bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel role for Notch ligand Delta-1 as a regulator of human Langerhans cell development from blood monocytes
Authors: Hoshino Natsuki , Katayama Naoyuki , Shibasaki Tetsunori , Ohishi Kohshi , Nishioka Junji , Masuya Masahiro , Miyahara Yoshihiro , Hayashida Masahiko , Shimomura Daiki , Kato Takuma , Nakatani Kaname , Nishii Kazuhiro , Kuribayashi Kagemasa , Nobori Tsutomu , Shiku Hiroshi
Published: July 2005

Human Langerhans cells (LCs) are of hematopoietic origin, but cytokine regulation of their development is not fully understood. Notch ligand Delta-1 is expressed in a proportion of the skin. Granulocyte-macrophage colony-stimulating factor (GM-CSF) and transforming growth factor-β1 (TGF-β1) are also secreted in the skin. We report here that Delta-1, in concert with GM-CSF and TGF-β1, induces the differentiation of human CD14+ blood monocytes into cells that express LC markers: CD1a, Langerin, cutaneous lymphocyte-associated antigen, CC chemokine receptor 6, E-cadherin, and Birbeck granules. The resulting cells display phagocytic activity and chemotaxis to macrophage inflammatory protein-1α (MIP-1α). In response to CD40 ligand and tumor necrosis factor α, the cells acquire a mature phenotype of dendritic cells that is characterized by up-regulation of human leukocyte antigen (HLA)-ABC, HLA-DR, CD80, CD86, CD40, and CD54 and appearance of CD83. These cells in turn show chemotaxis toward MIP-1β and elicit activation of CD8+ T cells and T helper cell type 1 polarization of CD4+ T cells. Thus, blood monocytes can give rise to LCs upon exposure to the skin cytokine environment consisting of Delta-1, GM-CSF, and TGF-β1, which may be, in part, relevant to the development of human epidermal LCs. Our results extend the functional scope of Notch ligand δ-1 in human hematopoiesis.
The Adapter Protein GRB10 Is an Endogenous Negative Regulator of Insulin-Like Growth Factor Signaling
Authors: Dufresne Aimee M. , Smith Robert J.
Published: July 2005

The growth factor IGF-I is critical for normal human somatic growth and development. Growth factor receptor-bound protein (Grb)10 is a protein that interacts with the IGF-I receptor and may thus regulate IGF-I-stimulated growth. However, the role of endogenous Grb10 in regulating IGF-I action is not known. The objective of this study was to determine the function of endogenous Grb10 in IGF signaling responses. Using small interfering RNA, we demonstrate that knockdown of Grb10 enhances IGF-I-mediated phosphorylation of insulin receptor substrate proteins, Akt/protein kinase B, and ERK1/2 and leads to a corresponding increase in DNA synthesis. Although IGF-I receptor autophosphorylation normally correlates with receptor signaling, we demonstrate a decrease in IGF-I-stimulated receptor phosphorylation in Grb10 knockdown cells. Pretreatment of cells with the protein-tyrosine phosphatase inhibitor pervanadate partially reverses this effect of Grb10 knockdown on receptor phosphorylation, indicating that endogenous Grb10 may block phosphatase access to the activated IGF-I receptor. Marked small interfering RNA knockdown of Grb10 does not result in increased or decreased expression of the related proteins Grb7 or Grb14. As further evidence for Grb10 functional specificity, the recently identified Grb10 interacting GYF proteins are shown to interact specifically with Grb10 and not with Grb7 or Grb14, using yeast two-hybrid assays. We conclude that Grb10 functions as a specific endogenous suppressor of IGF-I-stimulated cell signaling and DNA synthesis. Modulation of the Grb10-IGF-I receptor pathway may represent a mechanism that regulates IGF-I-responsive cell and tissue growth.
ObRa and ObRe Are Differentially Expressed in Adipose Tissue in Aged Food-Restricted Rats: Effects on Circulating Soluble Leptin Receptor Levels
Authors: Gallardo Nilda , Arribas Carmen , Villar Margarita , Ros Manuel , Carrascosa José M. , Martínez Carmen , Andrés Antonio
Published: July 2005

In rodents, soluble leptin receptor (SLR) may be generated by alternative splicing of ObR mRNA and/or as a cleavage product of ObR membrane-anchored receptors. In this study, we investigated the contribution of both processes on the generation of SLR in 3-, 8-, and 24-month-old Wistar rats fed ad libitum (AL) or under food restriction (FR). To this end, we determined serum SLR levels and analyzed ObRa and ObRe mRNA expression under these physiological conditions. Additionally, we studied the cellular distribution of ObRa and the generation of SLR by N-ethyl-maleimide-induced shedding from ObRa membrane receptors in isolated adipocytes. Serum SLR levels were significantly increased in 8- and 24-month-old rats under FR, whereas similar amounts were found in rats of different ages fed AL. ObRa and ObRe mRNA expression in epididymal adipose tissue increased with aging. In contrast, after FR, ObRe mRNA expression decreased, whereas ObRa mRNA expression further increased compared with 8- and 24-month-old rats fed AL. Additionally, FR promoted a change in the distribution of ObRa between internal and plasma membranes in isolated adipocytes, increasing its presence at the cell surface. Finally, the generation of SLR by N-ethyl-maleimide-induced shedding from ObRa was also increased under FR. These data suggest that shedding of ObRa membrane-anchored receptors, rather than ObRe expression, might preferentially contribute to the generation of the increased levels of SLR in serum under conditions of FR.
Insulin-Like Growth Factor-I Receptor Signaling in Tamoxifen-Resistant Breast Cancer: A Supporting Role to the Epidermal Growth Factor Receptor
Authors: Knowlden J. M. , Hutcheson I. R. , Barrow D. , Gee J. M. W. , Nicholson R. I.
Published: July 2005

There is considerable evidence that the epidermal growth factor receptor (EGFR) and IGF-I receptor (IGF-IR) cross-talk in breast cancer cells. In the present study, we have examined whether EGFR/IGF-IR cross-talk exists in EGFR-positive tamoxifen-resistant variants of MCF-7 (Tam-R) and T47D (T47D-R) breast cancer cell lines. Although Tam-R cells expressed reduced IGF-IR protein levels compared with their wild-type MCF-7 counterparts, phosphorylated IGF-IR protein levels were equivalent in the two cell lines under basal growth conditions, possibly as a consequence of increased IGF-II expression in Tam-R cells. IGF-II activated both IGF-IR and EGFR in Tam-R cells, whereas only activation of IGF-IR was observed in wild-type cells. In contrast, epidermal growth factor rapidly induced EGFR, but not IGF-IR, phosphorylation in Tam-R cells. IGF-II promoted direct association of c-SRC with IGF-IR, phosphorylated c-SRC, and increased EGFR phosphorylation at tyrosine 845, a c-SRC-dependent phosphorylation site. Pretreatment with either AG1024 (IGF-IR-specific inhibitor) or an IGF-II neutralizing antibody inhibited basal IGF-IR, c-SRC, and EGFR phosphorylation, and AG1024 significantly reduced Tam-R basal cell growth. The c-SRC inhibitor SU6656 also inhibited growth, reduced basal and IGF-II-induced c-SRC and EGFR phosphorylation, and blocked EGFR activation by TGFα. Similarly, in T47D-R cells, AG1024 and SU6656 inhibited basal and IGF-II-induced phosphorylation of c-SRC and EGFR, and SU6656 reduced TGFα-induced EGFR activity. These results suggest the existence of a unidirectional IGF-IR/EGFR cross-talk mechanism whereby IGF-II, acting through the IGF-IR, regulates basal and ligand-activated EGFR signaling and cell proliferation in a c-SRC-dependent manner in Tam-R cells. This cross-talk between IGF-IR and EGFR is not unique to Tam-R cells because this mechanism is also active in a tamoxifen-resistant T47D-R cell line.
Expression of Insulin-Like Factor 3 Protein in the Rat Testis during Fetal and Postnatal Development and in Relation to Cryptorchidism Induced by in Utero Exposure to Di (n-Butyl) Phthalate
Authors: McKinnell Chris , Sharpe Richard M. , Mahood Kim , Hallmark Nina , Scott Hayley , Ivell Richard , Staub Christophe , Jégou Bernard , Haag Friedrich , Koch-Nolte Friedrich , Hartung Stefan
Published: July 2005

Cryptorchidism is a common reproductive abnormality, possibly resulting from abnormal hormone production/action by the fetal testis. Insulin-like factor 3 (Insl3) is thought to be involved in gubernaculum development and transabdominal testicular descent, but its importance is unclear, due partly to lack of suitable Insl3 antibodies. We generated (by genetic immunization) and validated a novel antirat Insl3 antibody, which we used to characterize immunoexpression of Insl3 in rat Leydig cells (LCs) from fetal life until adulthood and its relationship to cryptorchidism. Immunoexpression was strong on embryonic day (E) 17.5 and E19.5 and from 35 d of age onward but weak from E21.5 until puberty. Because in utero exposure to di (n-butyl) phthalate (DBP) induces cryptorchidism and suppresses Insl3 gene expression, we investigated Insl3 protein expression in fetal and adult rats exposed to 500 mg/kg·d DBP from E13.5 to E21.5. Expression on E17.5 and E19.5 decreased dramatically after DBP exposure, but there was no consistent correlation between this suppression and abnormal testis position. We also compared expression of Insl3 and P450 side-chain cleavage enzyme in fetal testes from rats exposed in utero to DBP or flutamide (50 mg/kg·d). DBP treatment suppressed expression of both P450 side-chain cleavage enzyme and Insl3 at E19.5, but flutamide exposure had no effect on either protein, demonstrating that Insl3 expression in fetal rat LCs is not androgen regulated. In adult rats, Insl3 expression was suppressed in 80% of cryptorchid and 50% of scrotal testes from rats exposed to DBP, suggesting that prenatal DBP exposure also leads to maldevelopment/malfunction of the adult LC population in some animals.
Groningen valve change in difficult cases
Authors: Jain A , Parker A J
Published: July 2005

A difficult Groningen valve change is one of the problems frequently encountered in the post-laryngectomy patient. A safe and simple technique for this procedure is described.
B-cell lymphoma of the larynx in a patient with rheumatoid arthritis
Authors: Patiar S , Ramsden J D , Freeland A P
Published: July 2005

We report a case of B-cell lymphoma with the larynx as the primary site of presentation in a rheumatoid arthritis patient previously treated with methotrexate. Primary non-Hodgkin’s lymphoma (NHL) of the larynx is rare. There may be an increased risk of lymphoma in patients with rheumatoid arthritis, with an even higher risk in those patients treated with methotrexate. The diagnostic and treatment options are discussed.
Results of inlay cartilage myringoplasty in terms of closure of central tympanic membrane perforations
Authors: Effat Kamal G
Published: July 2005

There is a current effort to perform myringoplasty for tympanic membrane perforations as a day-stay procedure. In 1998, an inlay myringoplasty using tragal cartilage/perichondrium was described. A retrospective study was performed by the author to analyse the results of inlay carilage myringoplasty, in terms of closure of simple perforations of the tympanic membrane. The results of a control group of previous cases of underlay temporalis fascia myringoplasty were retrieved from the hospital records. All the operations in both groups were performed by the same author at the same institution. The operation of inlay cartilage butterfly myringoplasty has been performed in 28 ears with simple central tympanic membrane perforations. Inconsistent results have been obtained, in that only 43 per cent showed closure of the perforation at the most recent follow-up. A control group of standard underlay temporalis fascia myringoplasty has been performed by the same author in 23 ears. Eighty-three per cent of the perforations were closed at the last follow-up. The difference is statistically highly significant (p < 0.01).
Are adjuvant therapies for tonsillectomy evidence based?
Authors: Dhiwakar M , Brown P M
Published: July 2005

Our aim was to ascertain the current practice of adjuvant therapy for tonsillectomy and to determine whether it is evidence based. Anonymized postal questionnaires were sent to all UK otolaryngology consultants registered with the specialty association, and a literature search was performed
using relevant search terms in all possible combinations. Among the responders there was little enthusiasm for routine intra-operative local anaesthesia, post-operative topical benzydamine hydrochloride (Difflam) spray or post-operative antibiotics. This is consistent with the lack of robust
evidence to support any of these practices. Paracetamol (acetaminophen) is prescribed by almost 90 per cent for post-operative analgesia, and the current literature supports its efficacy and safety. Further, most practitioners combine paracetamol with opioids and/or non-steroidal anti-inflammatory
drugs (NSAIDs). Evidence to support the additional use of these agents is, however, non-existent or limited. Some aspects of tonsillectomy care are uniform and evidence based. Others are heterogeneous and suffer from lack of adequate data in the literature.
Presurgical, ultrasound-guided anchor-wire marking of impalpable cervical lymph nodes
Authors: Bryant J A , Siddiqi N J , Loveday E J , Irvine G H
Published: July 2005

This case illustrates the surgical use of wire localization, a well tried technique from a different field of surgery, in the removal of an ultrasound-detected, impalpable deep lower cervical lymph node in a high-risk patient. A localization needle with an echogenic tip was placed freehand
under ultrasound guidance, immediately before surgery. The imaging and marking of the impalpable cervical lymph node resulted in a precise surgical dissection and a reduction in operating time whilst minimizing risks to the patient and staff.
Effect of thermal energy produced by drilling on the facial nerve: histopathologic evaluation in guinea pigs
Authors: Aslan Asim , Vatansever H Seda , Aslan Gulay Guclu , Eskiizmir Gorkem , Giray Gulsen
Published: July 2005

The effect of thermal energy due to drilling around the facial nerve canal on the facial nerve was histopathologically evaluated in four guinea pigs. The bony canal of the facial nerve was drilled using a 3mm diamond burr for one minute. The temperature changes on the facial nerve canalwere noted before and after dissection. The temporal bones of the animals were histopathologically examined under light microscopy using haematoxylin & eosin (H&E) and solochrome cyanine staining for myelin, and immunohistochemical staining for neuronal nitric oxide synthase (nNOS). Compared to the control group, it was observed with H&E staining that there was oedema among the axonal fibres and with solochrome cyanine staining that the thickness of the myelin fibres was decreased, and that the severity and extent of nNOS activity was decreased in the axonal fibres. It was concluded that a temperature increase on the facial canal may potentially lead to inflammation of the nerve, and may also cause deterioration of nerve conduction to some extent.
Large B-cell non-Hodgkin’s lymphoma presenting as a laryngeal cyst
Authors: Agada F O , Mistry D , Grace A R H , Coatesworth A P
Published: July 2005

Cystic lesions of the larynx are most commonly benign. However, we report a case of non-Hodgkin’s lymphoma (NHL) of the larynx which presented as a supraglottic cyst. This form of presentation has not been previously described in the medical literature.
Liposarcoma of the retropharyngeal space
Authors: Gundelach Raefe , Ullah Ramzan , Coman Scott , Campbell Kate
Published: July 2005

Liposarcoma is a common soft tissue malignancy that occurs infrequently in the head and neck. Liposarcoma of the retropharynx is exceptionally rare, only four cases being described in the literature. We present a case in which retropharyngeal liposarcoma occurred in a patient who had had multiple previous subcutaneous lipomas excised. This paper explores this very unusual presentation and discusses the difficulties in the diagnosis and management of this rare tumour.
Serum Parathyroid Hormone Concentrations Are Increased in Women with Polycystic Ovary Syndrome
Authors: Panidis Dimitrios , Balaris Christos , Farmakiotis Dimitrios , Rousso David , Kourtis Anargyros , Balaris Vassilios , Katsikis Ilias , Zournatzi Vassiliki , Diamanti-Kandarakis Evanthia
Published: July 2005

Background: The present study was designed to investigate the effects of polycystic ovary syndrome (PCOS) and of obesity on serum parathyroid hormone (ΡΤΗ), 25-hydroxyvitamin D (25-OH-vitamin D), and 1,25-dihydroxyvitamin D [1,25-(OH)2-vitamin D] concentrations and the possible associations of the above calciotropic hormones with the hormonal and metabolic characteristics of the syndrome.

Methods: We studied 58 obese [body mass index (BMI) >30 kg/m2] women with PCOS, 64 overweight (ΒΜI, 25–30 kg/m2) women with the syndrome, 169 normal-weight (BMI <25 kg/m2) women with PCOS, 29 obese controls (ovulatory women without clinical or biochemical hyperandrogenemia), 14 overweight controls, and 70 normal-weight controls. Blood samples were collected (at 0900 after an overnight fast) between the 3rd and 6th days of a menstrual cycle in the control groups and during a spontaneous bleeding episode in the PCOS groups. Circulating concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin (PRL), testosterone, Δ4-androstenedione, 17α-hydroxyprogesterone, sex-hormone–binding globulin (SHBG), insulin, glucose, PTH, 25-OH-vitamin D, and 1,25-(OH)2-vitamin D were measured.

Results: Both PCOS and increased body weight had a significant positive effect on serum PTH values. PTH concentrations were significantly correlated with age, BMI, glucose, PRL, SHBG, and testosterone. Only the correlations with testosterone and PRL were BMI-independent. The effect of PCOS on PTH concentrations remained significant after adjustment for BMI, but not after adjustment for testosterone concentration. Increased body weight also had a significant negative effect on 25-OH- and 1,25-(OH)2-vitamin D concentrations, but no association with the syndrome was observed.

Conclusions: The results of the present study are in agreement with previous data supporting an association of increased PTH and decreased vitamin D metabolite concentrations with obesity. Moreover, the present findings indicate, for the first time, that PTH probably is also linked to PCOS-associated hyperandrogenism.
The Detection of UV‐induced Membrane Damages by a Combination of Two Biosensor Techniques
Authors: Christ Katrin , Rüttinger Hans‐Hermann , Höpfner Matthias , Rothe Ulrich , Bendas Gerd
Published: July 2005

Ketoprofen is an important anti‐inflammatory drug, but its dermal application is limited because of the photosensitizing properties causing phototoxic reactions of the skin when exposed to UV light. We have recently investigated the peroxide formation of ketoprofen in solutions of linoleic acid during UV irradiation. To continue these studies and focus on UV‐induced changes in membrane integrity and barrier function we established an in vitro model using two biosensor techniques simultaneously. Support‐fixed bilayers were irradiated with different doses of UV‐B up to damaging intensities with or without ketoprofen. Cyclic voltammetry was carried out to detect alterations in membrane permeability; quartz crystal microbalance (QCM) measurements were helpful in analyzing whether a permeability increase was caused by depletion of membrane components. In absence of ketoprofen, increasing UV‐B doses induce membrane permeabilities of both unsaturated and saturated bilayers. QCM measurements could not reveal a significant loss of membrane components as a reason for the permeability. In contrast, 0.3 mM ketoprofen induced a dose‐dependent increase in membrane permeability. QCM results indicated a mass loss. Although this model does not explain all molecular mechanisms of membrane damage by ketoprofen, the combined application of both QCM and CV is a novel and powerful tool to investigate functional mechanisms of UV‐induced membrane damages.
Validation and Application of a Fish-Based Index of Biotic Integrity for Small Central Minnesota Lakes
Authors: Drake Melissa T. , Valley Ray D.
Published: July 2005

We evaluated the performance of an index of biotic integrity (IBI) based on 16 fish population metrics of three types: species richness, community assemblage, and trophic composition. Two sets of central Minnesota lakes independent from the original set of lakes used to develop the IBI model were used to validate it. One set of lakes (n = 15) had physical features similar to those used to develop the IBI, while the other set (n = 22) averaged 9 m shallower with 28% more littoral area. We used general linear models to test whether the relationships between IBI or individual metric score and indicators of lake quality (trophic state, floristic quality, or surrounding land use) were the same or differed for the original IBI data set and each new data set. Responses were similar among all data sets, lake IBI scores and individual metrics reflecting differences in land use, trophic state, and aquatic habitat. Sensitivity of individual metrics to different measures of stress varied, supporting the need for a multimetric approach when assessing the biotic integrity of lakes. Index of biotic integrity scores were most highly correlated with trophic state (rho = −0.80). Our results support the validity of the original fish-based IBI as a standardized method for quantitatively measuring the condition of fish assemblages and implied overall biotic integrity of small central Minnesota lakes. As with any model, however, continued evaluation is recommended, especially when applying this IBI to lakes with different physical, chemical, or biological characteristics.
Tiering as a Recursion Technique
Authors: Simmons Harold
Published: July 2005

I survey the syntactic technique of tiering which can be used to restrict the power of a recursion scheme. I show how various results can be obtained entirely proof theoretically without the use of a model of computation.
Mathematical Existence
Authors: Maddy Penelope
Published: July 2005

Despite some discomfort with this grandly philosophical topic, I do in fact hope to address a venerable pair of philosophical chestnuts: mathematical truth and existence. My plan is to set out three possible stands on these issues, for an exercise in compare and contrast. A word of warning, though, to philosophical purists (and perhaps of comfort to more mathematical readers): I will explore these philosophical positions with an eye to their interconnections with some concrete issues of set theoretic method.

Let me begin with a brief look at what to count as ‘philosophy’. To some extent, this is a matter of usage, and mathematicians sometimes classify as ‘philosophical’ any considerations other than outright proofs. So, for example, discussions of the propriety of particular mathematical methods would fall under this heading: should we prefer analytic or synthetic approaches in geometry? Should elliptic functions be treated in terms of explicit representations (as in Weierstrass) or geometrically (as in Riemann)? Should we allow impredicative definitions? Should we restrict ourselves to a logic without bivalence or the law of the excluded middle? Also included in this category would be the trains of thought that shaped our central concepts: should a function always be defined by a formula? Should a group be required to have an inverse for every element? Should ideal divisors be defined contextually or explicitly, treated computationally or abstractly? In addition, there are more general questions concerning mathematical values, aims and goals: Should we strive for powerful theories or low-risk theories? How much stress should be placed on the fact or promise of physical applications? How important are interconnections between the various branches of mathematics? These philosophical questions of method naturally include several peculiar to set theory: should set theorists focus their efforts on drawing consequences for areas of interest to mathematicians outside mathematical logic? Should exploration of the standard axioms of ZFC be preferred to the exploration and exploitation of new axioms? How should axioms for set theory be chosen? What would a solution to the Continuum Problem look like?
The Role of True Finiteness in the Admissible Recursively Enumerable Degrees
Authors: Greenberg Noam
Published: July 2005

When attempting to generalize recursion theory to admissible ordinals, it may seem as if all classical priority constructions can be lifted to any admissible ordinal satisfying a sufficiently strong fragment of the replacement scheme. We show, however, that this is not always the case. In fact, there are some constructions which make an essential use of the notion of finiteness which cannot be replaced by the generalized notion of α-finiteness. As examples we discuss both codings of models of arithmetic into the recursively enumerable degrees, and non-distributive lattice embeddings into these degrees. We show that if an admissible ordinal α is effectively close to ω (where this closeness can be measured by size or by cofinality) then such constructions may be performed in the α-r.e. degrees, but otherwise they fail. The results of these constructions can be expressed in the first-order language of partially ordered sets, and so these results also show that there are natural elementary differences between the structures of α-r.e. degrees for various classes of admissible ordinals α. Together with coding work which shows that for some α, the theory of the α-r.e. degrees is complicated, we get that for every admissible ordinal α, the α-r.e. degrees and the classical r.e. degrees are not elementarily equivalent.
Tree structures associated to a family of functions
Authors: Argyros Spiros A. , Dodos Pandelis , Kanellopoulos Vassilis
Published: July 2005

The research presented in this paper was motivated by our aim to study a problem due to J. Bourgain [3]. The problem in question concerns the uniform boundedness of the classical separation rank of the elements of a separable compact set of the first Baire class. In the sequel we shall refer to these sets (separable or non-separable) as Rosenthal compacta and we shall denote by ∝(f) the separation rank of a real-valued functionfinB1(X), withXa Polish space. Notice that in [3], Bourgain has provided a positive answer to this problem in the case ofKsatisfyingwithXa compact metric space. The key ingredient in Bourgain's approach is that whenever a sequence of continuous functions pointwise converges to a functionf, then the possible discontinuities of the limit function reflect a local ℓ1-structure to the sequence (fn)n. More precisely the complexity of this ℓ1-structure increases as the complexity of the discontinuities offdoes. This fruitful idea was extensively studied by several authors (c.f. [5], [7], [8]) and for an exposition of the related results we refer to [1]. It is worth mentioning that A.S. Kechris and A. Louveau have invented the rank rND(f) which permits the link between thec0-structure of a sequence (fn)nof uniformly bounded continuous functions and the discontinuities of its pointwise limit. Rosenthal'sc0-theorem [11] and thec0-index theorem [2] are consequences of this interaction.

Passing to the case where either (fn)nare not continuous orXis a non-compact Polish space, this nice interaction is completely lost.
Bounding and nonbounding minimal pairs in the enumeration degrees
Authors: Cooper S. Barry , Li Angsheng , Sorbi Andrea , Yang Yue
Published: July 2005

We show that every nonzero Δ20, e-degree bounds a minimal pair. On the other hand, there exist Σ20, e-degrees which bound no minimal pair.
A logic for metric and topology
Authors: Wolter Frank , Zakharyaschev Michael
Published: July 2005

We propose a logic for reasoning about metric spaces with the induced topologies. It combines the ‘qualitative’ interior and closure operators with ‘quantitative’ operators ‘somewhere in the sphere of radiusr’ including or excluding the boundary. We supply the logic with both the intended metric space semantics and a natural relational semantics, and show that the latter (i) provides finite partial representations of (in general) infinite metric models and (ii) reduces the standard ‘ε-definitions’ of closure and interior to simple constraints on relations. These features of the relational semantics suggest a finite axiomatisation of the logic and provide means to prove its EXPTIME-completeness (even if the rational numerical parameters are coded in binary). An extension with metric variables satisfying linear rational (in)equalities is proved to be decidable as well. Our logic can be regarded as a ‘well-behaved’ common denominator of logical systems constructed in temporal, spatial, and similarity-based quantitative and qualitative representation and reasoning. Interpreted on the real line (with its Euclidean metric), it is a natural fragment of decidable temporal logics for specification and verification of real-time systems. On the real plane, it is closely related to quantitative and qualitative formalisms for spatial representation and reasoning, but this time the logic becomes undecidable.
Preserving preservation
Authors: Kellner Jakob , Shelah Saharon
Published: July 2005

We prove that the property “P doesn't make the old reals Lebesgue null” is preserved under countable support iterations of proper forcings, under the additional assumption that the forcings are nep (a generalization of Suslin proper) in an absolute way. We also give some results for general Suslin ccc ideals.
The axiom of elementary sets on the edge of Peircean expressibility
Authors: Formisano Andrea , Omodeo Eugenio G. , Policriti Alberto
Published: July 2005

Being able to state the principles which lie deepest in the foundations of mathematics by sentences in three variables is crucially important for a satisfactory equational rendering of set theories along the lines proposed by Alfred Tarski and Steven Givant in their monograph of 1987.

The main achievement of this paper is the proof that the ‘kernel’ set theory whose postulates are extensionality. (E), and single-element adjunction and removal. (W) and (L), cannot be axiomatized by means of three-variable sentences. This highlights a sharp edge to be crossed in order to attain an ‘algebraization’ of Set Theory. Indeed, one easily shows that the theory which results from the said kernel by addition of the null set axiom, (N), is in its entirety expressible in three variables.
PNA Encoding (PNA=peptide nucleic acid): From Solution‐Based Libraries to Organized Microarrays
Authors: Harris Jennifer L. , Winssinger Nicolas
Published: July 2005

Microarray‐based technologies have attracted attention in chemical biology by virtue of their miniaturized format, which is well suited to probe ligand–protein interactions or investigate enzymatic activity in complex biological mixtures. A number of research groups have reported the preparation of surfaces on microarrays with specific functional groups to chemoselectively attach small molecules from libraries. We have developed an alternative method whereby libraries are encoded with peptide nucleic acid (PNA), such that libraries which exist as mixtures in solution self‐assemble into an organized microarray through hybridization to produce readily available DNA arrays. This allows libraries synthesized by split and mix methods to be decoded in a single step. An asset of this method compared to direct spotting is that libraries can be used in solution for bioassays prior to self‐assembly into the microarray format.
2‐Bromophospholide Ions: Synthesis and Theoretical Study
Authors: Deschamps Eliane , Mathey François
Published: July 2005

DFT calculations at the B3 LYP/6–311++G(3df,2p) level indicate that the 2‐bromophospholide ion could be stable toward self‐arylation as a result of the lowered nucleophilicity of the in‐plane phosphorus lone pair (the corresponding σP orbital is lowered by 0.7 eV compared with the corresponding orbital of the parent phospholide ion, and the negative charge at P is reduced from −0.435 to −0.369 e). Accordingly, the synthesis of 2‐bromo‐3,4‐dimethylphospholide was successfully carried out by quantitative base‐induced dealkylation of 2‐bromo‐1‐(2‐ethoxycarbonylethyl)‐3,4‐dimethylphosphole. This ion reacts with FeCl2 to give the corresponding 2,2′‐dibromo‐3,3′,4,4′‐tetramethyl‐1,1′‐diphosphaferrocene as a poorly stable mixture of meso‐ and rac‐diastereomers in 18 % yield.
Connexin45 mediates gap junctional coupling of bistratified ganglion cells in the mouse retina
Authors: Schubert Timm , Maxeiner Stephan , Krüger Olaf , Willecke Klaus , Weiler Reto
Published: July 2005

Direction selectivity, a key feature of visual perception, originates in the retina and is transmitted by bistratified ganglion cells that, in the rabbit retina, exhibit a particular coupling pattern. We intracellularly labeled ganglion cells in different transgenic mouse lines, allowing a morphological classification of bistratified ganglion cells, an analysis of their coupling pattern, and the molecular identification of the connexins responsible for the coupling. Based on dendritic characteristics including co‐fasciculation with the dendrites of cholinergic starburst amacrine cells, we were able to distinguish three types of bistratified ganglion cells. Two of these co‐fasciculate with starburst amacrine cells and exhibit a specific homologous coupling pattern. Connexin45 (Cx45) appears to be the major component of the gap junctional channels because tracer coupling is absent in Cx45‐deficient animals whereas it persists in Cx36‐deficient animals. It is speculated that the transjunctional voltage dependence of Cx45 channels could support the transmission of direction selectivity. J. Comp. Neurol. 490:29–39, 2005. © 2005 Wiley‐Liss, Inc.
Synapse composition and organization following chronic activity blockade in cultured hippocampal neurons
Authors: Harms Kimberly J. , Craig Ann Marie
Published: July 2005

Activity plays multiple roles in the expression of synaptic plasticity, and has been shown to regulate the localization of both neurotransmitter receptors and downstream signaling machinery. However, the role of activity in central synapse formation and organization is incompletely understood. Some studies indicate that synapse formation can occur in the absence of synaptic activity, while others indicate that activity is required for synapse maintenance and receptor recruitment. In addition, the effects of long‐term blockade of transmission generally, rather than blockade of specific receptors, on postsynaptic protein complement has been poorly characterized. In order to address the role of activity in synapse formation and postsynaptic specialization, we used tetanus toxin to chronically cleave VAMP2 and inhibit SNARE‐mediated neurotransmitter release in cultured hippocampal neurons. Although these neurons are deficient in synaptic release, they are of normal size and morphology. In addition, both excitatory and inhibitory synapses form along their processes with normal density. These synapses have a remarkably similar cellular and molecular organization compared to controls, and are capable of recruiting postsynaptic scaffolding proteins, GABA, and glutamate receptors. Subcellular enrichment of synaptic proteins into specialized domains also appears intact. These data indicate that global activity inhibition is insufficient to disrupt central synapse formation or organization. J. Comp. Neurol. 490:72–84, 2005. © 2005 Wiley‐Liss, Inc.
Developmental modifications of olivocerebellar topography: The granuloprival cerebellum reveals multiple routes from the inferior olive
Authors: Fournier Betty , Lohof Ann M. , Bower Adrian J. , Mariani Jean , Sherrard Rachel M.
Published: July 2005

Correct function of neural circuits depends on highly organized neuronal connections, refined from less precise projections through synaptic elimination, collateral regression, or neuronal death. We examined regressive phenomena that define olivocerebellar topography during maturation from Purkinje cell polyinnervation to monoinnervation. We used bilateral retrograde tracing to determine the source of olivocerebellar afferents to posterior vermis lobules VII–VIII in a model of retained immature Purkinje cell polyinnervation, the granuloprival cerebellum. In controls, labelled neurons were found only in the contralateral inferior olive (ION) clustered in a small ventromedial locus that is congruent with known olivocerebellar topography. In granuloprival animals, olivary labelling appeared more dispersed and was present in homologous ipsilateral regions. Double‐labelled neurons were never seen. Retrograde tracing following unilateral olivocerebellar transection in adult granuloprival rats revealed: 1) the origin of the normal (remaining) path projecting through the contralateral inferior peduncle was more localized than in irradiated nonpedunculotomized rats, 2) a small double‐crossed path, and 3) a projection that ascends the peduncle ipsilateral to the ION of origin, part of which crosses the midline within the cerebellum. Electrophysiological and immunohistochemical assessment in the neonatal cerebellum revealed that transcommissural paths are not present during development but sprout within the irradiated cerebellum. Therefore, the olivocerebellar projection in the granuloprival rat, as a model of the immature path, shows parasagittal organization similar to that of controls in its normally crossed path but possesses additional abnormal projections. Thus, maturation of olivocerebellar topography involves removal of whole developmental paths to define laterality plus synapse elimination within largely predefined parasagittal zones. J. Comp. Neurol. 490:85–97, 2005. © 2005 Wiley‐Liss, Inc.
Novel insect orcokinins: Characterization and neuronal distribution in the brains of selected dicondylian insects
Authors: Hofer Sabine , Dircksen Heinrich , Tollbäck Petter , Homberg Uwe
Published: July 2005

Orcokinins are a family of myotropic neuropeptides identified in various decapod crustaceans and recently in a cockroach. Their presence in the crustacean nervous system and hemolymph suggests that they act as hormones and as locally acting neuromodulators. To provide further evidence for the existence of orcokinins in insects, we identified a novel orcokinin‐related peptide in the locust Schistocerca gregaria and used an antiserum against Asn13‐orcokinin for immunostaining in the brains of selected dicondylian insects, including a silverfish, three polyneopteran species (a cockroach and two locusts), and three endopterygote species (a moth, a bee, and a fly). As analyzed by MALDI‐TOF spectrometry and nanoelectrospray Q‐TOF, the locust orcokinin is a novel tetradecapeptide with striking sequence similarity to crustacean orcokinins. Orcokinin immunostaining was widespread and occurred in similar patterns in the brain of the silverfish and the polyneopteran species. Prominent immunostaining was detected in the optic lobe, especially in the medulla and in the accessory medulla, in local interneurons of the antennal lobe, and in extrinsic and intrinsic mushroom‐body neurons. All parts of the central complex and many other areas of the brains were densely stained. In the silverfish, the cockroach, and the locusts, processes in the corpora cardiaca showed orcokinin immunoreactivity, suggesting that orcokinins also serve a hormonal role. In contrast to the case in polyneopteran species, immunostaining was completely lacking in the brains of the honeybee, fruitfly, and sphinx moth. This indicates that orcokinins either are modified considerably or may be completely absent in the brains of endopterygote insects. J. Comp. Neurol. 490:57–71, 2005. © 2005 Wiley‐Liss, Inc.
Dietary fat, fatty acid composition and risk of cancer
Authors: Gerber Mariette , Thiébaut Anne , Astorg Pierre , Clavel‐Chapelon Françoise , Combe Nicole
Published: July 2005

The relationship between dietary fat, fatty acids and cancers has been debated for a long time. The difficulty to disentangle the effects of specific nutrients, in a particular food or from a similar food pattern, from one another partly explains this. In addition, the complex interaction between nutrients at the different stages of carcinogenesis has contributed to the uncertainty of cause‐and‐effect. Finally, methodological considerations have also played a role in this debate. However, the knowledge and understanding of the role of dietary fat in cancer has progressed. Factors related to a high energy intake, such as obesity, are probable if not convincing risk factors for several cancers. Therefore, epidemiological findings tend to suggest that dietary fatty acids increase the risk of cancer. This is especially so for the least oxidisable, saturated and monounsaturated fatty acids. Polyunsaturatedn‐6 fatty acids and especially linoleic acid, which reproducibly enhances tumour incidence and growth in animal models, do not appear to have the same effects in humans. Interaction with other nutrients, such asn‐3 fatty acids and antioxidants, may explain this apparent contradiction. The major question yet unanswered and deserving more studies is the relation betweenn‐3 fatty acids (especially α‐linolenic acid) and prostate cancer. Progress in this area requires more complete food composition data and other experimental models of carcinogenesis.
“In‐gel patch electrophoresis:” A new method for environmental DNA purification
Authors: Roh Changhyun , Villatte Francois , Kim Byung‐Gee , Schmid Rolf D.
Published: July 2005

Most of the microorganism species are largely untapped and could represent an interesting reservoir of genes useful for biotechnological applications. Unfortunately, a major difficulty associated with the methods used to isolate environmental DNA is related to the contamination of the extracted material with humic substances. These polyphenolic compounds inhibit the DNA processing reactions and severely impede cloning procedures. In this work, we describe a rapid, simple, and efficient method for the purification of genomic DNA from environmental samples: we added a chromatography step directly embedded into an agarose gel electrophoresis. This strategy enabled the DNA extraction from various environmental samples and it appeared that the purity grade was compatible with digestion by restriction enzymes and polymerase chain reaction (PCR) amplifications.
Analyses of phenolic compounds by microemulsion electrokinetic chromatography
Authors: Huang Hsi‐Ya , Lien Wei‐Chih
Published: July 2005

In this study, a microemulsion electrokinetic chromatography (MEEKC) method was developed to analyze and detect 13 phenolic compounds (syringic acid, p‐cumaric acid, vanillic acid, caffeic acid, gallic acid, 3,4‐dihydroxybenzoic acid, 4‐hydroxybenzoic acid, (+)‐catechin, (−)‐epigallocatechin, (−)‐epicatechin gallate, (−)‐epigallocatechin gallate, (−)‐epicatechin, and (−)‐gallocatechin), which are present in many plant‐derived foods. The effects of cosurfactant, organic modifier, and oil were examined in order to optimize the separation of these phenolic compounds. The amounts of cosurfactant (cyclohexanol) and organic modifier (acetonitrile) were determined as the major influence on the separation selectivity, while the type of oil partially affected the separation resolution of the phenolic compounds. A highly efficient MEEKC separation method was achieved within 14 min by using a microemulsion solution of pH 2.0 containing 2.89% w/v SDS, 1.36% w/v heptane, 7.66% w/v cyclohexanol, and 2% w/v ACN. Furthermore, the present work could demonstrate that the nature of the oil phase has a significant influence on the separation selectivity of phenolic compounds.
A family of single‐isomer positively charged cyclodextrins as chiral selectors for capillary electrophoresis: Mono‐6A‐butylammonium‐6A‐deoxy‐β‐cyclodextrin tosylate
Authors: Tang Weihua , Muderawan I Wayan , Ong Teng Teng , Ng Siu‐Choon
Published: July 2005

A novel single‐isomer positively charged β‐cyclodextrin (β‐CD), mono‐6A‐butylammonium‐6A‐deoxy‐β‐cyclodextrin tosylate (BuAM‐β‐CD), has been synthesized, characterized, and used for the enantioseparations of α‐hydroxy acids, carboxylic acids, and ampholytic analytes by capillary electrophoresis in acidic aqueous background electrolytes. The effective mobilities of all studied analytes decreased with increasing concentration of CD. Satisfactory resolutions were obtained for α‐hydroxy acids over a wide range of chiral selector concentration. The optimum CD concentration was lower than 5 mM for the carboxylic acids, while higher than 20 mM for α‐hydroxy acids. Inclusion complexation in combination with ion pair interaction seemed to account for the chiral discrimination process. The hydrogen bonding may provide secondary contribution for the chiral resolution of α‐hydroxy acids. In addition, BuAM‐β‐CD was further proved to be an effective chiral selector for anionic analytes by the baseline enantioseparation of a six‐acid mixture within 20 min.
Poly(methylmethacrylate) and Topas capillary electrophoresis microchip performance with electrochemical detection
Authors: Castaño‐Álvarez Mario , Fernández‐Abedul María T. , Costa‐García Agustín
Published: July 2005

A capillary electrophoresis (CE) microchip made of a new and promising polymeric material: Topas (thermoplastic olefin polymer of amorphous structure), a cyclic olefin copolymer with high chemical resistance, has been tested for the first time with analytical purposes, employing an electrochemical detection. A simple end‐channel platinum amperometric detector has been designed, checked, and optimized in a poly‐(methylmethacrylate) (PMMA) CE microchip. The end‐channel design is based on a platinum wire manually aligned at the exit of the separation channel. This is a simple and durable detection in which the working electrode is not pretreated. H2O2 was employed as model analyte to study the performance of the PMMA microchip and the detector. Factors influencing migration and detection processes were examined and optimized. Separation of H2O2 and L‐ascorbic acid (AsA) was developed in order to evaluate the efficiency of microchips using different buffer systems. This detection has been checked for the first time with a microchip made of Topas, obtaining a good linear relationship for mixtures of H2O2 and AsA in different buffers.
Carotenoids in representatives of the Protousnea (Parmeliaceae), endemic genus from South America
Authors: Czeczuga B. , Czeczuga‐Semeniuk E. , Calvelo S. , Liberatore S.
Published: July 2005

Column, thin‐layer and reverse‐phase high‐performance liquid chromatography revealed the presence of the following carotenoids in the thalli of 7 lichen species representatives of the Protousnea (Parmeliaceae) endemic genus from South America: α‐carotene, β‐carotene, retrodehydro‐β‐carotene, α‐cryptoxanthin, β‐cryptoxanthin, lycopene‐5,6‐epoxide, lutein, 3′‐epilutein, zeaxanthin, antheraxanthin, cryptoflavin, loroxanthin, capsochrome, neoxanthin, violaxanthin, 3‐hydroxyechinenone, adonixanthin, canthaxanthin, astaxanthin, rhodoxanthin, citranaxanthin and torularhodin methyl ester.

The total content of carotenoids ranged from 32.45 (Protousnea dusenii) to 48.21 μg g–1 dry weight (Protousnea teretiuscula). (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A new species of Porphyra (Rhodophyta, Bangiales) from the Malvan coast of Maharashtra (India)
Authors: Anilkumar C. , Rao P. S. N.
Published: July 2005

A new species of Porphyra C.A.Agardh, Porphyra malvanensis Anilkumar & P.S.N.Rao, sp. nova, has been reported from the Malvan coast of Maharashtra, India. The present species is clearly distinguished from the other Indian species reported so far, by its small size, the development pattern, arrangement and the number of carpospores and spermatia. The morphology of the present species is studied in detail together with the development of carpospores and spermatia. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)