bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of maternal exposure to an aromatase inhibitor on sexual behaviour and neurochemical and endocrine aspects of adult male rat
Authors: Gerardin Daniela C. C. , Piffer Renata C. , Garcia Patrícia C. , Moreira Estefânia G. , Pereira Oduvaldo C. M.
Published: May 2008

The present study examined the effects of letrozole exposure during brain sexual differentiation on endocrine, behavioural and neurochemical parameters in male rat descendants. Pregnant female rats received 1 mg kg–1 day–1 letrozole or vehicle by oral gavage on gestational Days 21 and 22. Exposure to letrozole reduced anogenital distance in males on postnatal Day (PND) 22. At adulthood (PND 75), plasma testosterone levels and hypothalamic dopaminergic activity were increased, but sexual competence was impaired, because fewer successful sexual behaviours (mount, intromission and principally ejaculation) were observed. The impairment of reproductive function by prenatal exposure to an aromatase inhibitor reinforces the importance of adequate oestrogenic activity during perinatal sexual differentiation for complete masculinisation of the hypothalamus.
Cdx
gene deficiency compromises embryonic hematopoiesis in the mouse
Authors: Wang Yuan , Yabuuchi Akiko , McKinney-Freeman Shannon , Ducharme Danica M. K. , Ray Manas K. , Chawengsaksophak Kallayanee , Archer Trevor K. , Daley George Q.
Published: May 2008

Cdx
genes (
Cdx1
,
Cdx2
, and
Cdx4
) encode a family of
caudal
-related transcription factors that mediate anterior–posterior patterning during embryogenesis through
Hox
gene regulation. Homologues in the zebrafish have been shown to play key roles in blood formation. To define the role of
Cdx
genes during embryonic hematopoiesis in a mammalian system, we examined the hematopoietic potential of
Cdx
-deficient mouse embryonic stem cells (ESCs)
in vitro
and
in vivo
. Individual
Cdx
-deficient ESCs exhibited impaired embryonic hematopoietic progenitor formation and altered
Hox
gene expression, most notably for
Cdx2
deficiency. A more severe hematopoietic defect was observed with compound
Cdx
deficiency than loss of function of any single
Cdx
gene. Reduced hematopoietic progenitor formation of ESCs deficient in multiple
Cdx
genes could be rescued by ectopic expression of
Cdx4
, concomitant with partially restored
Hox
gene expression. These results reveal an essential and partially redundant role for multiple
Cdx
genes during embryonic hematopoiesis in the mouse.
A dicarboxylate/4-hydroxybutyrate autotrophic carbon assimilation cycle in the hyperthermophilic Archaeum
Ignicoccus hospitalis
Authors: Huber Harald , Gallenberger Martin , Jahn Ulrike , Eylert Eva , Berg Ivan A. , Kockelkorn Daniel , Eisenreich Wolfgang , Fuchs Georg
Published: May 2008

Ignicoccus hospitalis
is an anaerobic, autotrophic, hyperthermophilic Archaeum that serves as a host for the symbiotic/parasitic Archaeum
Nanoarchaeum equitans
. It uses a yet unsolved autotrophic CO
2
fixation pathway that starts from acetyl-CoA (CoA), which is reductively carboxylated to pyruvate. Pyruvate is converted to phosphoenol-pyruvate (PEP), from which glucogenesis as well as oxaloacetate formation branch off. Here, we present the complete metabolic cycle by which the primary CO
2
acceptor molecule acetyl-CoA is regenerated. Oxaloacetate is reduced to succinyl-CoA by an incomplete reductive citric acid cycle lacking 2-oxoglutarate dehydrogenase or synthase. Succinyl-CoA is reduced to 4-hydroxybutyrate, which is then activated to the CoA thioester. By using the radical enzyme 4-hydroxybutyryl-CoA dehydratase, 4-hydroxybutyryl-CoA is dehydrated to crotonyl-CoA. Finally, β-oxidation of crotonyl-CoA leads to two molecules of acetyl-CoA. Thus, the cyclic pathway forms an extra molecule of acetyl-CoA, with pyruvate synthase and PEP carboxylase as the carboxylating enzymes. The proposal is based on
in vitro
transformation of 4-hydroxybutyrate, detection of all enzyme activities, and
in vivo
-labeling experiments using [1-
14
C]4-hydroxybutyrate, [1,4-
13
C
2
], [U-
13
C
4
]succinate, or [1-
13
C]pyruvate as tracers. The pathway is termed the dicarboxylate/4-hydroxybutyrate cycle. It combines anaerobic metabolic modules to a straightforward and efficient CO
2
fixation mechanism.
ALIX-CHMP4 interactions in the human ESCRT pathway
Authors: McCullough John , Fisher Robert D. , Whitby Frank G. , Sundquist Wesley I. , Hill Christopher P.
Published: May 2008

The ESCRT pathway facilitates membrane fission events during enveloped virus budding, multivesicular body formation, and cytokinesis. To promote HIV budding and cytokinesis, the ALIX protein must bind and recruit CHMP4 subunits of the ESCRT-III complex, which in turn participate in essential membrane remodeling functions. Here, we report that the Bro1 domain of ALIX binds specifically to C-terminal residues of the human CHMP4 proteins (CHMP4A-C). Crystal structures of the complexes reveal that the CHMP4 C-terminal peptides form amphipathic helices that bind across the conserved concave surface of ALIX
Bro1
. ALIX-dependent HIV-1 budding is blocked by mutations in exposed ALIX
Bro1
residues that help contribute to the binding sites for three essential hydrophobic residues that are displayed on one side of the CHMP4 recognition helix (M/L/IxxLxxW). The homologous CHMP1–3 classes of ESCRT-III proteins also have C-terminal amphipathic helices, but, in those cases, the three hydrophobic residues are arrayed with L/I/MxxxLxxL spacing. Thus, the distinct patterns of hydrophobic residues provide a “code” that allows the different ESCRT-III subunits to bind different ESCRT pathway partners, with CHMP1–3 proteins binding MIT domain-containing proteins, such as VPS4 and Vta1/LIP5, and CHMP4 proteins binding Bro1 domain-containing proteins, such as ALIX.
A NOD2–NALP1 complex mediates caspase-1-dependent IL-1β secretion in response to
Bacillus anthracis
infection and muramyl dipeptide
Authors: Hsu Li-Chung , Ali Syed R. , McGillivray Shauna , Tseng Ping-Hui , Mariathasan Sanjeev , Humke Eric W. , Eckmann Lars , Powell Jonathan J. , Nizet Victor , Dixit Vishva M. , Karin Michael
Published: May 2008

NOD2, a NOD-like receptor (NLR), is an intracellular sensor of bacterial muramyl dipeptide (MDP) that was suggested to promote secretion of the proinflammatory cytokine IL-1β. Yet, the molecular mechanism by which NOD2 can stimulate IL-1β secretion, and its biological significance were heretofore unknown. We found that NOD2 through its N-terminal caspase recruitment domain directly binds and activates caspase-1 to trigger IL-1β processing and secretion in MDP-stimulated macrophages, whereas the C-terminal leucine-rich repeats of NOD2 prevent caspase-1 activation in nonstimulated cells. MDP challenge induces the association of NOD2 with another NLR protein, NALP1, and gel filtration analysis revealed the formation of a complex consisting of NOD2, NALP1, and caspase-1. Importantly,
Bacillus anthracis
infection induces IL-1β secretion in a manner that depended on caspase-1 and NOD2.
In vitro
, Anthrax lethal toxin strongly potentiated IL-1β secretion, and that response was NOD2 and caspase-1-dependent. Thus, NOD2 plays a key role in the
B. anthracis
-induced inflammatory response by being a critical mediator of IL-1β secretion.
An original adaptation of photosynthesis in the marine green alga
Ostreococcus
Authors: Cardol Pierre , Bailleul Benjamin , Rappaport Fabrice , Derelle Evelyne , Béal Daniel , Breyton Cécile , Bailey Shaun , Wollman Francis André , Grossman Arthur , Moreau Hervé , Finazzi Giovanni
Published: May 2008

Adaptation of photosynthesis in marine environment has been examined in two strains of the green, picoeukaryote
Ostreococcus
: OTH95, a surface/high-light strain, and RCC809, a deep-sea/low-light strain. Differences between the two strains include changes in the light-harvesting capacity, which is lower in OTH95, and in the photoprotection capacity, which is enhanced in OTH95. Furthermore, RCC809 has a reduced maximum rate of O
2
evolution, which is limited by its decreased photosystem I (PSI) level, a possible adaptation to Fe limitation in the open oceans. This decrease is, however, accompanied by a substantial rerouting of the electron flow to establish an H
2
O-to-H
2
O cycle, involving PSII and a potential plastid plastoquinol terminal oxidase. This pathway bypasses electron transfer through the cytochrome
b
6
f
complex and allows the pumping of “extra” protons into the thylakoid lumen. By promoting the generation of a large ΔpH, it facilitates ATP synthesis and nonphotochemical quenching when RCC809 cells are exposed to excess excitation energy. We propose that the diversion of electrons to oxygen downstream of PSII, but before PSI, reflects a common and compulsory strategy in marine phytoplankton to bypass the constraints imposed by light and/or nutrient limitation and allow successful colonization of the open-ocean marine environment.
Risk Factors for Infectious Spondylodiscitis in Patients Receiving Hemodialysis
Authors: Helewa Ramzi M. , Embil John M. , Boughen Cynthia G. , Cheang Mary , Goytan Michael , Zacharias James M. , Trepman Elly
Published: May 2008

A retrospective case-control and cohort analysis of hemodialysis patients was done to identify risk factors for spondylodiscitis. These risk factors included bacteremia, receipt of blood products, invasive procedures, and establishment of vascular access. The death rate was greater for case subjects than for control subjects (odds ratio, 2.7).
Fast electron driven Alfvén eigenmodes in the current rise in Alcator C-MOD
Authors: Snipes J.A. , Parker R.R. , Phillips P.E. , Schmidt A. , Wallace G.
Published: May 2008

The injection of 0.3–1 MW of lower hybrid current drive (LHCD) from the very start of the plasma drives a suprathermal electron tail that excites a series of bursting high frequency (100–700 kHz) instabilities in the current rise in Alcator C-Mod. These high frequency bursting modes have relatively small amplitudemeasured with poloidal field pick-up coils on outboard limiters. They are observed very early in the current rise with one to three bands of frequencies. The frequency at each burst corresponds very closely to the centre of the gap frequency for toroidal Alfvén eigenmodes (TAEs), ωTAE=vA/2qR, for integer and half integerqvalues ranging typically from 11 down to 5.5. Measured average hard x-ray photon energies in the range 20–35 keV are in reasonable agreement with the theoretically calculated fast electron energy that matches the precession drift resonance condition for exciting Alfvén eigenmodes.
Summary of the 17th International Atomic Energy Agency Technical Meeting on ‘Research Using Small Fusion Devices’
Authors: Varandas C.A.F. , Silva C. , Gribkov V.A. , Malaquias A. , Van Oost G.
Published: May 2008

This paper presents a summary of the recent results reported on several topics on magnetic confinement, dense magnetized plasmas and materials studies. The main topics covered on magnetic confinement devices are configuration studies, diagnostics developments, alternative fuelling techniques, turbulence and transport studies, confinement experiments, plasma facing materials, acquisition and control systems and integrated modelling. For the dense magnetized plasma devices results on development and commissioning of several devices (plasma focus, Z-pinch and plasma discharge type), material tests, scaling laws for plasma focus energy density from a few millijoule to megajoule, modelling of neutron and x-ray production mechanisms and fast diagnostic and signal formatting techniques were reported. Auxiliary heating systems for ITER, dedicated materials modelling and experimental studies relevant for several fusion applications and control and data acquisition systems have also been reported on in dedicated papers.
Efficient functional clustering of protein sequences using the Dirichlet process
Authors: Brown Duncan P.
Published: May 2008

Motivation: Automatic clustering of protein sequences is an important problem in computational biology. The recent explosion in genome sequences has given biological researchers a vast number of novel protein sequences. However, the majority of these sequences have no experimental evidence for their molecular function in the cell, and the responsibility for correctly annotating these sequences falls upon the bioinformatics community. Ideally, we would like to be able to group sequences of similar or identical molecular function in an automatic fashion, without relying on experimental evidence.

Results: In this article I present a novel probabilistic framework that models subfamilies within a known protein family. Given a multiple sequence alignment, the model uses Dirichlet mixture densities to estimate amino acid preferences within subfamily clusters, and places a Dirichlet process prior on the overall set of clusters. Based on results from several datasets, the model breaks data accurately into functional subgroups.

Availability: The algorithm is implemented as c++ software available at bpg-research.berkeley.edu/~duncanb/dpcluster/

Contact:  duncan_brown@merck.com

Supplementary information:  Supplementary data are available at Bioinformatics online.
Ontologizer 2.0—a multifunctional tool for GO term enrichment analysis and data exploration
Authors: Bauer Sebastian , Grossmann Steffen , Vingron Martin , Robinson Peter N.
Published: May 2008

Summary: The Ontologizer is a Java application that can be used to perform statistical analysis for overrepresentation of Gene Ontology (GO) terms in sets of genes or proteins derived from an experiment. The Ontologizer implements the standard approach to statistical analysis based on the one-sided Fisher's exact test, the novel parent–child method, as well as topology-based algorithms. A number of multiple-testing correction procedures are provided. The Ontologizer allows users to visualize data as a graph including all significantly overrepresented GO terms and to explore the data by linking GO terms to all genes/proteins annotated to the term and by linking individual terms to child terms.

Availability: The Ontologizer application is available under the terms of the GNU GPL. It can be started as a WebStart application from the project homepage, where source code is also provided: http://compbio.charite.de/ontologizer

Requirements: Ontologizer requires a Java SE 5.0 compliant Java runtime engine and GraphViz for the optional graph visualization tool.

Contact:  sebastian.bauer@charite.de; peter.robinson@charite.de
What's in the Literature?
Authors: Simmons Zachary
Published: May 2008

I have been the beneficiary for many years of the wisdom that my colleague, Dr. Lawrence Phillips, has distilled into this section through his astute summaries of the neuromuscular literature. It is with enthusiasm and gratitude, but with some trepidation, that I assume this responsibility at the request of the Editor in Chief as Dr. Phillips moves on to other responsibilities. I hope that readers continue to find this section useful.
Painful Brachial Plexopathies in SEPT9 Mutations: Adverse Outcome Related to Comorbid States
Authors: Hoque Romy , Schwendimann Robert N , Kelley Roger E , Bien-Willner Ricardo , Sivakumar Kumaraswamy
Published: May 2008

Hereditary neuralgic amyotrophy (HNA), an autosomal dominant disorder associated with SEPT9 mutation located on chromosome 17q25, causes recurrent painful weakness with sensory disturbances in a brachial distribution. We present electrophysiological, clinical phenotype, and molecular genetic data of three members from a family with HNA with the C262T SEPT9 mutation. The degree of motor weakness and recovery is variable within this family. Severity and recovery from motor deficits may have been a function of comorbid medical conditions. To our knowledge, this is the first report to confirm SEPT9 mutation in a family with suspected HNA.
Chronic Inflammatory Demyelinating Polyradiculoneuropathy Associated With Multiple Sclerosis
Authors: Sharma Khema R , Saadia Daniela , Facca Alicia G , Bhatia Rita , Ayyar D Ram , Sheremata William
Published: May 2008

Objective:

To describe temporal profile of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) in patients with definite, relapsing multiple sclerosis (MS).

Background:

Peripheral demyelinating neuropathy has been rarely reported in association with central nervous system demyelinating disorder indistinguishable from MS.

Methods:

In addition to usual diagnostic studies for CIDP and MS in all 5 patients, we studied proximal segments of nerves using deep tendon reflex latency measurements of biceps reflex, patellar reflex, and ankle reflex.

Results:

All patients with MS subsequently (4-22 years) developed definite CIDP. Two of these patients developed multiple cranial nerve and spinal root enhancement on subsequent imaging without new intraparenchymal enhancement after a diagnosis of CIDP. The deep tendon reflex latencies were prolonged at more than 2 sites in all patients. Cerebral spinal fluid protein increased (70 ± 19 to 144.8 ± 17.4 mg/dL, P = 0.0001) at time of diagnosis of CIDP. Clinical improvement was observed in all patients after intravenous immunoglobulin therapy.

Conclusions:

When patients with MS develop CIDP, manifestations of central and peripheral disease involvement seem to respond to intravenous immunoglobulin. These cases suggest that there may be common antigenic targets in central and peripheral nervous system in this subset of patients.
Pompe Disease: A Review of the Current Diagnosis and Treatment Recommendations in the Era of Enzyme Replacement Therapy
Authors: Katzin Lara W , Amato Anthony A
Published: May 2008

Pompe disease, or glycogen storage disease type II, is a rare autosomal recessive disorder caused by mutations in the gene that encodes for α-glucosidase. Presentation in infancy is associated with respiratory failure, cardiomyopathy, and severe muscle weakness. Juvenile- or adult-onset cases typically present with proximal muscle weakness and are associated with respiratory insufficiency or exertional dyspnea. Treatment, until recently, was focused on supportive measures, and infants diagnosed with Pompe disease usually died within the first year of life. The recent development of recombinant α-glucosidase has dramatically improved the life expectancy and quality of life of infantile-onset disease with improvements in respiratory and motor function observed in juvenile- or adult-onset cases. This review focuses on the presentation, pathogenesis, diagnosis, and treatment recommendations for Pompe disease in this new era of enzyme replacement therapy.
What's in the Literature?
Authors: Simmons Zachary
Published: May 2008

Because our readership is varied, I have tried to choose articles that span the broad scope of neuromuscular diseases, including disorders of the motor neuron, peripheral nerve, neuromuscular junction, and muscle. Of course there are many more articles published during a 3-month period of time than can be reviewed in this space, but I found the ones below particularly interesting and hope you will too.
Transatlantic migration and deep mid-ocean diving by basking shark
Authors: Gore Mauvis A , Rowat David , Hall Jackie , Gell Fiona R , Ormond Rupert F
Published: May 2008

Despite being the second largest fish, basking sharks (
Cetorhinus maximus
) have been assumed to remain in discrete populations. Their known distribution encompasses temperate continental shelf areas, yet until now there has been no evidence for migration across oceans or between hemispheres. Here we present results on the tracks and behaviour of two basking sharks tagged off the British Isles, one of which released its tag off Newfoundland, Canada. During the shark's transit of the North Atlantic, she travelled a horizontal distance of 9589 km and reached a record depth of 1264 m. This result provides the first evidence for a link between European and American populations and indicates that basking sharks make use of deep-water habitats beyond the shelf edge.
Effects of study task on the neural correlates of source encoding
Authors: Park Heekyeong , Uncapher Melina R. , Rugg Michael D.
Published: May 2008

The present study investigated whether the neural correlates of source memory vary according to study task. Subjects studied visually presented words in one of two background contexts. In each test, subjects made old/new recognition and source memory judgments. In one study test cycle, study words were subjected to animacy judgments, whereas in another cycle the study task required syllable judgments. Functional magnetic resonance imaging (fMRI) was employed to contrast the neural activity elicited by study words that attracted accurate source judgments on the later memory test, as opposed to words for which source judgments were incorrect or for which source information was unavailable. In both tasks, relative to words for which source memory failed, study words that were later assigned to the correct source elicited enhanced activity in ventral extrastriate cortex. In addition to these common effects of subsequent source memory, additional effects were observed that were selective for each study task. The present findings add weight to the proposal that neural activity supporting successful episodic memory encoding is a reflection of both the online processing engaged by an episode as it is experienced, and the demands imposed by the later retrieval task.
Early events in protein folding: Is there something more than hydrophobic burst?
Authors: Camilloni Carlo , Sutto Ludovico , Provasi Davide , Tiana Guido , Broglia Ricardo A.
Published: May 2008

The presence of native contacts in the denatured state of many proteins suggests that elements of the biologically active structure of these molecules are formed during the initial stage of the folding process. The rapidity with which these events take place makes it difficult to study them in vitro, but, by the same token, suitable for studies in silico. With the help of all‐atom, explicit solvent, molecular dynamics simulations we have followed in time, starting from elongated structureless conformations, the early events in the folding of src‐SH3 domain and of proteins G, L, and CI2. It is observed that within the first 50 ns two important events take place, essentially independent of each other: hydrophobic collapse and formation of a few selected native contacts. The same contacts are also found in simulations carried out in the presence of guanidinium chloride in order to reproduce the conditions used to characterize experimentally the denatured state and testify to the fact that these contacts are to be considered a resilient characterizing property of the denaturated state.
Feeding birds in our towns and cities: a global research opportunity
Authors: Jones Darryl N. , James Reynolds S.
Published: May 2008

Wild bird feeding is one of the most common forms of human‐wildlife interactions in the Western world. Originally a practice providing nutritional assistance to over‐wintering birds, especially in more northern latitudes, birds throughout the cities of the world are now provided with considerable amounts and a variety of foods year‐round. Despite the global nature of the practice, remarkably little is known about the outcomes and implications of what may be seen as a supplementary feeding experiment on a massive scale. Although many claims are made about the benefits of feeding, there are growing concerns about the spread of disease, poor nutrition, risk of dependency and many other important issues. Constructive debate among increasingly vigorous proponents and opponents is currently constrained by a lack of reliable information. Here we argue that bird feeding provides an important, if challenging, opportunity for fundamental research in urban ecology.
Characterization of a 320‐kb region containing the HEXA gene on bovine chromosome 10 and analysis of its association with BSE susceptibility
Authors: Juling K. , Schwarzenbacher H. , Frankenberg U. , Ziegler U. , Groschup M. , Williams J. L. , Fries R.
Published: May 2008

Bovine spongiform encephalopathy (BSE) belongs to a group of neurodegenerative diseases known as transmissible prion diseases. Recently, variants in the promoter region of the prion protein (PRNP) gene have been shown to have a considerable effect on the susceptibility to BSE. However, a previous genome scan revealed other putative BSE‐susceptibility loci. Here, we analysed such a region on BTA10, which contains the functional candidate gene HEXA. Three hundred and twenty kilobases that, besides HEXA, also contain ARIH1, BRUNOL6 and PARP6 were characterized and screened for polymorphisms. Genotyping of 38 SNPs in Holstein–Friesian animals from the UK (350 diseased and 270 controls) revealed two intronic SNPs that were associated with BSE incidence, with experiment‐wise P‐values of 3.5 × 10−3 and 7.7 × 10−3 respectively. Both SNPs were in strong linkage disequilibrium and the rare alleles had a protective effect. These alleles were contained in a haplotype dubbed ‘UK‐protective’ that was significantly overrepresented in the controls with a permuted P‐value of 2 × 10−3. An association study in German Holstein animals (73 diseased and 627 controls) revealed an opposite effect of the ‘UK‐protective’ haplotype in this population, i.e. it was overrepresented in the diseased animals, although not significant after correction for multiple testing. These findings indicate a causal variant for BSE susceptibility on BTA10 in linkage disequilibrium with the markers studied. Candidate gene analyses of the surrounding region and additional association studies will help to clarify the origin of the protective effects and to identify causal variants for BSE susceptibility on BTA10.
Hyaluronan–CD44 pathway regulates orientation of mitotic spindle in normal epithelial cells
Authors: Fujiwara Takeshi , Kawakatsu Tomomi , Tayama Sayaka , Kobayashi Yasuyo , Sugiura Nobuo , Kimata Koji , Takai Yoshimi
Published: May 2008

Orientation of mitotic spindle and cell division axis can impact normal physiological processes, including epithelial tissue branching and neuron generation by asymmetric cell division. Microtubule dynamics and its interaction with cortical proteins regulate the orientation of mitotic spindle axis. However, the nature of extracellular signals that control proper orientation of mitotic spindle axis is largely unclear. Here, we show that signals from two distinct surface contact, “bi‐surface‐contact,” sites are required for the orientation of mitotic spindle axis in normal epithelial cells. We identified apical and basal surface‐membrane as required bi‐surface‐contact sites. We showed that high molecular weight (HMW) hyaluronan (HA)–CD44 signaling from the apical surface‐membrane regulated the orientation of mitotic spindle axis to align parallel to the basal extracellular matrix (ECM). The same effect was achieved by fibronectin–integrin αvβ6 signaling from the basal surface‐membrane or by inhibition of ROCK activity. On the contrary, HMW HA–CD44 signaling from the basal surface‐membrane regulated the orientation of mitotic spindle axis to align oblique‐perpendicular to the basal ECM. We also found that microtubule dynamics is required for HMW HA–CD44 mediated regulation of mitotic spindle orientation. Our findings thus provide a novel mechanism for the regulation of mitotic spindle orientation.
hScrib, a human homologue of Drosophila neoplastic tumor suppressor, is a novel death substrate targeted by caspase during the process of apoptosis
Authors: Sone Kenbun , Nakagawa Shunsuke , Nakagawa Keiichi , Takizawa Shin , Matsumoto Yoko , Nagasaka Kazunori , Tsuruga Tetsushi , Hiraike Haruko , Hiraike‐Wada Osamu , Miyamoto Yuichiro , Oda Katsutoshi , Yasugi Toshiharu , Kugu Koji , Yano Tetsu , Taketani Yuji
Published: May 2008

hScrib, human homologue of Drosophila neoplastic tumor suppressor, was identified as a target of human papillomavirus E6 oncoprotein for the ubiquitin‐mediated degradation. Here, we report that hScrib is a novel death substrate targeted by caspase. Full‐length hScrib was cleaved by caspase during death ligands‐induced apoptosis, which generates a p170 C‐terminal fragments in Hela cells. In vitro cleavage assay using recombinant caspases showed that hScrib is cleaved by the executioner caspases. DNA damage‐induced apoptosis caused loss of expression of full‐length hScrib, which was recovered by addition of capase‐3 inhibitor in HaCat cells. TUNEL positive apoptotic cells, which were identified 4 h after UV irradiation in HaCat cells, showed loss of hScrib expression at the adherens junction. Mutational analysis identified the caspase‐dependent cleavage site of hScrib at the position of Asp‐504. Although MDCK cells transfected with GFP‐fused wild‐type hScrib showed loss of E‐cadherin expression and shrinkage of cytoplasm by UV irradiation, cells transfected with hScrib with Ala substitution of Asp‐504 showed resistance to caspase‐dependent cleavage of hScrib and intact expression of E‐cadherin. These results indicate that caspase‐dependent cleavage of hScrib is a critical step for detachment of cell contact during the process of apoptosis.
Patterns in vegetation and sedimentation during the Weichselian Late‐glacial in north‐eastern Germany
Authors: De Klerk Pim
Published: May 2008

Aim  To identify and interpret spatial patterns of vegetation and sedimentation during the Weichselian Late‐glacial.

Location  North‐eastern Germany and the adjacent fringe of north‐western Poland.

Methods  An inspection and comparison of palynological data from c. 150 sites.

Results  Open Vegetation phase I (Oldest Dryas = earlier part of the Meiendorf, 12,900–12,450 14C bp) and the Hippophaë phase (Bølling = later part of the Meiendorf; 12,450–12,000 bp) were rather homogeneous palynologically in the study area. Open Vegetation phase II (Older Dryas; 12,000–11,900 bp) is strongly recorded in the northern part of the study area with relatively thick sediments (suggesting severe soil erosion), but it can hardly be traced 200 km further to the south. This is attributed to sea buckthorn (Hippophaë) shrubs persisting longer in the south due to higher temperatures, to Betula forests expanding earlier under the influence of a more humid climate or to a generally denser vegetation independent of the behaviour of Hippophaë and Betula. During the late‐glacial Betula/Pinus forest phase (Allerød; 11,900–11,000 bp), pine (Pinus) forests dominated in the southern regions, whereas birch (Betula) forests prevailed in the north. Open Vegetation phase III (Younger Dryas; 11,000–10,000 bp) was characterized by heathlands in the northern regions with scattered birches and with sedimentation dominated by in‐washed silicates. In the south, pine parklands occurred with sedimentation dominated by local primary production which had markedly decreased after the previous warmer vegetation phase.

Main conclusions  The differences in vegetation and sedimentation during the open vegetation phases are attributed to a colder climate in the north than in the south, probably related to a climatic gradient between the ice‐free continental central Europe and the decaying Scandinavian ice sheet. The vegetation patterns during the late‐glacial Betula/Pinus forest phase are attributed to edaphic differences between the predominantly till plains in the northern part of the study area and the prevailing sandy outwash plains and Urstromtäler of the southern regions.
Sex Steroids and Cognitive Function
Authors: Luine V. N.
Published: May 2008

Gonadal hormones, most notably oestradiol, enhance some aspects of cognitive function in animal and human models. However, the demonstrated effects are often not large and inconsistent across studies. Nonetheless, because increased numbers of women are living longer in a state of oestrogen deprivation, research on this topic continues to be important. This review traces major developments concerning hormonal influences on cognition and provides some insights from recent studies that may be fruitful for future research.
Mathematical Modelling in Neuroendocrinology
Authors: Leng G. , MacGregor D. J.
Published: May 2008

In neuroendocrinology, mathematical modelling is about formalising our understanding of the behaviour of the complex biological systems with which we deal. Formulating our explanations mathematically ensures their logical consistency, and makes them open to structured analysis; it is a stringent test of their intellectual coherence. In addition, however, modellers are seeking to extend our understanding in new ways, by seeking novel, simple explanations for complex behaviour. Here we discuss some styles of modelling as they have been applied to neuroendocrine systems, and discuss some of their strengths and limitations.
A pilot study:sodium urate synovitis as an acute model of inflammatory response using objective and subjective criteria to evaluate arthritic pain in cats
Authors: CARROLL G. L. , NARBE R. , PETERSON K. , KERWIN S. C. , TAYLOR L. , DeBOER M.
Published: May 2008

Sodium urate (SU) synovitis was evaluated as a model for feline arthritic pain using a placebo‐ and positive‐controlled (meloxicam) randomized blinded controlled single crossover design. Monosodium urate crystals [20 mg (1 mL) rod‐shaped] were injected into alternate stifles of trained anesthetized cats (n = 3) with a 28 day washout.

During the first trial phase, two cats received meloxicam (0.1 mg/kg, PO), a nonsteroidal anti‐inflammatory drug (NSAID), for three days before and on the day of SU injection; the third cat received placebo. Treatments and stifles were switched for the second trial. Total force, contact pressure and area of the fore and hind limbs were measured using a pressure mat one day and 0.5 h before, and 2, 4, 6, 8, 10, 24, and 30 h post‐SU injection. Skin temperature, joint circumference, analgesia, lameness, and visual analogue scale (VAS) pain scores, were measured at the same times. Comparisons were made for each time and for areas under the curve (AUC) using original and change from baseline;P < 0.05 was significant. Significant differences in force mat data and subjective data were found for the hind limb data (total force and total contact pressure at 6, 10, and 30 h; analgesia and VAS for pain at 4 h; lameness at 10, 24, and 30 h) and for AUC0→24hand AUC0→30h(total force, total contact pressure, and mean lameness score) and for differences from BL AUC0→10h(total contact area) and AUC0→24h(total contact area and mean lameness score) and AUC0→30h(total force, total contact area, and mean lameness). No cats required rescue analgesia.

Injection of 1 mL of monosodium urate into the stifle of a cat causes moderate transitory pain and was suitable for assessing analgesic efficacy of an NSAID with a pressure mat and subjective criteria.
Twenty‐four hour spatiotemporal mapping of colonic propagating sequences provides pathophysiological insight into constipation
Authors: Dinning P. G. , Szczesniak M. M. , Cook I. J.
Published: May 2008

Abstract  Colonic propagating sequences (PS)s are a major determinant of luminal propulsion. A global appreciation of spatiotemporal patterning of PSs requires evaluation of 24 h pan‐colonic recordings, a difficult task given that PSs are relatively infrequent events that are not uniformly distributed throughout the colon. Here we developed a means of space‐time‐pressure ‘mapping’ in a condensed format, 24 h of colonic recording in such a manner that readily permits an overall view of colonic antegrade and retrograde colonic PSs within a single figure. Such graphical representation readily permits appreciation and identification of aberrant patterns in severe constipation and may be an important clinical and research tool in the assessment of colonic motor disorders.
Physiological and cytological mechanisms of silicon‐induced resistance in rice against blast disease
Authors: Cai Kunzheng , Gao Dan , Luo Shiming , Zeng Rensen , Yang Jianyuan , Zhu Xiaoyuan
Published: May 2008

Rice (Oryza sativa L.) blast disease caused by Magnaporthe grisea is one of the most destructive diseases in the rice‐growing areas of the world. Silicon is an important nutritional element especially for rice. Two near‐isogenic lines of rice with different resistance to blast disease, i.e. CO39 (susceptible) and C101LAC (Pi‐1) (resistant), were selected to determine the effects of Si amendment on the severity and incidence of rice blast disease. The physiological and cytological mechanisms involved in the induced disease resistance by silicon were investigated. Exogenous Si application at a concentration of 2 mM reduced the disease index by 45% for CO39 and 56% for C101LAC (Pi‐1). Si application alone did not change lignin content and the activities of defense‐related enzymes including peroxidase (POD), polyphenol oxidase (PPO) and phenylalanine ammonia‐lyase (PAL) in rice leaves of both isogenic lines. However, after inoculation with M. grisea, Si‐treated rice plants significantly increased the activities of POD, PPO and PAL in leaves of both isogenic lines. Si and lignin content were also significantly increased in Si‐treated inoculated seedlings. Environmental scanning electron microscope observations revealed that Si amendment resulted in higher Si deposit on dumbbell bodies in the rice leaves and silicon papilla accumulation on the guard cell of stoma. These results suggest that silicon‐induced defense response and cell silicification of rice leaves altogether contribute to the silicon‐induced rice resistance to blast disease.
The FRO2 ferric reductase is required for glycine betaine’s effect on chilling tolerance in Arabidopsis roots
Authors: Einset John , Winge Per , Bones Atle M. , Connolly Erin L.
Published: May 2008

FRO2 (At1g01580) codes for an NADPH‐dependent ferric reductase in plasma membranes of root epidermal cells with a demonstrated role in iron uptake by plants. Ferric reductase activity has been shown to be the rate‐limiting step for iron uptake in strategy I plants like Arabidopsis and in rice, but it has been unclear whether FRO genes have other physiological functions. We hypothesized that FRO2 was involved in chilling stress tolerance because its expression was upregulated by treatment of plants with glycine betaine (GB), a chemical that prevents reactive oxygen species (ROS) signaling in chilling stress. This idea was confirmed by showing that the FRO2 null mutant frd1‐1 failed to respond to GB in chilling assays either in relation to root growth recovery or inhibition of ROS accumulation. Measurements of ferric reductase activity in wild‐type plants treated with GB before chilling showed no significant GB effect compared with controls. In addition, 35S‐FRO2 transgenics with elevated mRNA levels did not have improved chilling tolerance. However, ferric reductase activity in wild‐type plants or 35S‐FRO2 transgenics pretreated with GB was several‐fold higher after chilling compared with non‐pretreated controls. These experiments identify a new physiological function for FRO2, i.e. blocking ROS accumulation during chilling. They also suggest that GB has a major effect on FRO2 activity posttranscriptionally in the cold.
Changes in aquaporin gene expression and magnetic resonance imaging of water status in peach tree flower buds during dormancy
Authors: Yooyongwech Suravoot , Horigane Akemi K , Yoshida Mitsuru , Yamaguchi Masami , Sekozawa Yoshihiro , Sugaya Sumiko , Gemma Hiroshi
Published: May 2008

The movement of cellular water accompanies changes in growth within dormant buds. To further understand this process, accumulation of tonoplast δTIP1 and plasma membrane PIP2 aquaporin transcripts was measured by quantitative reverse transcriptase–polymerase chain reaction and the water dynamics in dormant peach (Prunus persica L.) flower buds was studied by magnetic resonance imaging. Proton density (PD), spin–spin relaxation time (T2) and apparent diffusion coefficient (ADC) were used to observe water dynamics during dormancy. The expression of δTIP1 and PIP2 aquaporins, PD and T2 in the upper part of the bud including primordia, in the basal part of the bud and the bud trace increased earlier in the low‐chill cultivar ‘Coral’ than in the high‐chill cultivar ‘Kansuke Hakuto,’ reflecting the difference in timing for the end of endodormancy in the two cultivars. δTIP1 mRNA accumulated mainly in the basal part of the bud, whereas PIP2 mRNA was detected mainly in the upper part. These findings may reflect the activation of inter‐ and intracell communication through membrane transport properties of aquaporins resulting in a gradual increase in water content to that required for bud activity at the end of endodormancy. An apparent decrease in the expression of δTIP1 and PIP2 mRNAs was, however, observed in late winter in some portions of the buds of both cultivars just before sprouting.
Differentiation of morphology, genetics and electric signals in a region of sympatry between sister species of African electric fish (Mormyridae)
Authors: LAVOUÉ S. , SULLIVAN J. P. , ARNEGARD M. E. , HOPKINS C. D.
Published: May 2008

Mormyrid fishes produce and sense weak electric organ discharges (EODs) for object detection and communication, and they have been increasingly recognized as useful model organisms for studying signal evolution and speciation. EOD waveform variation can provide important clues to sympatric species boundaries between otherwise similar or morphologically cryptic forms. Endemic to the watersheds of Gabon (Central Africa), Ivindomyrus marchei and Ivindomyrus opdenboschi are morphologically similar to one another. Using morphometric, electrophysiological and molecular characters [cytochrome b sequences and amplified fragment length polymorphism (AFLP) genotypes], we investigated to what extent these nominal mormyrid species have diverged into biological species. Our sampling covered the known distribution of each species with a focus on the Ivindo River, where the two taxa co‐occur. An overall pattern of congruence among datasets suggests that I. opdenboschi and I. marchei are mostly distinct. Electric signal analysis showed that EODs of I. opdenboschi tend to have a smaller initial head‐positive peak than those of I. marchei, and they often possess a small third waveform peak that is typically absent in EODs of I. marchei. Analysis of sympatric I. opdenboschi and I. marchei populations revealed slight, but significant, genetic partitioning between populations based on AFLP data (FST ≈ 0.04). Taken separately, however, none of the characters we evaluated allowed us to discriminate two completely distinct or monophyletic groups. Lack of robust separation on the basis of any single character set may be a consequence of incomplete lineage sorting due to recent ancestry and/or introgressive hybridization. Incongruence between genetic datasets in one individual, which exhibited a mitochondrial haplotype characteristic of I. marchei but nevertheless fell within a genetic cluster of I. opdenboschi based on AFLP genotypes, suggests that a low level of recent hybridization may also be contributing to patterns of character variation in sympatry. Nevertheless, despite less than perfect separability based on any one dataset and inconclusive evidence for complete reproductive isolation between them in the Ivindo River, we find sufficient evidence to support the existence of two distinctive species, I. opdenboschi and I. marchei, even if not ‘biological species’ in the Mayrian sense.
Expression of Oestrogen Receptor α During Development of the Skeleton in Mice Fetuses: Immunohistochemical Study
Authors: Barle E. Lovsin , Pogacnik A. , Zabavnik J.
Published: May 2008

Sequential pattern of ossification and expression of oestrogen receptor α (ERα) during development of the skeleton in male and female mice fetuses was investigated. Twenty‐seven mice fetuses of gestational age between 14.5 and 18.5 days post coitum (p.c.) were examined by haematoxylin–eosin and toluidine blue staining to determine the ossification. The presence of ERα was detected by immunostaining using ERα‐specific antibodies. Ossification centres were determined in fetuses of 14.5 days p.c. of both sexes in the base of skull, ribs and front limbs, while in the mandible ossification was observed only in female fetuses at that age. ERα was found in all investigated tissues in which the occurrence of ossification centres was determined. ERα was first detected in some tissues involved in ossification at 14.5 days p.c. in fetuses of both genders. There were some minor gender differences in the pattern of ERα expression. ERα was localized in the metatarsal chondrogenic condensations at 14.5 days p.c. and in phalangeal chondrocytes at 17.5 and 18.5 days p.c. only in females. ERα‐positive osteogenic cells at 14.5 days p.c. in the mandible were seen only in females. At 16.5 days p.c. male but not female fetuses expressed ERα in the vertebrae. Our findings support the view that ERα protein is found in the tissues that undergo bone formation and that ERα expression in these tissues shows only minor gender differences in mice fetuses.
Quantitative Assessment of Renal Cortical Echogenicity in Clinically Normal Cats
Authors: Yabuki A. , Endo Y. , Sakamoto H. , Nagayoshi T. , Matsumoto M. , Suzuki S.
Published: May 2008

In this study, we assessed the renal cortical echogenicity of clinically normal adult cats by histogram analysis to obtain basic ultrasonographic data. Ultrasound images were taken under the following sets of conditions: (1) high contrast and low gain setting using a convex probe, (2) low contrast and high gain setting using a convex probe, (3) high contrast and low gain setting using a linear probe and (4) low contrast and high gain setting using a linear probe. Echogenicity of the region of interest (ROI) in the right and left renal cortices, liver and spleen was determined by histogram analysis; kidney/spleen (Kid/Sp) and kidney/liver (Kid/Liv) echogenicity ratios were calculated. Kid/Sp and Kid/Liv values varied among different ROI sites in the kidney when obtained using the convex probe, but were constant when obtained using the linear probe. Kid/Sp measured in the middle sites of the kidney showed similar values for the different settings; however, Kid/Liv differed between probes. The present findings suggest that determination of Kid/Sp using a linear probe is a feasible method for quantitative evaluation of renal cortical echogenicity in cats.
Root recovery rates for Phytophthora cinnamomi and rate of symptom development from root rot on Abies fraseri trees over 7 years
Authors: Griffin G. J. , Reaver D. , Osborne C. K. , Yancey M. M.
Published: May 2008

Phytophthora root rot on Abies fraseri trees was monitored from 2001 to 2007 within the disease front of a 12‐year‐old Virginia plantation where trees had been dying of the disease since 1994. After a slow increase in early foliage symptom development from July 2001 to September 2002, the frequency of A. fraseri trees with early symptoms accelerated for about 15 months. While the slow increase occurred during a 18.7% lower than normal rainfall period and the acceleration occurred during a 31.2% higher than normal rainfall period, the percentage of trees with early symptoms continued to increase during the mid‐winter months (December–February) when the estimated mean minimum daily soil temperature (25 cm depth) was unfavourable (<10°C) to Phytophthora cinnamomi pathogenic activity. The time required for trees to progress from early foliage symptoms to completely dead foliage, from November 2000 to October 2007, was highly variable, ranging from 4 to 35 months. Root recovery rates for P. cinnamomi, assayed on a selective medium, were 6.4 times greater for symptomatic foliage trees than for asymptomatic foliage trees in this deep, silt‐loam soil. Following an atypical cold period in February 2007, when the mean minimum daily soil temperature was 0.8°C, symptomatic roots yielded only a low level of germinable propagules of P. cinnamomi. Further, during an atypical midsummer in 2007 (June–August), when the soil water potential was at or below −9 bars for 68 of 92 days, symptomatic roots yielded no germinable propagules of P. cinnamomi. Addition of thiophanate‐methyl to the selective medium aided P. cinnamomi isolation by inhibiting many undesired pythiaceous colonies growing from symptomatic roots.