bluuebunny/crossref_metadata_2025 huggingface dataset:
Protein Flexibility and Ligand Rigidity: A Thermodynamic and Kinetic Study of ITAM‐Based Ligand Binding to Syk Tandem SH2
Authors: de Mol Nico J. , Catalina M. Isabel , Dekker Frank J. , Fischer Marcel J. E. , Heck Albert J. R. , Liskamp Rob M. J.
Published: October 2005

The Syk tandem Src homology 2 domain (Syk tSH2) constitutes a flexible protein module involved in the regulation of Syk kinase activity. The Syk tSH2 domain is assumed to function by adapting the distance between its two SH2 domains upon bivalent binding to diphosphotyrosine ligands. A thermodynamic and kinetic analysis of ligand binding was performed by using surface plasmon resonance (SPR). Furthermore, the effect of binding on the Syk tSH2 structural dynamics was probed by hydrogen/deuterium exchange and electrospray mass spectrometry (ESI‐MS). Two ligands were studied:1, a flexible peptide derived from the tSH2 recognition ITAM sequence at the γ chain of the FcεRI‐receptor, and2, a ligand in which the amino acids between the two SH2 binding motifs in ligand1have been replaced by a rigid linker of comparable length. Both ligands display comparable affinity for Syk tSH2 at 25 °C, yet a major difference in thermodynamics is observed. Upon binding of the rigid ligand,2, the expected entropy advantage is not realized. On the contrary,2binds with a considerably higher entropy price of ∼9 kcal mol−1, which is attributed to a further decrease in protein flexibility upon binding to this rigid ligand. The significant reduction in deuterium incorporation in the Syk tSH2 protein upon binding of either1or2, as monitored by ESI‐MS, indicates a major reduction in protein dynamics upon binding. The results are consistent with a two‐step binding model: after an initial binding step, a rapid structural change of the protein occurs, followed by a second binding step. Such a bivalent binding model allows high affinity and fast dissociation kinetics, which are very important in transient signal‐transduction processes.
Design of a Hairpin Polyamide, ZT65B, for Targeting the Inverted CCAAT Box (ICB) Site in the Multidrug Resistant (MDR1) Gene
Authors: Buchmueller Karen L. , Taherbhai Zarmeen , Howard Cameron M. , Bailey Suzanna L. , Nguyen Binh , O’Hare Caroline , Hochhauser Daniel , Hartley John A. , Wilson W. David , Lee Moses
Published: October 2005

A novel hairpin polyamide, ZT65B, containing a 3‐methylpicolinate moiety was designed to target the inverted CCAAT box (ICB) of the human multidrug resistance 1 gene (MDR1) promoter. Binding of nuclear factor‐Y (NF‐Y) to the ICB site upregulates MDR1 gene expression and is, therefore, a good target for anticancer therapeutic agents. However, it is important to distinguish amongst different promoter ICB sites so that only specific genes will be affected. All ICB sites have the same sequence but they differ in the sequence of the flanking base pairs, which can be exploited in the design of sequence‐specific polyamides. To test this hypothesis, ten ICB‐containing DNA hairpins were designed with different flanking base pairs; the sequences ICBa and ICBb were similar to the 3′‐ICB site of MDR1 (TGGCT). Thermal‐denaturation studies showed that ZT65B effectively targeted ICBa and ICBb (ΔTM=6.5 and 7.0 °C) in preference to the other DNA hairpins (<3.5 °C), with the exception of ICBc (5.0 °C). DNase I‐footprinting assays were carried out with the topoisomerase IIα‐promoter sequence, which contains five ICB sites; of these, ICB1 and ICB5 are similar to the ICB site of MDR1. ZT65B was found to selectively bind ICB1 and ICB5; footprints were not observed with ICB2, ICB3, or ICB4. A strong, positive induced ligand band at 325 nm in CD studies confirmed that ZT65B binds in the DNA minor groove. The selectivity of ZT65B binding to hairpins that contained the MDR1 ICB site compared to one that did not (ICBd) was confirmed by surface‐plasmon studies, and equilibrium constants of 5×106–1×107 and 4.6×105 M−1 were obtained with ICB1, ICB5,and ICB2 respectively. ZT65B and the previously published JH37 (J. A. Henry, et al. Biochemistry 2004, 43, 12 249–12 257) serve as prototypes for the design of novel polyamides. These can be used to specifically target the subset of ubiquitous gene elements known as ICBs, and thereby affect the expression of one or a few proteins.
Development of a Novel Chemical Probe for the Selective Enrichment of Phosphorylated Serine‐ and Threonine‐Containing Peptides
Authors: van der Veken Pieter , Dirksen Eef H. C. , Ruijter Eelco , Elgersma Ronald C. , Heck Albert J. R. , Rijkers Dirk T. S. , Slijper Monique , Liskamp Rob M. J.
Published: October 2005

Gaining insight into phosphoproteomes is of the utmost importance for understanding regulation processes such as signal transduction and cellular differentiation. While the identification of phosphotyrosine‐containing amino acid sequences in peptides and proteins is now becoming possible, mainly because of the availability of high‐affinity antibodies, no general and robust methodology allowing the selective enrichment and analysis of serine‐ and threonine‐phosphorylated proteins and peptides is presently available. The method presented here involves chemical modification of phosphorylated serine or threonine residues and their subsequent derivatization with the aid of a multifunctional probe molecule. The designed probe contains four parts: a reactive group that is used to bind specifically to the modified phosphopeptide, an optional part in which heavy isotopes can be incorporated, an acid‐labile linker, and an affinity tag for the selective enrichment of modified phosphopeptides from complex mixtures. The acid‐cleavable linker allows full recovery from the affinity‐purified material and removal of the affinity tag prior to MS analysis. The preparation of a representative probe molecule containing a biotin affinity tag and its applicability in phosphoproteome analysis is shown in a number of well‐defined model systems of increasing degrees of complexity. Amounts of phosphopeptide as low as 1 nmol can be modified and enriched from a mixture of peptides. During the development of the β‐elimination/nucleophilic addition protocol, special attention was paid to the different experimental parameters that might affect the chemical‐modification steps carried out on phosphorylated residues.
Solid Film versus Solution‐Phase Charge‐Recombination Dynamics of exTTF–Bridge–C60 Dyads
Authors: Handa Samantha , Giacalone Francesco , Haque Saif A. , Palomares Emilio , Martín Nazario , Durrant James R.
Published: October 2005

The charge‐recombination dynamics of two exTTF–C60 dyads (exTTF=9,10‐bis(1,3‐dithiol‐2‐ylidene)‐9,10‐dihydroanthracene), observed after photoinduced charge separation, are compared in solution and in the solid state. The dyads differ only in the degree of conjugation of the bridge between the donor (exTTF) and the acceptor (C60) moieties. In solution, photoexcitation of the nonconjugated dyad C60–BN–exTTF (1) (BN=1,1′‐binaphthyl) shows slower charge‐recombination dynamics compared with the conjugated dyad C60–TVB–exTTF (2) (TVB=bisthienylvinylenebenzene) (lifetimes of 24 and 0.6 μs, respectively), consistent with the expected stronger electronic coupling in the conjugated dyad. However, in solid films, the dynamics are remarkably different, with dyad 2 showing slower recombination dynamics than 1. For dyad 1, recombination dynamics for the solid films are observed to be tenfold faster than in solution, with this acceleration attributed to enhanced electronic coupling between the geminate radical pair in the solid film. In contrast, for dyad 2, the recombination dynamics in the solid film exhibit a lifetime of 7 μs, tenfold slower than that observed for this dyad in solution. These slow recombination dynamics are assigned to the dissociation of the initially formed geminate radical pair to free carriers. Subsequent trapping of the free carriers at film defects results in the observed slow recombination dynamics. It is thus apparent that consideration of solution‐phase recombination data is of only limited value in predicting the solid‐film behaviour. These results are discussed with reference to the development of organic solar cells based upon molecular donor–acceptor structures.
Electron‐Rich Tetrathiafulvalene–Triarylamine Conjugates: Synthesis and Redox Properties
Authors: Li Hongchao , Lambert Christoph
Published: October 2005

By combining tetrathiafulvalenes (TTFs) and triarylamines, four TTF–triarylamine conjugates bridged by an annulated pyrrole ring were designed and synthesized by an N‐arylation reaction. Electrochemical and photophysical investigations suggest that these novel conjugates possess very strong electron‐donating ability with very high HOMO energy levels of around −4.70 eV; the HOMOs are mainly located on the TTF moiety. We observed significant electronic coupling between the TTF moieties and the triarylamine groups. However, no evidence for such electronic communication between end‐capping TTF units (conjugates 5 and 7) or between two terminal triarylamine groups (conjugate 9) could be found. Differential scanning calorimetry (DSC) measurements together with PM3‐optimized geometries suggest that conjugates 5 and 7, which adopt three‐dimensional propeller‐shaped structures, may easily pack and crystallize in the solid state because of the large rigid planar blades consisting of TTF and one of the phenyl rings of the triarylamine moiety. However, conjugate 9, with two bulky end‐capping triarylamine groups, forms an amorphous material with a glass transition at 74.5 °C.
The Hit‐to‐Lead Process at Schering AG: Strategic Aspects
Authors: Steinmeyer Andreas
Published: October 2005

Modern organizations conducting drug‐discovery programs frequently apply high‐throughput screening to generate novel hit structures for the indications of interest. Systematic hit‐to‐lead processes have been established at most pharmaceutical companies to ensure a smooth conversion of hits into high‐quality lead structures. At Schering AG, a hit‐to‐lead process with distinct selection criteria was introduced in 1999 to identify the best leads possible. The thorough evaluation of hits and lead candidates allows risk assessments, which facilitate the assignment of valuable resources to those lead‐discovery projects with the most chances of success. A dedicated hit‐to‐lead team has been formed to oversee the process and to provide guidance to the respective project teams.
Unitary hypothesis for multiple triggers of the pain and strain of migraine
Authors: Burstein Rami , Jakubowski Moshe
Published: October 2005

Migraine headache is triggered by and associated with a variety of hormonal, emotional, nutritional, and physiological changes. The perception of migraine headache is formed when nociceptive signals originating in the meninges are conveyed to the somatosensory cortex through the trigeminal ganglion, medullary dorsal horn, and thalamus. Is there a common descending pathway accounting for the activation of meningeal nociceptors by different migraine triggers? We propose that different migraine triggers activate a wide variety of brain areas that impinge on parasympathetic neurons innervating the meninges. According to this hypothesis, migraine triggers such as perfume, stress, or awakening activate multiple hypothalamic, limbic, and cortical areas, all of which contain neurons that project to the preganglionic parasympathetic neurons in the superior salivatory nucleus (SSN). The SSN, in turn, activates postganglionic parasympathetic neurons in the sphenopalatine ganglion, resulting in vasodilation and local release of inflammatory molecules that activate meningeal nociceptors. Are there ascending pathways through which the trigeminovascular system can induce the wide variety of migraine symptoms? We propose that trigeminovascular projections from the medullary dorsal horn to selective areas in the midbrain, hypothalamus, amygdala, and basal forebrain are functionally positioned to produce migraine symptoms such as irritability, loss of appetite, fatigue, depression, or the quest for solitude. Bidirectional trafficking by which the trigeminovascular system can activate the same brain areas that have triggered its own activity in the first place provides an attractive network of perpetual feedback that drives a migraine attack for many hours and even days. J. Comp. Neurol. 493:9–14, 2005. © 2005 Wiley‐Liss, Inc.
Relevance of an evidence‐based ejaculation time cutoff point for neurobiological research of premature ejaculation
Authors: Waldinger Marcel D.
Published: October 2005

The Diagnostic and Statistical Manual (DSM)‐IV definition of premature ejaculation is not based on evidence‐based studies. In particular, the absence of a well‐defined quantitative measure of the intravaginal ejaculation latency time (IELT) makes the DSM definition inadequate. Therefore, the DSM‐IV definition should be replaced by a medical definition that incorporates both quantitative as qualitative parameters of premature ejaculation. An evidence‐based medical definition should include a cutoff point of the IELT at the 0.5 and 2.5 percentiles of the IELT distribution in the general male population. Such a definition has recently been proposed on the basis of a stopwatch study of the IELT in 491 men from five different countries. Similarly, a cutoff point of ejaculation frequency in laboratory rats enhances the probability to distinguish genuine rapid‐ejaculator rats. Only by the strict application of these cutoff points is the probability enhanced that human and animal neurobiological research can prove whether these sexual endophenotypes differ in brain activation, have particular genetic genotypes (polymorphisms), are strictly under genetic control, or are dependent on environmental conditions and/or genotypic/environmental interactions. J. Comp. Neurol. 493:46–50, 2005. © 2005 Wiley‐Liss, Inc.
Role of Barrington's nucleus in micturition
Authors: Sasaki Mitsuyoshi
Published: October 2005

Barrington's nucleus is a central component of the micturition circuit. This nucleus projects axons to the sacral parasympathetic nucleus, where preganglionic neurons innervating the urinary bladder are located. To clarify the functional role of this nucleus, the firing properties of Barrington's neurons that project axons to the spinal cord were examined. Based on these studies, a model begins to emerge that places Barrington's nucleus in the micturition pathway that is involved in increasing bladder pressure rapidly and strongly, while also maintaining high bladder pressure. In addition, Barrington's neurons are suggested to have another role, that is, increasing the probability of micturition contraction by activating a spinal excitatory pathway or disinhibiting a spinal inhibitory mechanism. In contrast to the excitatory role of Barrington's nucleus, this nucleus does not seem to trigger bladder relaxation. J. Comp. Neurol. 493:21–26, 2005. © 2005 Wiley‐Liss, Inc.
Generalized arousal of mammalian central nervous system
Authors: Pfaff Donald , Westberg Lars , Kow Lee‐Ming
Published: October 2005

A fundamental capacity of the mammalian CNS is becoming amenable to study with the techniques of functional genomics. Emphasized in this review are ascending connections from the medullary reticular formation and descending connections from the paraventricular nucleus of the hypothalamus. In particular, sex hormone effects on neurons allow us to relate generalized arousal to a specific form of arousal which is required for reproductive behaviors. J. Comp. Neurol. 493:86–91, 2005. © 2005 Wiley‐Liss, Inc.
Neural mechanisms of freezing and passive aversive behaviors
Authors: Jhou Thomas
Published: October 2005

Cues that predict aversive outcomes often produce marked inhibitions of behavior known as freezing, but it is unknown exactly what neural pathways cause this inhibition. The amygdala and bed nucleus of the stria terminalis, along with their projections to the periaqueductal gray, are strongly implicated in freezing, but it is not known how these structures inhibit motor output. The median raphe nucleus (MRN), which contains a major population of serotonin neurons, has also been implicated in freezing, but the serotonin neurons themselves do not seem to be involved, leaving it uncertain which neurons in this area promote freezing. Our recent work suggests that GABAergic neurons just lateral to the MRN, but not within the MRN, regulate freezing via projections to midbrain dopamine neurons. Because freezing pathways may control a variety of other passive aversive behaviors, their elucidation may help understand the mechanisms of addictions and compulsions, which involve a failure of aversive outcomes to inhibit behavior. J. Comp. Neurol. 493:111–114, 2005. © 2005 Wiley‐Liss, Inc.
Free will versus survival: Brain systems that underlie intrinsic constraints on behavior
Authors: Price Joseph L.
Published: October 2005

This article discusses the neuroanatomical systems involved in the related functions of fear and discernment of the consequences of one's actions, two internal constraints on free will and action. Both mechanisms are related to a system for control and modulation of visceral function stretching from the spinal cord to the ventromedial prefrontal cortex, including the ventral striatum, ventral pallidum, and mediodorsal thalamus, the amygdala, the hypothalamus, the periaqueductal gray (PAG), and the brainstem reticular formation and autonomic nuclei. Reflexes at the lower levels provide rapid visceral and somatic reactions to threatening stimuli, while the PAG and hypothalamus coordinate these to produce more concerted responses. The amygdala interacts with the cortical sensory systems in the assessment of fear‐related stimuli and modulates the reflex responses through projections to the hypothalamus and brainstem. The ventromedial prefrontal cortex, especially the “medial prefrontal network,” is connected to the amygdala, hypothalamus, and PAG, and allows cortical control over the system in relation to a wider set of emotions. This cortical region is involved both in the assessment of reward and in mood disorders and it plays a central role in the ability to discern the consequences of one's actions and make appropriate behavioral choices. It also forms an interconnected circuit with specific cortical areas in the rostral superior temporal cortex, posterior parahippocampal cortex, and retrosplenial/posterior cingulate cortex. The overall function of this circuit is unclear, but may be involved in introspective monitoring of the individual. J. Comp. Neurol. 493:132–139, 2005. © 2005 Wiley‐Liss, Inc.
Intrinsic brain activity sets the stage for expression of motivated behavior
Authors: Raichle Marcus E. , Gusnard Debra A.
Published: October 2005

Research in many species has provided increasingly detailed information on relevant, primarily subcortical brain systems supporting the expression of basic appetites and drives. While basic appetites and drives are essential for adaptation and survival in any environment, they are naturally constrained by an organism's inherent biology and modulated as circumstances dictate. The brain mechanisms which serve to constrain and modulate them, however, remain much less well understood. We suggest that the manner in which such constraint and potential modulation is achieved likely involves processes that emerge from the coordinated behavior of multiple brain systems, and functional brain imaging techniques such as PET and fMRI are beginning to help us understand aspects of such coordination. In this review we argue that, in pursuit of this understanding, we must focus not only on changes evoked in brain systems during various behaviors, but also on the ongoing and very costly intrinsic activity within these systems, for the latter may be at least as important as the evoked activity in terms of brain function in general and the constraint and modulation of basic appetites and drives in particular. Distinguishing intrinsic from evoked activity in the context of functional brain imaging experiments is challenging, however. Here we review some evolving strategies for doing so. J. Comp. Neurol. 493:167–176, 2005. © 2005 Wiley‐Liss, Inc.
Immunohistochemical localization of GAD67‐expressing neurons and processes in the rat brainstem: Subregional distribution in the nucleus tractus solitarius
Authors: Fong Angelina Y. , Stornetta Ruth L. , Foley C. Michael , Potts Jeffrey T.
Published: October 2005

The role of γ‐aminobutyric acid (GABA) in homeostatic control in the brainstem, in particular, in the nucleus tractus solitarius (NTS), is well established. However, to date, there is no detailed description of the distribution of GABAergic neurons within the NTS. The goal of the current study was to reexamine the efficacy of immunohistochemical localization of glutamic acid decarboxylase (GAD) protein, specifically the 67‐kDa isoform (GAD67), as a marker for GABAergic neurons in the medulla and to provide a detailed map of GAD67‐immunoreactive (‐ir) cells within rat NTS by using a recently developed mouse monoclonal antibody. We describe a distribution of GAD67‐ir cells in the medulla similar to that reported previously from in situ hybridization study. GAD67‐ir cells were localized in regions known to contain high GABA content, including the ventrolateral medulla, raphe nuclei, and area postrema, but were absent from all motor nuclei, although dense terminal labeling was discerned in these regions. In the NTS, GAD67‐ir was localized in all subregions. Semiquantitative analysis of the GAD67‐ir distribution in the NTS revealed greater numbers of GAD67‐ir cells medial to the solitary tract. Finally, dense GAD67 terminal labeling was found in the medial, central, intermediate, commissural, and subpostremal subregions, whereas sparse labeling was observed in the ventral subregion. Our findings support the use of immunohistochemistry for GAD67 as a marker for the localization of GABAergic cells and terminal processes in the rat brainstem. Furthermore, the reported heterogeneous distribution of GAD67‐ir in the NTS suggests differential inhibitory modulation of sensory processing. J. Comp. Neurol. 493:274–290, 2005. © 2005 Wiley‐Liss, Inc.
Expression and function of the neuronal gap junction protein connexin 36 in developing mammalian retina
Authors: Hansen Kristi A. , Torborg Christine L. , Elstrott Justin , Feller Marla B.
Published: October 2005

With the advent of transgenic mice, much has been learned about the expression and function of gap junctions. Previously, we reported that retinal ganglion cells in mice lacking the neuronal gap junction protein connexin 36 (Cx36) have nearly normal firing patterns at postnatal day 4 (P4) but many more asynchronous action potentials than wild‐type mice at P10 (Torborg et al. [2005] Nat. Neurosci. 8:72–78). With the goal of understanding the origin of this increased activity in Cx36–/– mice, we used a transgenic mouse (Deans et al. [2001] Neuron 31:477–485) to characterize the developmental expression of a Cx36 reporter in the retina. We found that Cx36 was first detected weakly at P2 and gradually increased in expression until it reached an adult pattern at P14. Although the onset of expression varied by cell type, we identified Cx36 in the glycinergic AII amacrine cell, glutamatergic cone bipolar cell, and retinal ganglion cells (RGCs). In addition, we used calcium imaging and multielectrode array recording to characterize further the firing patterns in Cx36–/– mice. Both correlated and asynchronous action potentials in P10 Cx36–/– RGCs were significantly inhibited by bath application of an ionotropic glutamate receptor antagonist, indicating that the increase in activity was synaptically mediated. Hence, both the expression patterns and the physiology suggest an increasing role for Cx36‐containing gap junctions in suppressing RGC firing between waves during postnatal retinal development. J. Comp. Neurol. 493:309–320, 2005. © 2005 Wiley‐Liss, Inc.
Frontotemporal and dopaminergic control of idea generation and creative drive
Authors: Flaherty Alice W.
Published: October 2005

This article presents a three‐factor anatomical model of human idea generation and creative drive, focusing on interactions between the temporal lobes, frontal lobes, and limbic system. Evidence is drawn from functional imaging, drug studies, and lesion analysis. Temporal lobe changes, as in hypergraphia, often increase idea generation, sometimes at the expense of quality. Frontal lobe deficits may decrease idea generation, in part because of rigid judgments about an idea's worth. These phenomena are clearest in verbal creativity, and roughly parallel the pressured communication of temporal lobe epilepsy, mania, and Wernicke's aphasia—compared to the sparse speech and cognitive inflexibility of depression, Broca's aphasia, and other frontal lobe lesions. The phenomena also shape non‐linguistic creativity, as in that of frontotemporal dementia. The appropriate balance between frontal and temporal activity is mediated by mutually inhibitory corticocortical interactions. Mesolimbic dopamine influences novelty seeking and creative drive. Dopamine agonists and antagonists have opposite effects on goal‐directed behavior and hallucinations. Creative drive is not identical to skill—the latter depends more on neocortical association areas. However, drive correlates better with successful creative output than skill does. Traditional neuroscientific models of creativity, such as the left brain – right brain hemispheric model, emphasize skills primarily, and stress art and musical skill at the expense of language and mathematics. The three‐factor model proposed here predicts findings in a broad range of normal and pathological states and can be tested in many experimental paradigms. J. Comp. Neurol. 493:147–153, 2005. © 2005 Wiley‐Liss, Inc.
Neural control of ejaculation
Authors: Coolen Lique M.
Published: October 2005

Ejaculation is the most reinforcing component of sexual behavior. However, the neural substrates mediating ejaculation and processing ejaculation‐related signals remain poorly understood. We review the current understanding of central control of ejaculation. Specifically, the recent identification of a candidate spinothalamic pathway involved in relay of ejaculation‐specific signals is discussed. In addition, the discovery of a neural population of lumbar interneurons playing an pivotal role in expression of ejaculation is reviewed. J. Comp. Neurol. 493:39–45, 2005. © 2005 Wiley‐Liss, Inc.
Development and evolution of hidden regulators: Selective breeding for an infantile phenotype
Authors: Brunelli Susan A.
Published: October 2005

Mother‐infant separation in the rat has been used as an analytical tool to reveal biosocial processes underlying infant physiology and behavior. The same strategy has guided a project in which selective breeding for an infantile behavior has provided insights into how biological systems become recruited and integrated as expressions of temperamental affective responses. Two lines of rats (High and Low USV lines) were selectively bred based on rates of USV emission to maternal separation and isolation at postnatal day (P) 10. After many generations of breeding, the High and Low lines show widespread and distinctly different profiles of physiology and behavior in the first 3 weeks of life. Insights gained from longitudinal studies suggest that selection may work by reorganizing developmental processes, not just a given trait, over the postnatal period. As animal models, the lines have the potential to provide valuable tools for understanding developmental mechanisms underlying genetic and developmental risk for depression/anxiety syndromes in children and adults. © 2005 Wiley Periodicals, Inc. Dev Psychobiol 47: 243–252, 2005.
Attachment, loss, and complicated grief
Authors: Shear Katherine , Shair Harry
Published: October 2005

Bereavement is a highly disruptive experience that is usually followed by a painful but time‐limited period of acute grief. An unfortunate minority of individuals experience prolonged and impairing complicated grief, an identifiable syndrome that differs from usual grief, major depression, and other DSM IV diagnostic entities. Underlying processes guiding symptoms are not well understood for either usual or complicated grief. We propose a provisional model of bereavement, guided by Myron Hofer's question “What exactly is lost when a loved one dies?” We integrate insights about biobehavioral regulation from Hofer's animal studies of infant separation, research on adult human attachment, and new ideas from bereavement research. In this model, death of an attachment figure produces a state of traumatic loss and symptoms of acute grief. These symptoms usually resolve following revision of the internalized representation of the deceased to incorporate the reality of the death. Failure to accomplish this integration results in the syndrome of complicated grief. © 2005 Wiley Periodicals, Inc. Dev Psychobiol 47: 253–267, 2005.
Neurobiology of infant attachment
Authors: Moriceau Stephanie , Sullivan Regina M.
Published: October 2005

A strong attachment to the caregiver is critical for survival in altricial species, including humans. While some behavioral aspects of attachment have been characterized, its neurobiology has only recently received attention. Using a mammalian imprinting model, we are assessing the neural circuitry that enables infant rats to attach quickly to a caregiver, thus enhancing survival in the nest. Specifically, the hyper‐functioning noradrenergic locus coeruleus (LC) enables pups to learn rapid, robust preference for the caregiver. Conversely, a hypo‐functional amygdala appears to prevent the infant from learning aversions to the caregiver. Adult LC and amygdala functional emergence correlates with sensitive period termination. This study suggests the neonatal brain is not an immature version of the adult brain but is uniquely designed to optimize attachment to the caregiver. Although human attachment may not rely on identical circuitry, the work reviewed here suggests a new conceptual framework in which to explore human attachments, particularly attachments to abusive caregivers. © 2005 Wiley Periodicals, Inc. Dev Psychobiol 47: 230–242, 2005.
Blood pressure responses to feeding in infancy: Spin‐offs of serendipity
Authors: Myers Michael M. , Shair Harry N. , Cohen Morris
Published: October 2005

This article summarizes results from a program of research that has focused on understanding the characteristics of, and factors that shape, acute cardiovascular responses to feeding in infants. The work developed from behavioral observations in rats suggesting a linkage between variations in maternal behavior and adult blood pressure. However, the hypothesis that specific types of interactions, in particular those associated with feeding, might alter cardiovascular function was greatly influenced by a serendipitous observation made by Myron Hofer several years earlier. Myron discovered that nutrient availability is a key regulator of cardiovascular function in newborn rats. Our spin‐off studies established that, in newborn rats and human infants, ingestion of nutrient is associated with robust increases in heart rate and blood pressure. © 2005 Wiley Periodicals, Inc. Dev Psychobiol 47: 268–277, 2005.
I‐SceI meganuclease‐mediated transgenesis in Xenopus
Authors: Pan Fong Cheng , Chen Yonglong , Loeber Jana , Henningfeld Kristine , Pieler Tomas
Published: October 2005

Several experimental approaches have been described to generate transgenic frogs. Here, we report on the application of a novel method in Xenopus, making use of I‐SceI meganuclease. The characteristic feature of this endonuclease is that it has an extended recognition site of 18 bp, which is expected to exist only once in 7 × 1010 bp of random DNA sequences. Various reporter constructs flanked by two I‐SceI recognition sites were injected together with the I‐SceI meganuclease into one‐cell stage Xenopus embryos. We observed an overall transgenesis frequency of 10% or more under optimized condition. The injected genes were integrated into the genome and transmitted to F1 offspring. Southern blot analysis showed that between one and eight copies of the transgene were integrated. Meganuclease‐aided transgenesis, thus, provides a simple and highly efficient tool for transgenesis in Xenopus. Developmental Dynamics 235:247–252, 2006. © 2005 Wiley‐Liss, Inc.
Binding of Oxovanadium(IV) to Tripeptides Containing Histidine and Cysteine Residues and Its Biological Implication in the Transport of Vanadium and Insulin‐Mimetic Compounds
Authors: Garribba Eugenio , Micera Giovanni , Lodyga‐Chruscinska Elzbieta , Sanna Daniele , Sanna Gavino
Published: October 2005

The complexation of VIVO ion with three tripeptides of biological importance containing L‐histidine or L‐cysteine (HisGlyGly, GlyGlyHis and GlyGlyCys) has been studied. This study was performed in aqueous solution by the combined application of potentiometric and spectroscopic (electronic absorption and EPR) techniques. The results indicate that these oligopeptides, if a ligand‐to‐metal molar ratio of 10 or 15 is used, can keep VIVO ion in solution until the deprotonation of the amide group with the donor set (NH2, CO, Nimax) for HisGlyGly or (COO–, CO) for GlyGlyHis and GlyGlyCys. In all the systems, at pH values around neutrality, a VOLH–2 species is formed with an (NH2, N–, N–, COO–) donor set for HisGlyGly, (NH2, N–, N–, Nim) for GlyGlyHis and (NH2, N–,N–, S–) for GlyGlyCys. These species, and those with onedeprotonated amide group coordinated to the VIVO ion, can be detected by EPR spectroscopy. The N–(amide) contribution to the hyperfine coupling constant along the z axis, Az, depends on the total charge of the donor atoms in the equatorial plane. The participation of albumin in the transport of vanadium and insulin‐mimetic VIVO compounds is reconsidered based on these results. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Radio‐echo layering in West Antarctica: a spreadsheet dataset
Authors: Siegert Martin J. , Pokar Magdeline , Dowdeswell Julian A. , Benham Toby
Published: October 2005

Of the various information recovered from radio‐echo sounding (RES) of polar ice sheets, internal layering is currently under‐utilized by glaciologists, due in part to a lack of available data. Here, RES layering of the West Antarctic Ice Sheet, from the 1970s RES survey of approximately 70 per cent of this ice mass, is made available in a series of spreadsheets. Three types of internal layers are evident in the dataset. The first is continuous layers that have a stratigraphic appearance and can often be traced easily for hundreds of kilometres. The second is buckled layering, which also resembles stratigraphy and can sometimes be traced over tens of kilometres (although layer identification can often be difficult). The roughness of these layers is often greater than the bed at the same wavelength. The third is highly distorted or absent layering, which is not possible to trace laterally. Despite debate concerning the origin of RES layers, they are thought by most glaciologists to represent isochronous surfaces. The pattern of internal layering is potentially of importance to glaciologists for three reasons. (1) The position of undeformed layers below the ice surface is a function of accumulation rate, ice flow and basal melting conditions. Numerical modelling (including new ‘data assimilation’ techniques) could be used to discriminate between these processes, so revealing important information about the ice sheet and its environment. (2) Buckled layers are deformed by ice flow process, and so their occurrence can be related to the flow dynamics of the ice sheet. (3) Very buckled layers are often associated with ice stream flow, which allows their location to mark the positions of past and present fast‐flowing ice. Copyright © 2005 John Wiley & Sons, Ltd.
Differential effect of epigenetic alterations and genomic deletions of CDK inhibitors [p16(INK4a), p15(INK4b), p14(ARF)] in mantle cell lymphoma
Authors: Hutter Grit , Scheubner Miriam , Zimmermann Yvonne , Kalla Joerg , Katzenberger Tiemo , Hübler Karin , Roth Sabine , Hiddemann Wolfgang , Ott German , Dreyling Martin
Published: October 2005

Mantle cell lymphoma (MCL) is characterized by the chromosomal translocation t(11;14)(q13;q32), resulting in overexpression of CCND1 in the vast majority of cases. In addition, alterations of other cell‐cycle‐regulating signal pathways (CDKN2B/CDKN2A‐CCND1 and ARF‐MDM2‐TP53) are frequently observed. However, the hierarchy of promoter methylations and genomic alterations as well as the interaction with other cell‐cycle regulator CDKN1A is poorly understood. A complete methylation‐specific PCR coupled with direct sequencing of 71 MCL patient samples previously characterized for TP53 alterations, Ki67 expression by immunohistochemistry, and other genomic alterations was performed. In contrast to rare p16(INK4a) promoter methylation (9%), frequent p15(INK4b) (62%) and p14(ARF) (70%) promoter methylation was detectable in MCL. In an additional 16% of MCL cases, LOH for p16(INK4a) was detected. However, MCL cases with p15(INK4b) methylation tended to have lower proliferation (73% vs. 57%), and p15(INK4b) and p14(ARF) promoter methylation was also detected in normal stem cells. Therefore, epigenetic changes of those genes seem not to represent primary oncogenic mechanisms but physiological mechanisms of cell regulation. The rare p16(INK4a) promoter methylation and p16(INK4a) genetic alterations were directly correlated to cell proliferation and therefore are regarded as additional molecular alterations involved in the cell‐cycle dysregulation of MCL. © 2005 Wiley‐Liss, Inc.
[2 + 3]‐Cycloadditions of Phosphonodithioformate S‐Methanides with CS, NN, and CC Dipolarophiles
Authors: Mlostoń Grzegorz , Urbaniak Katarzyna , Gulea Mihaela , Masson Serge , Linden Anthony , Heimgartner Heinz
Published: October 2005

The reaction of the methyl (dialkoxyphosphinyl)‐dithioformates (= methyl dialkoxyphosphinecarbodithioate 1‐oxides) 10 with CH2N2 at − 65° in THF yielded cycloadducts which eliminated N2 between − 40 and − 35° to give the corresponding phosphonodithioformate S‐methanides ( =methylenesulfonium (dialkoxyoxidophosphino)(methylthio)methylides) 11 (Scheme 3). These reactive 1,3‐dipoles were intercepted by aromatic thioketones to yield 1,3‐dithiolanes. Whereas the reaction with thiobenzophenone (12b) led to the sterically more congested isomers 15 regioselectively, a mixture of both regioisomers was obtained with 9H‐fluorene‐9‐thione (12a). Trapping of 11 with phosphono‐ and sulfonodithioformates led exclusively to the sterically less hindered 1,3‐dithiolanes 16 and 18, respectively (Scheme 4). In addition, reactive CC dipolarophiles such as ethenetetracarbonitrile, maleic anhydride, and N‐phenylmaleimide as well as the NN dipolarophile dimethyl diazenedicarboxylate were shown to be efficient interceptors of 11 (Scheme 5).
Synthesis of New C(2)‐Substituted gluco‐Configured Tetrahydroimidazopyridines and Their Evaluation as Glucosidase Inhibitors
Authors: Shanmugasundaram Bhagavathy , Vasella Andrea
Published: October 2005

The gluco‐configured C(2)‐substituted tetrahydroimidazopyridines 8–14 were prepared and tested as inhibitors of the β‐glucosidases from Caldocellum saccharolyticum and from sweet almonds, and of the α‐glucosidase from brewer's yeast. All new imidazopyridines are nanomolar inhibitors of the β‐glucosidases and micromolar inhibitors of the α‐glucosidase. The 3‐phenylpropyl derivative 14 proved the strongest inhibitor of the Caldocellum β‐glucosidase (Ki = 0.9 nM), only slightly weaker than the known 2‐phenylethyl analogue 7, and the propyl derivative 13 is the strongest inhibitor of the sweet almond β‐glucosidases (Ki = 3.2 nM), again slightly weaker than 7. There is no strong dependence of the inhibition on the nature of the C(2)‐substituent and no clear correlation between the inhibitory strength of the known manno‐configured imidazopyridines 2–6 and the gluco‐analogues 8–12. While most manno‐imidazopyridines are competitive inhibitors, the gluco‐analogues proved non‐competitive inhibitors of the Caldocellum β‐glucosidase and mixed‐type or partial mixed‐type inhibitors of the sweet almond β‐glucosidases.
Chemical Constituents from Croton insularis
Authors: Graikou Konstantia , Aligiannis Nektarios , Chinou Ioanna , Skaltsounis Alexios‐Léandros , Tillequin François , Litaudon Marc
Published: October 2005

Three new clerodane‐type terpenoids, furocrotinsulolide A (1), furocrotinsulolide B (2), and crotinsulactone (3), as well as a new phenolic disaccharide (4) have been isolated from the aerial parts of Croton insularis, together with eight known compounds. Their structures were established by in‐depth 1D‐ and 2D‐NMR spectroscopy, mass spectroscopy, and quantum‐mechanical calculations.
Antifungal activity of DNA–lipid complexes and DNA–lipid films against Candida species
Authors: Inoue Y. , Fukushima T. , Hayakawa T. , Ogura R. , Kaminishi H. , Miyazaki K. , Okahata Y.
Published: October 2005

In this study amphiphilic lipids, DNA–lipid complexes, and DNA–lipid films were prepared, and their antifungal activity against Candida species was examined. The amphiphilic lipids were synthesized from a reaction of glycine or L‐alanine with n‐alkyl alcohol in the presence of p‐toluene sulfonic acid. DNA–lipid complexes, which were prepared by the simple mixing of DNA and amphiphilic lipids, were insoluble in water. Self‐standing, water‐insoluble DNA–lipid films were prepared by casting the DNA–lipid complexes from a chloroform/ethanol solution. The antifungal activities of the lipids and DNA–lipid complexes against the Candida species were evaluated by minimum inhibitory concentrations (MICs); those of DNA–lipid films were evaluated by the disk diffusion method. The seven kinds of lipids, DNA–lipid complexes, and DNA–lipid films showed antifungal activity, and no differences were seen in the antifungal activities between glycine and L‐alanine derivatives. The lipids, DNA–lipid complexes, and DNA–lipid films, which have shorter alkyl chain length in lipids, showed antifungal activity against all Candida species. However, the effect of antifungal activity against Candida species decreased with increased alkyl chain length in lipids. In this study, it was found that lipids, DNA–lipid complexes, and films with a decyl or dodecyl group exhibit more favorable antifungal activity. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Local delivery of bisphosphonate from coated orthopedic implants increases implants mechanical stability in osteoporotic rats
Authors: Peter Bastian , Gauthier Olivier , Laïb Samia , Bujoli Bruno , Guicheux Jérôme , Janvier Pascal , van Lenthe G. Harry , Müller Ralph , Zambelli Pierre‐Yves , Bouler Jean‐Michel , Pioletti Dominique P.
Published: October 2005

Patients with osteoporosis and joint disabilities represent a constant growing and challenging population to be treated in the musculoskeletal clinical field. Especially in the case of total hip arthroplasty, new solutions should be developed to compensate for the double negative factors, peri‐implant osteolysis, and osteoporotic bone loss, affecting the quality of implant outcome. The goal of this study was then to establish a proof of concept for orthopedic implant used as Zoledronate delivery in osteoporotic rats, and in particular, to verify if this approach could increase the initial implant stability. Twenty‐five female 6‐month‐old Wistar rats were ovariectomized 6 weeks before the implantation to induce osteoporosis. The animals were randomly separated in five groups representing the different Zoledronate concentrations in the HA coating: 0, 0.2, 2.1, 8.5, and 16 μg/implant. Histomorphometric measures and peri‐implant bone volume fraction were assessed and mechanical stability tests were performed. Bone volume fraction and biomechanical results clearly illustrate the positive effect of Zoledronate coated implants in the osteoporotic rats. A remarkable result was to show the existence of a window of Zoledronate content (0.2 to 8.5 μg/implant) in which the mechanical fixation of the implant increased. We were able to establish the proof of concept for orthopedic implants used as a drug delivery system in osteoporotic rats. The local bisphosphonate delivery from a calcium phosphate coating allowed increase of the mechanical fixation of an orthopedic implant. This study shows that orthopedic implants containing bisphosphonates could be beneficial for osteoporotic patients in need of a total joint replacement. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
A BAC library of the East African haplochromine cichlid fish Astatotilapia burtoni
Authors: Lang Michael , Miyake Tsutomu , Braasch Ingo , Tinnemore Deborah , Siegel Nicol , Salzburger Walter , Amemiya Chris T. , Meyer Axel
Published: October 2005

A BAC library was constructed from Astatotilapia burtoni, a haplochromine cichlid that is found in Lake Tanganyika, East Africa, and its surrounding rivers. The library was generated from genomic DNA of blood cells and comprises 96,768 individual clones. Its median insert size is 150 kb and the coverage is expected to represent about 14 genome equivalents. The coverage evaluation was based on genome size estimates that were obtained by flow cytometry. In addition, hybridization screens with five probes largely corroborate the above coverage estimate, although the number of clones ranged from 5 to 22 authenticated clones per single copy probe. The BAC library described here is expected to be useful to the scientific community interested in cichlid genomics as an important resource to gain new insights into the rapid evolution of the great species diversity of haplochromine cichlid fishes. J. Exp. Zool. (Mol. Dev. Evol.) 306B, 2006. © 2005 Wiley‐Liss, Inc.
Evolutionary transformations of fetal membrane characters in Eutheria with special reference to Afrotheria
Authors: Mess Andrea , Carter Anthony M.
Published: October 2005

Analysis of molecular data sets has provided new insights into higher‐level relationships of living Eutheria, including the recognition of Afrotheria as a novel taxon. This offers an opportunity to take a fresh look at the evolution of organ systems, including some that are little used in traditional systematics. In the present study, we attempted a reconstruction of the evolution of characters associated with placentation, the fetal membranes and the female reproductive tract. The evolutionary history of 21 characters has been traced, based on a current hypothesis of eutherian relationships, by applying the computer program MacClade. Accordingly, the analysis provides a first comprehensive interpretation of the stem species pattern of Eutheria. Of particular note, this pattern includes an endotheliochorial chorioallantoic placenta. The reconstructed pattern of Eutheria does not change in the basal nodes of the group. Thus, no character transformations occur on the stem lineages of Laurasiatheria or Euarchontoglires, and even Afrotheria has mostly plesiomorphic character conditions. However, two character transformations occur on the common stem lineage of Afrotheria and its sister taxon Xenarthra, i.e., amniogenesis by cavitation instead of folding and the precocial state of the newborn. In addition, we recognized one character transformation on the stem lineage of Afrotheria, i.e., the occurrence of a four‐lobed allantoic sac. Thus, contrary to previous assertions, it is possible to identify morphological characters that could be synapomorphic for this novel taxon. J. Exp. Zool. (Mol. Dev. Evol.) 306B, 2006. © 2005 Wiley‐Liss, Inc.