 interacts with coactivators such as p300 and CREB-binding protein (CBP) to activate target gene transcription. Estrogen and retinoic acid receptors (ER and RAR) also require coactivator proteins for their ligand-dependent functions. Few studies have suggested a role for nuclear hormone receptors in DNA repair.

Methods

DNA damage and repair activity were quantified with the use of single-cell gel electrophoresis and plasmid end-joining assays. Cell cycle progression and apoptosis were determined by bromodeoxyuridine and TdT-mediated dUTP nick end labelling assays. Stable transfection was accomplished with the lipofection procedure. Protein interaction and expression were determined by immunoprecipitation and western blotting.

Results

17β-Estradiol (E2) and all-trans retinoic acid (RA) had opposing effects on DNA damage and breast cancer cell survival after double-strand break damage. Treatment with E2, but not with RA, resulted in complex formation between ERα, CBP, and BRCA1 in ER-positive cell lines. Mutant BRCA1 reduced the expression and activity of DNA damage repair proteins but did not block nuclear hormone-dependent effects. Mutant BRCA1 failed to form complexes with ERα and CBP, which correlated with its ability to exert E2-independent effects on DNA repair. Mutant BRCA1 inhibited cell cycle progression and produced increased survival in cells with double-strand breaks. Ectopic ERα expression reproduced the E2-mediated effects on DNA damage, repair, and survival.

Conclusion

The present study proposes a new mechanism by which ER and RAR regulate BRCA1-mediated DNA repair by means of CBP.
Steroid Receptor Coactivator-1-Deficient Mice Exhibit Altered Hypothalamic-Pituitary-Adrenal Axis Function
Authors: Winnay Jonathon N. , Xu Jianming , O’Malley Bert W. , Hammer Gary D.
Published: December 2005

Steroidogenic factor-1 (SF-1), has emerged as a critical nuclear receptor regulating development and differentiation at several levels of the hypothalamic-pituitary-steroidogenic axis. Although many coregulatory factors have been shown to physically and functionally interact with SF-1, the relative importance of these interactions in SF-1 target tissues has not been thoroughly established. In this study we assessed roles of steroid receptor coactivator-1 (SRC-1) in hypothalamic-pituitary-adrenal (HPA) axis function using SRC-1-deficient (SRC-1−/−) mice in the absence or presence of SF-1 haploinsufficiency. Surprisingly, SRC-1 deficiency did not alter baseline HPA axis function or the acute rise in corticosterone after ACTH administration and failed to exacerbate adrenocortical dysfunction in SF-1+/− mice. However, after exposure to paradigms of acute and chronic stress, SRC-1−/− mice exhibited an elevation in serum corticosterone despite normal (nonsuppressed) ACTH, suggesting an increase in adrenal sensitivity as well as a concomitant defect in glucocorticoid-mediated feedback inhibition of the HPA axis. An examination of potential compensatory mechanism(s) revealed an increase in adrenal weight, selective elevation of melanocortin 2 receptor mRNA, and a coincident increase in SRC-2 and SRC-3 expression in SRC-1−/− adrenals. A reduction in blood glucose was observed in SRC-1−/− mice after chronic stress, consistent with a generalized state of glucocorticoid resistance. Dexamethasone suppression tests confirmed a weakened ability of glucocorticoids to 1) elevate serum glucose levels and induce hepatic phosphoenolpyruvate carboxykinase transcription and 2) suppress pituitary proopiomelanocortin transcript levels in SRC-1−/− animals. Collectively, these data are consistent with an indispensable role for SRC-1 in mediating actions of glucocorticoids in pituitary and liver.
Androgens Increase Gonadotropin-Releasing Hormone Neuron Firing Activity in Females and Interfere with Progesterone Negative Feedback
Authors: Pielecka Justyna , Quaynor Samuel D. , Moenter Suzanne M.
Published: December 2005

GnRH neurons are the central regulators of fertility, and their activity is modulated by steroid feedback. In women with hyperandrogenemic infertility and in animal models of these disorders, elevated androgen levels interfere with progesterone (P) negative feedback. Our previous work showed that steroids altered the frequency and amplitude of γ-aminobutyric acid (GABA) transmission to GnRH neurons. Specifically, P inhibited GABA transmission, which can excite GnRH neurons, whereas dihydrotestosterone (DHT) increased GABA transmission. In this study the GnRH neuron firing rate was examined in the same animal models. Adult (>2 months) female mice were ovariectomized and treated for 8–12 d with implants containing estradiol (E), E and P, E and DHT, or E, P, and DHT. Targeted extracellular recordings were used to examine the long-term firing activity of green fluorescent protein-identified GnRH neurons in brain slices from these mice. In comparing E alone to E plus P animals, P increased the percentage of time that GnRH neurons were quiescent and reduced the area under the curve of the firing rate and the instantaneous firing frequency, suggesting that P provides additional negative feedback over E alone. The addition of DHT markedly increased GnRH neuron activity in both the presence and absence of P. DHT also altered the firing pattern of GnRH neurons, such that peaks in the firing rate detected by the Cluster8 algorithm were approximately doubled in frequency and amplitude. These data support and extend our previous findings and are consistent with the hypothesis that the changes in GABAergic transmission observed in these animal models impact upon the activity of GnRH neurons, and central androgen action probably stimulates GnRH release.
Estrogen and Tamoxifen Induce Cytoskeletal Remodeling and Migration in Endometrial Cancer Cells
Authors: Acconcia Filippo , Barnes Christopher J. , Kumar Rakesh
Published: December 2005

Much research effort has been directed toward understanding how estrogen [17β-estradiol (E2)] regulates cell proliferation and motility through the rapid, direct activation of cytoplasmic signaling cascades (i.e. nongenomic signaling). Cell migration is critical to cancer cell invasion and metastasis and involves dynamic filamentous actin cytoskeletal remodeling and disassembly of focal adhesion sites. Although estrogen is recognized to induce cell migration in some model systems, very little information is available regarding the underlying pathways and potential influence of selective estrogen receptor modulators such as 4-hydroxytamoxifen on these processes. Using the human endometrial cancer cell lines Hec 1A and Hec 1B as model systems, we have investigated the effects of E2 and Tam on endometrial nongenomic signaling, cytoskeletal remodeling, and cell motility. Results indicate that both E2 and Tam triggered rapid activation of ERK1/2, c-Src, and focal adhesion kinase signaling pathways and filamentous actin cytoskeletal changes. These changes included dissolution of stress fibers, dynamic actin accumulation at the cell periphery, and formation of lamellipodia, filopodia, and membrane spikes. Longer treatments with either agent induced cell migration in wound healing and Boyden chamber assays. Agent-induced cytoskeletal remodeling and cell migration were blocked by a Src inhibitor. These findings define cytoskeletal remodeling and cell migration as processes regulated by E2 and 4-hydroxytamoxifen nongenomic signaling in endometrial cancer. This new information may serve as the foundation for the development of new clinical therapeutic strategies.
Overexpression of Kruppel-Like Factor 7 Regulates Adipocytokine Gene Expressions in Human Adipocytes and Inhibits Glucose-Induced Insulin Secretion in Pancreatic β-Cell Line
Authors: Kawamura Yoshihiro , Tanaka Yasushi , Kawamori Ryuzo , Maeda Shiro
Published: December 2005

We have identified Kruppel-like factor 7 (KLF7) as a new candidate for conferring susceptibility to type 2 diabetes. To ascertain the possible involvement of KLF7 in the pathogenesis of type 2 diabetes, we examined the functional roles of KLF7 in various types of cells. In human adipocytes overexpressing KLF7, the expression of adiponectin and leptin was decreased compared with that in control cells, whereas expression of IL-6 was increased. In the insulin-secreting cell line (HIT-T15 cells), the expression and glucose-induced secretion of insulin were significantly suppressed in KLF7-overexpressed cells compared with control cells, accompanied by the reduction in the expression of glucose transporter 2, sulfonylurea receptor 1, Kir6.2, and pancreatic-duodenal homeobox factor 1. We also found that the overexpression of KLF7 resulted in the decrease of hexokinase 2 expression in smooth muscle cells, and of glucose transporter 2 expression in the HepG2 cells. These results suggest that KLF7 may contribute to the pathogenesis of type 2 diabetes through an impairment of insulin biosynthesis and secretion in pancreatic β-cells and a reduction of insulin sensitivity in peripheral tissues. Therefore, we suggest that KLF7 plays an important role in the pathogenesis of type 2 diabetes, and may be a useful target for new drugs to aid in the prevention and treatment of this disease.
Regulation of Macrophage Inflammatory Gene Expression by the Orphan Nuclear Receptor Nur77
Authors: Pei Liming , Castrillo Antonio , Tontonoz Peter
Published: December 2005

Members of the nuclear hormone receptor superfamily have emerged as important regulators of macrophage gene expression in inflammation and disease. Previous studies have shown that the lipid-activated receptors peroxisomal proliferator-activated receptor and liver X receptor inhibit nuclear factor-κB (NF-κB) signaling and inflammatory gene expression. We recently identified the NR4A subfamily of orphan nuclear receptors (Nur77/NR4A1, Nurr1/NR4A2, and NOR1/NR4A3) as lipopolysaccharide- and NF-κB-responsive genes in macrophages. However, the role of these transcription factors in macrophage gene expression is unknown. We demonstrate here that, in contrast to peroxisomal proliferator-activated receptor and liver X receptor, the role of NR4A receptors in macrophages is proinflammatory. Retroviral expression of Nur77 in macrophages leads to the transcriptional activation of multiple genes involved in inflammation, apoptosis, and cell cycle control. One particularly interesting Nur77-responsive gene is the inducible kinase IKKi/IKKε, an important component of the NF-κB signaling pathway. The IKKi promoter contains a functional NR4A binding site and is activated by all three NR4A receptors in transient transfection assays. Consistent with the activation of IKKi, expression of Nur77 in macrophages potentiates the induction of inflammatory gene expression in response to lipopolysaccharide. These results identify a new role for NR4A orphan nuclear receptors in the control of macrophage gene expression during inflammation.
Repulsive Separation of the Cytoplasmic Ends of Transmembrane Helices 3 and 6 Is Linked to Receptor Activation in a Novel Thyrotropin Receptor Mutant (M626I)
Authors: Ringkananont Usanee , Van Durme Joost , Montanelli Lucia , Ugrasbul Figen , Yu Y. Miles , Weiss Roy E. , Refetoff Samuel , Grasberger Helmut
Published: December 2005

Ligand-dependent activation of G protein-coupled receptors (GPCRs) involves repositioning of the juxtacytoplasmic ends of transmembrane helices TM3 and TM6. This concept, inferred from site-directed spin labeling studies, is supported by chemical cross-linking of the cytoplasmic ends of TM3 and TM6 blocking GPCR activation. Here we report a novel constitutive active mutation (M626I) in TM6 of the TSH receptor (TSHR), identified in affected members of a family with nonautoimmune hyperthyroidism. The specific constitutive activity of M626I, measured by its basal cAMP generation corrected for cell surface expression, was 13-fold higher than that of wild-type TSHR. Homology modeling of the TSHR serpentine domain based on the rhodopsin crystal structure suggests that M626 faces the side chain of I515 of TM3 near the membrane-cytoplasmic junction. Steric hindrance of the introduced isoleucine by I515 is consistent with the fact that shorter or more flexible side chains at position 626 did not increase constitutivity. Furthermore, a reciprocal mutation at position 515 (I515M), when introduced into the M626I background, acts as revertant mutation by allowing accommodation of the isoleucine sidechain at position 626 and fully restoring the constitutive activity to the level of wild-type TSHR. Thus, repulsive separation of the juxtacytoplasmic TM6 and TM3 in the M626I model conclusively demonstrates a direct link between the opening of this cytoplasmic face of the receptor structure and G protein coupling.
Sequence-Specific Deoxyribonucleic Acid (DNA) Recognition by Steroidogenic Factor 1: A Helix at the Carboxy Terminus of the DNA Binding Domain Is Necessary for Complex Stability
Authors: Little Tanya H. , Zhang Yongbo , Matulis Christina K. , Weck Jennifer , Zhang Zhipeng , Ramachandran Aparna , Mayo Kelly E. , Radhakrishnan Ishwar
Published: December 2005

Steroidogenic factor 1 (SF1) is a member of the NR5A subfamily of nuclear hormone receptors and is considered a master regulator of reproduction because it regulates a number of genes encoding reproductive hormones and enzymes involved in steroid hormone biosynthesis. Like other NR5A members, SF1 harbors a highly conserved approximately 30-residue segment called the FTZ-F1 box C-terminal to the core DNA binding domain (DBD) common to all nuclear receptors and binds to 9-bp DNA sequences as a monomer. Here we describe the solution structure of the SF1 DBD in complex with an atypical sequence in the proximal promoter region of the inhibin-α gene that encodes a subunit of a reproductive hormone. SF1 forms a specific complex with the DNA through a bipartite motif binding to the major and minor grooves through the core DBD and the N-terminal segment of the FTZ-F1 box, respectively, in a manner previously described for two other monomeric receptors, nerve growth factor-induced-B and estrogen-related receptor 2. However, unlike these receptors, SF1 harbors a helix in the C-terminal segment of the FTZ-F1 box that interacts with both the core DBD and DNA and serves as an important determinant of stability of the complex. We propose that the FTZ-F1 helix along with the core DBD serves as a platform for interactions with coactivators and other DNA-bound factors in the vicinity.
Comparative overwintering physiology of Alaska and Indiana populations of the beetle Cucujus clavipes (Fabricius): roles of antifreeze proteins, polyols, dehydration and diapause
Authors: Bennett Valerie A. , Sformo Todd , Walters Kent , Toien Oivind , Jeannet Kennan , Hochstrasser Ronald , Pan Qingfeng , Serianni Anthony S. , Barnes Brian M. , Duman John G.
Published: December 2005

The beetle Cucujus clavipes is found in North America over a broad latitudinal range from North Carolina (latitude ∼35°N) to near tree line in the Brooks Range in Alaska (latitude, ∼67°30′ N). The cold adaptations of populations from northern Indiana (∼41°45′N) and Alaska were compared and, as expected, the supercooling points (the temperatures at which they froze) of these freeze-avoiding insects were significantly lower in Alaska insects. Both populations produce glycerol, but the concentrations in Alaska larvae were much higher than in Indiana insects(∼2.2 and 0.5 mol l–1, respectively). In addition, both populations produce antifreeze proteins. Interestingly, in the autumn both populations have the same approximate level of hemolymph thermal hysteresis,indicative of antifreeze protein activity, suggesting that they synthesize similar amounts of antifreeze protein. A major difference is that the Alaska larvae undergo extreme dehydration in winter wherein water content decreases from 63–65% body water (1.70–1.85 g H2O g–1 dry mass) in summer to 28–40% body water(0.40–0.68 g H2O g–1 dry mass) in winter. These 2.5–4.6-fold reductions in body water greatly increase the concentrations of antifreeze in the Alaska insects. Glycerol concentrations would increase to 7–10 mol l–1 while thermal hysteresis increased to nearly 13°C (the highest ever measured in any organism) in concentrated hemolymph. By contrast, Indiana larvae do not desiccate in winter. The Alaska population also undergoes a diapause while insects from Indiana do not. The result of these, and likely additional, adaptations is that while the mean winter supercooling points of Indiana larvae were approximately –23°C, those of Alaska larvae were –35 to–42°C, and at certain times Alaska C. clavipes did not freeze when cooled to –80°C.
Prediction of kinetics and kinematics of running animals using an analytical approximation to the planar spring-mass system
Authors: Robilliard Justine J. , Wilson Alan M.
Published: December 2005

The spring-mass model is often used to describe bouncing gaits. Although at first inspection the mechanical system appears simple, the solution to the motion cannot be derived easily. An analytical solution would provide a fast and intuitive method to determine the kinetic and kinematics of the centre of mass of terrestrial animals during over-ground steady state locomotion. Here,an analytical approximation using sine wave simplifications for the motion is presented. The analytical solution was almost indistinguishable from the numerical solution across initial leg angles of 17.5–30°; percentage differences between the analytical solution and the numerical solution were less than 1% for total mechanical energy, centre of mass position, total limb compression and centre of mass velocity and less than 2% different for resultant limb force and vertical acceleration of the centre of mass. The solution matched the relationship between stance time and speed collected from a trotting racehorse and accurately characterised previously published biological data. This study has shown that a simple analytical solution can predict the kinetics and kinematics of a spring-mass system over the range of biologically relevant sweep angles and horizontal velocities, and could be used to further understanding of limb deployment and gait selection. Using this analytical solution not only the force profile but also the changes in mechanical energy can be calculated from easily observed morphological and kinematic data.
Plant senescence cues entry into diapause in the gall flyEurosta solidaginis: resulting metabolic depression is critical for water conservation
Authors: Williams Jason B. , Lee Richard E.
Published: December 2005

Mechanisms and possible cues for seasonal increases in desiccation resistance in larvae of the goldenrod gall fly Eurosta solidaginis,were examined before and after natural and premature plant senescence, or after being removed from their gall and placed in either 100, 95 or 75%relative humidity (RH). Rates of water loss were 8.6-fold lower, averaging 0.7±0.2 μg mm–2 h–1, in larvae from senescent gall tissue and after all RH treatments than in control larvae from pre-senescent plants. Enhanced desiccation resistance occurred quickly,within 3 days of removal from their gall. Contrary to most previous reports, a large majority of the increased desiccation resistance (∼85%) was due to reduced respiratory transpiration with the remainder being the result of a lowered cuticular permeability. Rates of cuticular water loss were reduced by the presence of a vapor pressure gradient between the larval hemolymph and environmental water vapor and were probably due to increases in cuticular lipids and/or production of the cryoprotectant glycerol. Metabolic rate was reduced by over fourfold, averaging 0.07±0.01 μl CO2g–1 h–1, in larvae from senescent gall tissue and all RH treatments compared to larvae from pre-senescent plants. The magnitude of the reduction in metabolic rates indicated that these larvae had entered diapause. In addition, larvae entered diapause in response to removal from, or degeneration of, the gall tissue they feed, on rather than seasonal changes in temperature or photoperiod. The low metabolic rates of the diapausing larvae probably allowed them to dramatically reduce their respiratory transpiration and total rate of water loss compared with non-diapausing controls. Thus, diapause, with its associated lowered metabolic rate, may be essential for conserving water in overwintering temperate insects, which may be dormant for six or more months of the year.
Ontogeny of bone strain: the zygomatic arch in pigs
Authors: Herring Susan W. , Pedersen Scott C. , Huang Xiaofeng
Published: December 2005

At the time of weaning, infant animals have little experience with hard food, and thus their skulls are not likely to be epigenetically adapted for the loads imposed by mastication. We examined bone strain in the zygomatic arch of 4-week-old weanling piglets. Functional strains in piglets differed from those previously reported for older pigs in that the squamosal bone was not bent in the horizontal plane and the principal tensile strain on the zygomatic bone did not correspond to the direction of masseter muscle pull. Strain patterns were more variable in piglets than in older pigs. In older pigs, masticatory strains can be reproduced by stimulating the masseter muscles. When the piglet masseter was stimulated, strain patterns were more similar to those of older pigs, but shear strain magnitudes were the largest yet recorded from mammalian skull bones, up to 4000 μϵ. To put these findings in the context of skeletal adaptation, 45 dry skulls, including some animals from the strain study, were measured. Reduced major axis regressions indicated that the infant arch was rounder in cross section and straighter than that of older animals. With growth, the arch became dorsoventrally higher, while mediolateral thickness decreased in the squamosal bone. Overall,these changes should make strain more predictable, explaining the lower variability in older animals. Other factors likely to be important in causing unique strain regimes in piglets include (1) unfamiliarity with hard food, (2)greater importance of muscles other than the same-side masseter and (3)greater proximity of molariform teeth to the arch. Collectively, these data indicate that the skeleton is not pre-adapted for specific functional loads.
Acute thermal stress and various heavy metals induce tissue-specific pro-or anti-apoptotic events via the p38-MAPK signal transduction pathway in Mytilus galloprovincialis (Lam.)
Authors: Kefaloyianni Erene , Gourgou Eleni , Ferle Vanessa , Kotsakis Efstathios , Gaitanaki Catherine , Beis Isidoros
Published: December 2005

We investigated the effects of various heavy metals such as copper, zinc and cadmium, as well as acute thermal stress, on the signalling mechanisms involved in the protection and/or apoptosis of Mytilus galloprovincialis mantle and gill tissues. The results of our studies revealed that mantle and gill tissues differentially respond to the stressful stimuli examined. In the mantle tissue, 1 μmol l–1Cu2+ and 50 μmol l–1 Zn2+ induced a transient p38-MAPK activation, whereas 1 μmol l–1Cd2+ induced a biphasic profile of the kinase phosphorylation with maximal values at 15 and 120 min of treatment, respectively. Furthermore, 1μmol l–1 SB203580 abolished the Cu2+-induced kinase phosphorylation. In gills, both Cu2+ and Zn2+induced a considerably higher p38-MAPK activation, which remained elevated for at least 60 min, whereas Cd2+ induced a maximal kinase activation within 60 min of treatment. Hypothermia (4°C) induced a moderate kinase phosphorylation (maximised at 30 min), whereas hyperthermia (30°C) induced a rapid (within 15 min) p38-MAPK phosphorylation that remained considerably above basal levels for at least 2 h. Our studies on the synergistic effect of hyperthermia and Cu2+ revealed that these two stressful stimuli are additive in the mantle tissue, inducing an almost double p38-MAPK activation. Further studies on the involvement of the p38-MAPK signalling pathway in tissue-specific pro- or anti-apoptotic events revealed that identical stressful stimuli possibly lead to apoptotic death via the caspase-3 activation in the mantle tissue and to anti-apoptotic events possibly via the induction of Hsp70 overexpression in the gill tissue.
Chromatic interaction between egg pigmentation and skin chromatophores in the nuptial coloration of female two-spotted gobies
Authors: Svensson Per Andreas , Forsgren Elisabet , Amundsen Trond , Sköld Helen Nilsson
Published: December 2005

In two-spotted gobies (Gobiusculus flavescens Fabricius 1779),females develop an orange belly as they approach sexual maturity. Bright belly coloration is preferred by males and has been suggested to act as a female ornament. This coloration is unusual in that it originates partly from pigmentation of the abdominal skin but also from strongly pigmented gonads directly visible through the skin. In addition, females have been observed to temporarily become more colourful during courtship and competition. To understand how gonad and skin pigmentation interact in this nuptial coloration, the potential for colour modification via regulation of skin chromatophores was investigated. Noradrenaline caused aggregation of chromatophore pigment and was used to experimentally reduce the contribution of skin chromatophores to the nuptial coloration. Chromatophore pigment aggregation caused bellies to become less colourful and abdominal skin biopsies to become less colourful and more transparent. There was a strong positive relationship between belly coloration and the coloration of the underlying gonads. This shows that belly coloration honestly reflects egg pigmentation, mainly because the transparency of the abdominal skin allows other fish to see the gonads directly. Interestingly, when noradrenaline caused pigment to aggregate and thereby increased the transparency of the skin, the relationship between belly and gonad coloration weakened. We conclude that female G. flavescens have a potential to use skin chromatophores to rapidly alter their nuptial coloration, thereby affecting the efficacy with which information about gonad coloration is conveyed.
Clinically Related Protein–Peptide Interactions Monitored in Real Time on Novel Peptide Chips by Surface Plasmon Resonance Imaging
Authors: Cherif Boutheina , Roget André , Villiers Christian L , Calemczuk Roberto , Leroy Vincent , Marche Patrice N , Livache Thierry , Villiers Marie-Bernadette
Published: December 2005

Background: Developing rapid, high-throughput assays for detecting and characterizing protein–protein interactions is a great challenge in the postgenomic era. We have developed a new method that allows parallel analysis of multiple analytes in biological fluids and is suitable for biological and medical studies.

Methods: This technology for studying peptide–antibody interactions is based on polypyrrole-peptide chips and surface plasmon resonance imaging (SPRi). We generated a chip bearing a large panel of peptide probes by successive electro-directed copolymerizations of pyrrole–peptide conjugates on a gold surface.

Results: We provide evidence that (a) the signal produced by antibody binding is highly specific; (b) the detected signal specifically reflects the antibody concentration of the tested solution in a dose-dependent manner; (c) this technique is appropriate for analyzing complex media such as undiluted sera, a novelty with respect to previous techniques; and (d) correlation between classic ELISA results and the SPRi signal is good (P = 0.008). We also validated this system in a medical model by detecting anti-hepatitis C antibodies in patient-derived sera.

Conclusion: Because of its characteristics (easy preparation of the peptide chip; high-throughput, label-free, real-time detection; high specificity; and low background), this technology is suitable for screening biological samples and for large-scale studies.
6S RNA – an ancient regulator of bacterial RNA polymerase rediscovered
Authors: Willkomm Dagmar K. , Hartmann Roland K.
Published: December 2005

The bacterial riboregulator 6S RNA was one of the first non-coding RNAs to be discovered in the late 1960s, but its cellular role remained enigmatic until the year 2000. 6S RNA, only recognized to be ubiquitous among bacteria in 2005, binds to RNA polymerase in a σ factor-dependent manner to repress transcription from a subgroup of promoters. The common feature of a double-stranded rod with a central bulge has led to the proposal that 6S RNA may mimic an open promoter complex.
Chemical procedure applied for the identification of Rf/Db produced in the 48Ca +243Am reaction
Authors: Schumann Dorothea
Published: December 2005

A chemical separation procedure for Rf/Db is described which was applied to a long-lived decay product from the nuclear fusion reaction 48Ca+ 243Am. A 1.2 mg thick 243Am target was bombarded by 247 MeV 48Ca particles. The recoiling products were collected in a thick Cu catcher for about one day and then subjected to a chemical separation procedure that included an ion exchange from dilute HF solutions. Final samples were prepared on 30 μg/cm2 thick polyethylene (PE) foils and counted in 4π-geometry for α-particles and spontaneous fission (SF) coincidences. The detector arrays were surrounded by 3He detectors to also assay prompt neutrons. Decontamination factors from actinides of about 105 were achieved. Group 6 (W) to 14 (Pb) elements as models for their heavier homologues were shown to be separated from the Rf/Db fraction with more than 90%. In eight final samples, representing a total beam dose of 3.4 × 1018 particles, 15 SF events were detected. The decay pattern points to a single component with a half-life of ≈32h, which shows a chemical behavior similar to the lighter homologues of group 4 and 5 elements.
Complexation of Cm(III)/Eu(III) with silicates in basic solutions
Authors: Wang Zheming , Felmy Andrew R. , Xia Y. X. , Qafoku O. , Yantassee W. , Cho H.
Published: December 2005

The complexation of Cm(III) and Eu(III) with dissolved silica was studied by solubility measurement and time resolved laser fluorescence spectroscopy (TRLFS) in basic solutions over a range of total silica concentrations and ionic strengths (NaNO3). In initial experiments on the solubility of Eu(OH)3 in silicate containing solutions we observed a rapid increase in the soluble Eu(III) concentration under basic conditions. The Eu(III)/Cm(III) silicate complexes that formed caused a significant increase of the hypersensitive 5
D
0 → 2
F
2 band around 615 nm relative to the non-hypersensitive 5
D
0 → 7
F
1 band at 592 nm for Eu(III). Further studies of Eu(III) and Cm(III) containing solutions showed a shift of the fluorescence spectral maximum from 594 nm to up to 607 nm for Cm(III) along with a significant increase of fluorescence intensities. The fluorescence lifetimes for Eu(III) species increased from 115 μs to 1.8 ms in 3.0 M and 5.0 M NaNO3, corresponding to full coordination, and from 68 μs to 202 μs for Cm(III) in 0.1 M NaNO3, consistent with the removal of 6–7 water molecules upon silicate complexation. The variations of the fluorescence intensity and the concentrations of the monomeric and polymeric silicates suggested that in basic silicate solutions, Eu(III)/Cm(III) mainly complexes with polysilicates.
Americium and curium deposition in Finland from the Chernobyl accident
Authors: Salminen Susanna , Paatero J. , Jaakkola T. , Lehto Jukka
Published: December 2005

241Am and 244Cm were analysed from peat samples collected in Finland immediately after the Chernobyl accident. The separation method included co-precipitation, anion exchange and extraction chromatography. Activities of 241Am and 244Cm were measured by alpha spectrometry. The activity of Chernobyl-derived 241Am varied between 0.0115 and 9.32 Bq/m2 and that of 244Cm from < 0.002 to 1.97 Bq/m2 (reference date 1.5.1986). The origin of 241Am in Finland is predominantly from atmospheric nuclear tests. However, the geographical distribution of Chernobyl-americium is uneven and depending on a location even 100% of 241Am in peat originated from the Chernobyl accident. The deposition pattern of Chernobyl-derived 241Am and 244Cm resembles that of other refractory nuclides, such as 95Zr, 141Ce and 239,240Pu.