bluuebunny/crossref_metadata_2025 huggingface dataset:
Neonatal erythropoiesis and subsequent anemia in HIV-positive and HIV-negative Zimbabwean babies during the first year of life: a longitudinal study
Authors: Miller Melissa F , Humphrey Jean H , Iliff Peter J , Malaba Lucie C , Mbuya Nkosinathi V ,   the ZVITAMBO Study Group, Stoltzfus Rebecca J
Published: January 2006

Background

Anemia is common in HIV infection and independently associated with disease progression and mortality. The pathophysiology of HIV-related anemia is not well understood especially in infancy.

Methods

We conducted a longitudinal cohort study nested within the Zimbabwe Vitamin A for Mothers and Babies Project. We measured hemoglobin, erythropoietin (EPO), serum transferrin receptor (TfR) and serum ferritin at 6 weeks, 3 and 6 months of age and hemoglobin at 9 and 12 months in 3 groups of randomly selected infants: 136 born to HIV-negative mothers, and 99 born to HIV-positive mothers and who were infected themselves by 6 weeks of age, and 324 born to HIV-positive mothers but who did not become infected in the 6 months following birth.

Results

At one year of age, HIV-positive infants were 5.26 (adjusted odds ratio, P < 0.001) times more likely to be anemic compared to HIV-negative infants. Among, HIV-negative infants, EPO was or tended to be inversely associated with hemoglobin and was significantly positively associated with TfR throughout the first 6 months of life; TfR was significantly inversely associated with ferritin at 6 months; and EPO explained more of the variability in TfR than did ferritin. Among infected infants, the inverse association of EPO to hemoglobin was attenuated during early infancy, but significant at 6 months. Similar to HIV-negative infants, EPO was significantly positively associated with TfR throughout the first 6 months of life. However, the inverse association between TfR and ferritin observed among HIV-negative infants at 6 months was not observed among infected infants. Between birth and 6 months, mean serum ferritin concentration declined sharply (by ~90%) in all three groups of babies, but was significantly higher among HIV-positive compared to HIV-negative babies at all time points.

Conclusion

HIV strongly increases anemia risk and confounds interpretation of hematologic indicators in infants. Among HIV-infected infants, the EPO response to anemia is attenuated near the time of infection in the first weeks of life, but normalizes by 6 months.
Chocolate and Prevention of Cardiovascular Disease: A Systematic Review
Authors: Ding Eric L , Hutfless Susan M , Ding Xin , Girotra Saket
Published: January 2006

Background

Consumption of chocolate has been often hypothesized to reduce the risk of cardiovascular disease (CVD) due to chocolate's high levels of stearic acid and antioxidant flavonoids. However, debate still lingers regarding the true long term beneficial cardiovascular effects of chocolate overall.

Methods

We reviewed English-language MEDLINE publications from 1966 through January 2005 for experimental, observational, and clinical studies of relations between cocoa, cacao, chocolate, stearic acid, flavonoids (including flavonols, flavanols, catechins, epicatechins, and procynadins) and the risk of cardiovascular disease (coronary heart disease (CHD), stroke). A total of 136 publications were selected based on relevance, and quality of design and methods. An updated meta-analysis of flavonoid intake and CHD mortality was also conducted.

Results

The body of short-term randomized feeding trials suggests cocoa and chocolate may exert beneficial effects on cardiovascular risk via effects on lowering blood pressure, anti-inflammation, anti-platelet function, higher HDL, decreased LDL oxidation. Additionally, a large body of trials of stearic acid suggests it is indeed cholesterol-neutral. However, epidemiologic studies of serum and dietary stearic acid are inconclusive due to many methodologic limitations. Meanwhile, the large body of prospective studies of flavonoids suggests the flavonoid content of chocolate may reduce risk of cardiovascular mortality. Our updated meta-analysis indicates that intake of flavonoids may lower risk of CHD mortality, RR = 0.81 (95% CI: 0.71–0.92) comparing highest and lowest tertiles.

Conclusion

Multiple lines of evidence from laboratory experiments and randomized trials suggest stearic acid may be neutral, while flavonoids are likely protective against CHD mortality. The highest priority now is to conduct larger randomized trials to definitively investigate the impact of chocolate consumption on long-term cardiovascular outcomes.
What works in alcohol use disorders?
Authors: Luty Jason
Published: January 2006

Treatment of alcohol use disorders typically involves a combination of pharmacotherapy and psychosocial interventions. About one-quarter of people with alcohol dependence (‘alcoholics’) who seek treatment remain abstinent over 1 year. Research has consistently shown that less intensive, community treatment (particularly brief interventions) is just as effective as intense, residential treatment. Many psychosocial treatments are probably equally effective. Techniques for medically assisted detoxification are widespread and effective. More recent evidence provides some support for the use of drugs such as acamprosate to prevent relapse in the medium to long term.
Amyotrophic Lateral Sclerosis and Primary Lateral Sclerosis: The Role of Diffusion Tensor Imaging and Other Advanced MR‐Based Techniques as Objective Upper Motor Neuron Markers
Authors: WANG SUMEI , MELHEM ELIAS R.
Published: January 2006

Amyotrophic lateral sclerosis (ALS), also called Lou Gehrig's disease, is a motor neuron disease characterized by progressive degeneration of upper motor neuron (UMN) and lower motor neuron (LMN), while primary lateral sclerosis (PLS) is defined by pure UMN involvement. A reliable objective marker of UMN involvement is critical for the early diagnosis and monitoring of disease progression in patients with ALS and PLS. Diffusion tensor imaging (DTI), magnetization transfer imaging (MTI), and magnetic resonance spectroscopy (MRS), which provide insight into the pathophysiological process of ALS and PLS, show great promise in this regard. Further investigation is needed to determine and to compare the utility of various neuroimaging markers.
Diffusion Tensor Tractography of the Motor White Matter Tracts in Man: Current Controversies and Future Directions
Authors: HOLODNY ANDREI I. , WATTS RICHARD , KORNEINKO VALERI N. , PRONIN IGOR N. , ZHUKOVSKIY MIKHAIL E. , GOR DEVANG M. , ULUG AZIZ
Published: January 2006

The anatomy of the brain is extremely complex, and certain, even large structures, such as the corticospinal tract (CST), remain poorly understood. Diffusion tractography provides an opportunity to explore the white matter tracts in a fundamentally new way. In the current paper, we show how this technique has already added to our understanding of the anatomy of the CST. We also explore the future projects involving diffusion tractography of the motor white matter tracts that will advance this method and further our understanding of brain anatomy.
Brain/Language Relationships Identified with Diffusion and Perfusion MRI: Clinical Applications in Neurology and Neurosurgery
Authors: HILLIS ARGYE E.
Published: January 2006

Diffusion and perfusion MRI have contributed to stroke management by identifying patients with tissue “at risk” for further damage in acute stroke. However, the potential usefulness of these imaging modalities, along with diffusion tensor imaging, can be expanded by using these imaging techniques with concurrent assessment of language and other cognitive skills to identify the specific cognitive deficits that are associated with diffusion and perfusion abnormalities in particular brain regions. This paper illustrates how this combined behavioral and imaging methodology can yield information that is useful for predicting specific positive effects of intervention to restore blood flow in hypoperfused regions of brain identified with perfusion MRI, and for predicting negative effects of resection of particular brain regions or fiber bundles. Such data allow decisions about neurological and neurosurgical interventions to be based on specific risks and benefits in terms of functional consequences.
Recognition of Chromosomal DNA in Human Cells by Peptide Nucleic Acids and Small Duplex RNAs
Authors: COREY DAVID R.
Published: January 2006

Inhibition of translation by duplex RNA (siRNA) complementary to mRNA is a powerful approach to silencing genes in mammalian cells and RNA interference (RNAi) is an important natural biological mechanism for controlling gene expression. Anti‐mRNA duplexes are widely used for laboratory studies, target validation, and therapeutic development. Endogenously expressed duplex RNAs (microRNAs, miRNAs) have been shown to target mRNA and be natural regulators of expression. Recently, we have shown that peptide nucleic acids (PNAs) or duplex antigene RNAs (agRNAs) that target DNA sequences can also inhibit gene transcription. These findings extend gene silencing to targets within chromosomal DNA.
Therapeutic Potential of Oligonucleotides Expressing Immunosuppressive TTAGGG Motifs
Authors: KLINMAN DENNIS M. , GURSEL IHSAN , KLASCHIK SVEN , DONG LI , CURRIE DEBBIE , SHIROTA HIDEKAZU
Published: January 2006

Synthetic oligodeoxynucleotides (ODNs) expressing immunosuppressive TTAGGG motifs downregulate the production of proinflammatory and Th1 cytokines. The ability of these “suppressive ODNs” to slow or prevent the development of diseases characterized by over‐exuberant immune stimulation was examined. Suppressive ODNs significantly reduced disease severity in murine models of arthritis, lupus, and LPS‐induced toxic shock. These beneficial effects were accompanied by a significant reduction in serum autoantibody and cytokine levels. Underlying these protective effects was the ability of suppressive ODNs to bind to and prevent the phosphorylation of STAT1 and STAT4, thereby blocking the signaling cascade central to the initiation and/or perpetuation of these disease states. These findings suggest that suppressive ODNs might find use in the treatment of acute and chronic diseases characterized by excessive immune stimulation.
Stability Regulation of mRNA and the Control of Gene Expression
Authors: CHEADLE CHRIS , FAN JINSHUI , CHO‐CHUNG YOON S. , WERNER THOMAS , RAY JILL , DO LANA , GOROSPE MYRIAM , BECKER KEVIN G.
Published: January 2006

Microarray technology has become highly valuable for identifying complex global changes in gene expression patterns. Standard techniques measure changes in total cellular poly(A) mRNA levels. The assumption that changes in gene expression as measured by these techniques are directly and well correlated with changes in rates of new gene synthesis form the basis of attempts to connect coordinated changes in gene expression with shared transcription regulatory elements. Yet systematic attempts at this approach remain difficult to demonstrate convincingly. One reason for this difficulty may result from the intricate convergence of both transcriptional and mRNA turnover events which, together, directly influence steady‐state mRNA levels. Recent technical advances have led to the successful scale‐up and application of nuclear run‐on procedures directly to microarrays. This development has allowed a gene‐by‐gene comparison between new gene synthesis in the nucleus and measured changes in total cellular polyA mRNA. Results from these studies have begun to challenge the strict interpretation of changes in gene expression measured by conventional microarrays as being closely correlated with changes in mRNA transcription rate, but rather they tend to support the significant expansion of the role played by changes in mRNA stability regulation to standard analyses of gene expression. Gene expression profiles obtained from both polyA mRNA (whole‐cell) and nuclear run‐on (newly transcribed) RNA across a time course of one hour following the activation of human Jurkat T cells with PMA plus ionomycin revealed that regulation of mRNA stability may account for as much as 50% of all measurements of changes in total cellular polyA mRNA in this system. Stability regulation was inferred by the absence of corresponding regulation of nuclear gene transcription activity for groups of genes strongly regulated at the whole cell level and which were also resistant to inhibition by Actinomycin D pre‐treatment. Consistent patterns across the time course were observed for both transcribed and stability‐regulated genes. It is proposed that the regulation of mRNA stability in response to external stimuli contributes significantly to observed changes in gene expression as measured by high throughput systems.
Differential leg function in a sprawled-posture quadrupedal trotter
Authors: Chen J. J. , Peattie A. M. , Autumn K. , Full R. J.
Published: January 2006

Legs of sprawled-posture, quadrupedal trotting geckos (Hemidactylus garnotii) each functioned differently during constant average-speed locomotion. The center of mass decelerated in the first half of a step and accelerated in the second half, as if geckos were bouncing in fore–aft and side-to-side directions. Forelegs decelerated the center of mass only in the fore–aft direction. Hindlegs provided all the acceleration in the latter half of the step. Lateral ground reaction forces were always directed toward the midline and exceeded the magnitude of fore–aft forces. The differential leg function of sprawled-posture geckos resembled sprawled-posture hexapods more than upright-posture quadrupeds. The pattern of leg ground reaction forces observed may provide passive, dynamic stability while minimizing joint moments, yet allow high maneuverability. Integrating limb dynamics with whole body dynamics is required to resolve the trade-offs,if any, that result from stable sprawled-posture running with differential leg function.
Iridescent plumage in satin bowerbirds: structure, mechanisms and nanostructural predictors of individual variation in colour
Authors: Doucet Stéphanie M. , Shawkey Matthew D. , Hill Geoffrey E. , Montgomerie Robert
Published: January 2006

Iridescence is produced by coherent scattering of light waves from alternating layers of materials of different refractive indices. In birds,iridescent colours are produced by feather barbules when light is scattered from alternating layers of keratin, melanin and air. The structure and organization of these layers, and hence the appearance of bird species with different types of plumage iridescence, varies extensively. One principal distinction between different types of iridescent colours is whether they are produced by a single pair of layers or by multiple pairs of layers. Multi-layer iridescence, such as that displayed by hummingbirds, has been relatively well characterized, but single-layer iridescence has only recently been modeled successfully. Here we use electron microscopy, spectrometry and thin-film optical modeling to investigate the glossy, ultraviolet-blue iridescent plumage colouration of adult male satin bowerbirds Ptilonorhynchus violaceus minor. The flattened barbules of adult males are composed of a superficial keratin layer overlying a melanin layer that is several granules thick. A thin-film model based on the thickness of the keratin layer and its two associated interfaces (air/keratin and keratin/melanin) generates predicted reflectance spectra that closely match measured spectra. In addition, hues predicted from this model are positively correlated with measured hues. As predicted from our thin-film model, measured hues shifted to shorter wavelengths at increasing angles of incidence and reflectance. Moreover, we found that individual variation in barbule nanostructure can predict measured variation in both hue and UV-chroma. Thus,we have characterized the microstructure of satin bowerbird barbules,uncovered the mechanisms responsible for producing ultraviolet iridescence in these barbules, and provided the first evidence of a nanostructural basis for individual variation in iridescent plumage colour.
Influence of the behavioural context on the optocollic reflex (OCR) in pigeons (Columba livia)
Authors: Maurice Monique , Gioanni Henri , Abourachid Anick
Published: January 2006

We investigated the effects of several behavioural conditions on the properties of the horizontal optocollic reflex (OCR) in pigeons. The head reflex was triggered by rotating the visual surroundings at different velocities (stimuli steps of 30-300 deg. s-1) and the characteristics of the slow and fast phases of the OCR were analysed during,(i) the `resting condition', in which animals were hung in a harness, (ii) the`standing condition', in which animals were freely standing, (iii) the`walking condition', in which animals were walking on a treadmill at different velocities, and (iv) the `flying condition', in which animals were hung in a harness and subjected to a frontal air-stream, provoking a flying posture.

In the `resting' condition, irregularities were observed in the amplitude of nystagmic beats, in the beating field and in the slow phase velocity (SPV)of the OCR. These irregularities diminished progressively when the behavioural condition changed from `standing' to `walking', and disappeared in the`flying' condition. Correlatively, the working range of the OCR (evaluated by its gain at the plateau of SPV) was progressively extended toward higher stimulation velocities.

The velocity of the fast phases of the OCR (measured for all the conditions except the `walking condition') also increased in correlation with the SPV. The walking speed did not influence the OCR in the treadmill velocity range of 0.20-0.40 m s-1. The presence of a frontal airstream in the`standing condition' did not change the OCR properties. This fact (and other observations discussed in the paper) suggests that the adaptation of the OCR to the behavioural context is mediated by internal signals generated by each behavioural condition.
Miniature Synaptic Events Elicited by Presynaptic Ca2+ Rise Are Selectively Suppressed by Cannabinoid Receptor Activation in Cerebellar Purkinje Cells
Authors: Yamasaki Miwako , Hashimoto Kouichi , Kano Masanobu
Published: January 2006

Activation of cannabinoid receptors suppresses neurotransmitter release in various brain regions. In cerebellar Purkinje cells (PCs), cannabinoid agonists suppress both EPSC and IPSC evoked by stimulating the corresponding inputs. However, cannabinoid agonists suppress miniature IPSC (mIPSC) but not miniature EPSC (mEPSC) at normal external Ca2+concentration ([Ca2+]o). Therefore, cannabinoid agonists are thought to suppress release machinery for IPSCs but not that for EPSCs. Here we investigated the possible cause of this difference and found that cannabinoid agonists selectively suppressed Ca2+-enhanced miniature events. A cannabinoid agonist, WIN55,212-2 (5 μm), did not affect mEPSC frequency with 2 mmextracellular Ca2+(Ca2+o). However, WIN55,212-2 became effective when mEPSC frequency was enhanced by elevation of presynaptic Ca2+level by perfusion with 5 mmCa2+oor bath application of A23187, a Ca2+ionophore. In contrast, WIN55,212-2 suppressed mIPSC frequency with 2 mmCa2+o, but it became ineffective when the presynaptic Ca2+level was lowered by perfusion with a Ca2+-free solution containing BAPTA-AM. Experiments with systematic [Ca2+]ochanges revealed that mIPSC but not mEPSC regularly involved events elicited by presynaptic Ca2+rise with 2 mmCa2+o. Importantly, Ca2+-enhancement of mEPSC and mIPSC was not attributable to activation of voltage-dependent Ca2+channels. Activation of GABABreceptor or group III metabotropic glutamate receptor, which couple to Gi/o-protein, also preferentially suppressed Ca2+-enhanced miniature events in PCs. These results suggest that the occurrence of Ca2+-enhanced miniature events at normal [Ca2+]odetermines the sensitivity to the presynaptic depression mediated by cannabinoid receptors and other Gi/o-coupled receptors in PCs.
Myelin Impairs CNS Remyelination by Inhibiting Oligodendrocyte Precursor Cell Differentiation
Authors: Kotter Mark R. , Li Wen-Wu , Zhao Chao , Franklin Robin J. M.
Published: January 2006

Demyelination in the adult CNS can be followed by extensive repair. However, in multiple sclerosis, the differentiation of oligodendrocyte lineage cells present in demyelinated lesions is often inhibited by unknown factors. In this study, we test whether myelin debris, a feature of demyelinated lesions and anin vitroinhibitor of oligodendrocyte precursor differentiation, affects remyelination efficiency. Focal demyelinating lesions were created in the adult rat brainstem, and the naturally generated myelin debris was augmented by the addition of purified myelin. After quantification of myelin basic protein mRNA expression from lesion material obtained by laser capture microdissection and supported by histological data, we found a significant impairment of remyelination, attributable to an arrest of the differentiation and not the recruitment of oligodendrocyte precursor cells. These data identify myelin as an inhibitor of remyelination as well as its well documented inhibition of axon regeneration.
The Role of the Amygdala and Olfaction in Unconditioned Fear in Developing Rats
Authors: Chen Sean W. C. , Shemyakin Alexei , Wiedenmayer Christoph P.
Published: January 2006

Early in ontogeny, young rats must be able to detect dangerous stimuli and to exhibit appropriate defensive behaviors. Different nuclei of the amygdala mediate unconditioned and conditioned fear responses to threat in adult rats. The aim of this study was to determine the role of the amygdala in unlearned fear behavior in young rats. When exposed to an unfamiliar adult male rat, preweaning rat pups freeze, with peak levels on postnatal day 14 and declining levels on day 18. Pups were made anosmic to block olfactory input to the amygdala, and amygdala activation was assessed by quantifying the neuronal marker c-fos. Anosmic pups did not freeze in the presence of the male rat and had decreased c-fosexpression in the medial amygdala on day 14 and in the medial and lateral amygdala on day 18. However, the decrease in freezing between days 14 and 18 was not associated with a decrease in c-fosexpression in the medial amygdala. The medial and lateral amygdala were then inactivated by local muscimol infusion on day 14. Muscimol infusion into the medial amygdala decreased freezing to the male rat but not to a loud noise, whereas infusion into the lateral amygdala blocked freezing to a loud noise but not to the male. These findings indicate that different nuclei of the amygdala process sensory information of different modalities, mediate unconditioned freezing, and may be involved in developmental changes in the fear response in young rats.
Cytoarchitecture of Pneumotaxic Integration of Respiratory and Nonrespiratory Information in the Rat
Authors: Song Gang , Yu Yunguo , Poon Chi-Sang
Published: January 2006

The “pneumotaxic center” in the Kölliker-Fuse and medial parabrachial nuclei of dorsolateral pons (dl-pons) plays an important role in respiratory phase switching, modulation of respiratory reflex, and rhythmogenesis. Recent electrophysiological and neural tracing data implicate additional pneumotaxic nuclei in (and a broader role for) the dl-pons in integrating respiratory and nonrespiratory information. Here, we examined the cytoarchitecture of the greater pneumotaxic center and its integrating function by using combined extracellular recording and juxtacellular labeling of unit respiratory rhythmic neurons in dl-pons in urethane-anesthetized, vagotomized, paralyzed, and servo-ventilated adult Sprague Dawley rats. Perievent histogram analysis identified four major types of neuronal discharge patterns: inspiratory, expiratory (with three subdivisions), inspiratory–expiratory, and expiratory–inspiratory phase spanning, sometimes with mild tonic background activity. Most recorded neurons were localized in the Kölliker-Fuse and medial parabrachial nuclei, but some were also found in lateral parabrachial nucleus, intertrigeminal nucleus, principal trigeminal sensory nucleus, and supratrigeminal nucleus. The majority of labeled neurons had large and spatially extended dendritic trees that spanned several of these dl-pons subnuclei, often with terminal dendrites ending in the ventral spinocerebellar tract. The distal sections of the primary and higher-order dendrites exhibited rich varicosities, sometimes with dendritic spines. Axons of some labeled neurons were traced all the way to the ventrolateral pons (vl-pons). These findings extend and generalize the classical definition of the pneumotaxic center to include extensive somatic–axonal–dendritic integration of complex descending and ascending respiratory information as well as nociceptive and possibly musculoskeletal and trigeminal information in multiple dl-pons and vl-pons structures in the rat.
L-Tyrosine Contributes to (+)-3,4-Methylenedioxymethamphetamine-Induced Serotonin Depletions
Authors: Breier Joseph M. , Bankson Michael G. , Yamamoto Bryan K.
Published: January 2006

The specific mechanisms underlying (+)-3,4-methylenedioxymethamphetamine (MDMA)-induced damage to 5-HT terminals are unknown. Despite the hypothesized role for dopamine (DA) and DA-derived free radicals in mediating this damage, it remains unclear why MDMA produces long-term depletions of 5-HT in brain regions that are sparsely innervated by DA neurons. We hypothesized that the precursor to DA biosynthesis, tyrosine, mediates MDMA-induced 5-HT depletions. Extracellular tyrosine concentrations increased fivefold in striatum and 2.5-fold in hippocampus during the administration of neurotoxic doses of MDMA.In vitroresults show thatl-tyrosine can be hydroxylated nonenzymatically to the DA precursorl-3,4-dihydroxyphenylalanine (DOPA) under pro-oxidant conditions. The local infusion ofl-tyrosine into the striatum or hippocampus during MDMA administration potentiated the acute increase in extracellular DA and the long-term depletion of 5-HT after MDMA. Coinfusion of the aromatic amino acid decarboxylase (AADC) inhibitorm-hydroxybenzylhydrazine attenuated these effects in hippocampus and decreased basal extracellular DA in the striatum. In contrast, the reverse dialysis of the tyrosine hydroxylase inhibitor α-methyl-p-tyrosine into the hippocampus did not affect MDMA-induced increases in extracellular DA or the long-term depletion in 5-HT. These results show that MDMA increases the concentration of tyrosine in the brain to cause a long-term depletion of 5-HT via the nonenzymatic, tyrosine hydroxylase-independent, hydroxylation of tyrosine to DOPA and subsequently to DA via AADC. Overall, the findings suggest that MDMA depletes 5-HT by increasing tyrosine and its eventual conversion to DA within 5-HT terminals.
Imaging Response Inhibition in a Stop-Signal Task: Neural Correlates Independent of Signal Monitoring and Post-Response Processing
Authors: Ray Li Chiang-shan , Huang Cong , Constable R. Todd , Sinha Rajita
Published: January 2006

Execution of higher cortical functions requires inhibitory control to restrain habitual responses and meet changing task demands. We used functional magnetic resonance imaging to show the neural correlates of response inhibition during a stop-signal task. The task has a frequent “go” stimulus to set up a pre-potent response tendency and a less frequent “stop” signal for subjects to withhold their response. We contrasted brain activation between successful and failed inhibition for individual subjects and compared groups of subjects with short and long stop-signal reaction times. The two groups of subjects did not differ in their inhibition failure rates or the extent of signal monitoring, error monitoring, or task-associated frustration ratings. The results showed that short stop-signal reaction time or more efficient response inhibition was associated with greater activation in the superior medial and precentral frontal cortices. Moreover, activation of these inhibitory motor areas correlated negatively with stop-signal reaction time. These brain regions may represent the neural substrata of response inhibition independent of other cognitive and affective functions.
Tumor Necrosis Factor α But Not Interleukin 1β Mediates Neuroprotection in Response to Acute Nitric Oxide Excitotoxicity
Authors: Turrin Nicolas P. , Rivest Serge
Published: January 2006

Neurodegenerative processes in the brain are accompanied by activation of innate immunity, which involves the release of proinflammatory cytokines by microglia and infiltrating macrophages. The beneficial or detrimental roles of these cytokines, including interleukin 1β (IL-1β) and tumor necrosis factor α (TNF-α), remain to be clarified. These cytokines have numerous overlapping activities that make it difficult to interpret data generated by mice that have a mutation in the gene encoding either TNF-α or IL-1β. To remediate the problem, we generated a mouse that bears a mutation in both genes and exposed them to an acute neurotoxic insult. Intracerebral infusion with the nitric oxide donor sodium nitroprusside (SNP) caused neurodegeneration and demyelination that were markedly increased in the brain of TNF-α- and IL-1β/TNF-α-deficient mice compared with IL-1β-deficient and wild-type mice. Surprisingly, TNF and double mutants exhibited an early (6 h after SNP injections) blunted microglial activation followed by an exaggerated response later on (4 d later). No differences were found in the brain of the IL-1β knock-out and wild-type groups. This suggests a crucial role for TNF-α in mediating microglial reactivity to acute injury. An immediate response clearly helps eliminate cell debris, restrict subsequent damages, and restore homeostasis. These findings may have direct implications for the use anti-inflammatory drugs in acute neurodegenerative and demyelinating disorders.
Early 15th-Century Pairings of the Sanctus and Agnus Dei, and the Case of the Composer “Bloym”
Authors: WRIGHT PETER
Published: January 2006

Self-contained pairings of the polyphonic Sanctus and Agnus Dei (as distinct from the Gloria and Credo) appear to have been something of a rarity in the early 15th century, both on the Continent and in England. In their catalogue of 15th-century English liturgical music, Gareth Curtis and Andrew Wathey list just five firm Sanctus-Agnus pairs for the period ca. 1400–ca. 1440. Yet examination of these alleged pairs suggests that the status of all but one of them is in some degree open to question. Curtis and Wathey's catalogue also includes a number of movements that have been paired either by 15th-century scribes or by modern commentators but that have so far failed to convince. Among them is a group of eight closely related movements contained in a layer of the two oldest Trent Codices (MSS 87 and 92), which comprises four possible pairs. Investigation suggests that all eight movements are probably the work of the same composer, “Bloym,” whose name heads one of the Sanctus settings; that in the process of transmission a number of the movements became wrongly associated; and that by realigning them new and more plausible pairings can be established. The establishment of connections between one of these pairings and a Credo attributed to Bloym in the same Trent layer raises the possibility that all three movements may have been conceived in conjunction with one another, and may therefore form a partial or incomplete cycle.
Bacterial Meningitis Among Children With Cochlear Implants Beyond 24 Months After Implantation
Authors: Biernath Krista R. , Reefhuis Jennita , Whitney Cynthia G. , Mann Eric A. , Costa Pamela , Eichwald John , Boyle Coleen
Published: January 2006

Background. More than 11000 children in the United States with severe-to-profound hearing loss have cochlear implants. A 2002 investigation involving pediatric cochlear implant recipients identified meningitis episodes from January 1, 1997, through September 15, 2002. The incidence of pneumococcal meningitis in the cohort was 138.2 cases per 100000 person-years, >30 times higher than that for children in the general US population. Children with implants with positioners were at higher risk than children with other implant models. This higher risk of bacterial meningitis continued for up to 24 months after implantation.

Objective. To evaluate additional reported cases to determine whether the increased rate of bacterial meningitis among children with cochlear implants extended beyond 24 months after implantation.

Methods. Our study population consisted of the cohort of children identified through the 2002 investigation; it included 4265 children who received cochlear implants in the United States between January 1, 1997, and August 6, 2002, and who were <6 years of age at the time of implantation. We calculated updated incidence rates and incidence according to time since implantation.

Results. We identified 12 new episodes of meningitis for 12 children. Eleven of the children had implants with positioners; 2 children died. Six episodes occurred >24 months after implantation. When cases identified in the 2002 and 2004 investigations were combined, the incidence rate of ≥24-months postimplantation bacterial meningitis among children with positioners was 450 cases per 100000 person-years, compared with no cases among children without positioners.

Conclusions. Our updated findings support continued monitoring and prompt treatment of bacterial infections by health care providers and parents of children with cochlear implants. This vigilance remains important beyond 2 years after implantation, particularly among children with positioners. The vaccination recommendations for all children with implants, with and without positioners, and all potential recipients of implants continue to apply.
Compressive properties of lotus-type porous stainless steel
Authors: Ide T. , Tane M. , Ikeda T. , Hyun S.K. , Nakajima H.
Published: January 2006

Lotus-type porous stainless steel (SUS304L), possessing cylindrical pores aligned in one direction, was fabricated by means of a continuous zone melting technique undera pressurized hydrogen/helium atmosphere. Compression tests were carried out on the resultant lotus stainless steel not only in the directions parallel and perpendicular tothe elongated-pore direction but also in other directions to reveal its anisotropic compressive behavior. The macroscopic deformation modes depend on porosity and the angle between the elongated-pore direction and compression direction, which is a unique characteristic resulting from its anisotropic porous structure. The yield stress in the pore direction decreases almost linearly with increasing porosity, while that in the perpendicular direction decreases more rapidly. The yield stress in the direction of θ from the elongated-pore direction decreases monotonically with increase in θ. The yield behavior of lotus stainless steel was described using micromechanical mean-field theory.
Domain size change of spinodal phase separation structure in the sol-gel derived TiO2 thin film
Authors: Mori Ryohei , Takahashi Masahide , Yoko Toshinobu
Published: January 2006

TiO2 thin films were prepared with a spinodal phase separation structure ranging from hundreds of nanometers to micrometers in size by the sol-gel dip-coating method from a titanium tetraisopropoxide solution containing polyoxyethylene (20) nonylphenyl ether (NPE-20). It was possible to change the titania domain size of the spinodal phase separation structure by selecting alcohol as the solvent because the polycondensation and the phase separation are severely influenced by its evaporation rate from the surface of the coated film. It was also observed that the titania domains became larger in size as the film thickness increased in the bottom area of the substrate when the dip-coating method was applied, while uniformly sized titania domains were possibly formed by a spin-coating method. Furthermore, the contrast between the TiO2 phase and the air phase was not sharp when the titania domain size was smaller than several hundreds of nanometers. It was possible to prepare TiO2-air interconnective films with the spinodal phase separation structure 200–300 nm in domain size by subsequent HF etching. In addition, combining spinodal phase separation structure (SPSS) TiO2 thin film with different skeleton size has the potential to create TiO2 thin film with high photo-electron conversion efficiency due to its particular structure, higher surface area, and lack of bottleneck for electron transfer.
Plasmon resonance absorption in sulfide-coated gold nanorods
Authors: Chatterjee K. , Basu S. , Chakravorty D.
Published: January 2006

Gold nanorods 100 nm in diameter were grown within polycarbonate membranes as templates by the electrodeposition technique. A low-temperature sulfidation process was used to make gold sulfide nanoshells around the nanorods with a thickness of ∼7 nm. Optical absorption measurements were carried out on sulfide-coated gold nanorods obtained by dissolving the polycarbonate membrane. Several peaks were observed. These were analyzed on the basis of longitudinal and transverse modes of gold nanorods, the core–shell structure of gold–gold sulfide, and the presence of nanoparticles of gold. Theoretical analysis was carried out using a modified Mie scattering formalism. Satisfactory agreement between experimental results and theoretical fits were obtained.
Energetics of cubic Si3N4
Authors: Zhang Yahong , Navrotsky Alexandra , Sekine Toshimori
Published: January 2006

High-temperature oxide melt drop solution calorimetry was used to study the energetics of formation of cubic silicon nitride prepared at high pressure. The standard enthalpy of formation of c-Si3N4is −776.3 ± 9.5 kJ/mol. The calorimetric measurement of Si3N4in 3Na2O·4MoO3solvent was validated by comparing the enthalpy of formation for β–Si3N4with previous work using alkali borate solvent. The enthalpy of transformation from β– to c-Si3N4is 80.2 ± 9.6 kJ/mol. This value appears consistent with the observed synthesis conditions, which do not represent reversed equilibrium reactions.
Neuropeptide W is present in antral G cells of rat, mouse, and human stomach
Authors: Mondal M S , Yamaguchi H , Date Y , Toshinai K , Kawagoe T , Tsuruta T , Kageyama H , Kawamura Y , Shioda S , Shimomura Y , Mori M , Nakazato M
Published: January 2006

Neuropeptide W (NPW) is a 30-amino-acid peptide initially isolated from the porcine hypothalamus as an endogenous ligand for the G protein-coupled receptors GPR7 and GPR8. An intracerebroventricular administration of NPW increased serum prolactin and corticosterone concentrations, decreased dark-phase feeding, raised energy expenditure, and lowered body weight. Peripherally, GPR7 receptors are abundantly expressed throughout the gastrointestinal tract; the presence of NPW in the gastrointestinal endocrine system, however, remains unstudied. Using monoclonal and polyclonal antibodies raised against rat NPW, we studied the localization of NPW in the rat, mouse, and human stomach by light and electron microscopy. NPW-immunoreactive cells were identified within the gastric antral glands in all three species. Double immunohistochemistry and electron-microscopic immunohistochemistry studies in rats demonstrated that NPW is present in antral gastrin (G) cells. NPW immunoreactivity localized to round, intermediate-to-high-density granules in G cells. NPW-immunoreactive cells accounted for 90% chromagranin A- and 85% gastrin-immunoreactive endocrine cells in the rat gastric antral glands. Using reversed-phase HPLC coupled with enzyme immunoassays specific for NPW, we detected NPW30 and its C-terminally truncated form, NPW23, in the gastric mucosa. Plasma NPW concentration of the gastric antrum was significantly higher than that of the systemic vein, suggesting that circulating NPW is derived from the stomach. Plasma NPW concentration of the gastric antrum decreased significantly after 15-h fast and increased after refeeding. This is the first report to clarify the presence of NPW peptide in the stomachs of rats, mice, and humans. In conclusion, NPW is produced in gastric antral G cells; our findings will provide clues to additional mechanisms of the regulation of gastric function by this novel brain/gut peptide.
Gene expression of glucose transporter (GLUT) 1, 3 and 4 in bovine follicle and corpus luteum
Authors: Nishimoto H , Matsutani R , Yamamoto S , Takahashi T , Hayashi K-G , Miyamoto A , Hamano S , Tetsuka M
Published: January 2006

Glucose is the main energy substrate in the bovine ovary, and a sufficient supply of it is necessary to sustain the ovarian activity. Glucose cannot permeate the plasma membrane, and its uptake is mediated by a number of glucose transporters (GLUT). In the present study, we investigated the gene expression of GLUT1, 3 and 4 in the bovine follicle and corpus luteum (CL). Ovaries were obtained from Holstein × Japanese Black F1 heifers. Granulosa cells and theca interna layers were harvested from follicles classified into five categories by their physiologic status: follicular size (≥ 8.5 mm: dominant; < 8.5 mm: subordinate), ratio of estradiol (E2) to progesterone in follicular fluid (≥ 1: E2 active;<1: E2 inactive), and stage of estrous cycle (luteal phase, follicular phase). CL were also classified by the stage of estrous cycle. Expression levels of GLUT1, 3 and 4 mRNA were quantified by a real-time PCR. The mRNA for GLUT1 and 3 were detected in the bovine follicle and CL at comparable levels to those in classic GLUT-expressing organs such as brain and heart. Much lower but appreciable levels of GLUT4 were also detected in these tissues. The gene expression of these GLUT showed tissue- and stage-specific patterns. Despite considerable differences in physiologic conditions, similar levels of GLUT1, 3 and 4 mRNA were expressed in subordinate follicles as well as dominant E2-active follicles in both luteal and follicular phases, whereas a notable increase in the gene expression of these GLUT was observed in dominant E2-inactive follicles undergoing the atretic process. In these follicles, highly significant negative correlations were observed between the concentrations of glucose in follicular fluid and the levels of GLUT1 and 3 mRNA in granulosa cells, implying that the local glucose environment affects glucose uptake of follicles. These results indicate that GLUT1 and 3 act as major transporters of glucose while GLUT4 may play a supporting role in the bovine follicle and CL.
Persistence of Glyphosate‐Resistant Canola in Western Canadian Cropping Systems
Authors: Harker K. N. , Clayton G. W. , Blackshaw R. E. , O'Donovan J. T. , Johnson E. N. , Gan Y. , Holm F. A. , Sapsford K. L. , Irvine R. B. , Van Acker R. C.
Published: January 2006

Canola (Brassica napus L.) is the most important oilseed crop in western Canada. Its prevalence across the Canadian Prairies influences the occurrence and impact of canola volunteers as weeds. Here we determined the persistence of canola seed in cropping systems so effective volunteer management strategies can be developed. In mid‐ to late‐October of 2000, approximately 770 seeds m−2 of glyphosate [N‐(phosphonomethyl)glycine]–resistant (GR) canola were scattered on plot areas at seven western Canadian sites. From 2001 to 2003 the plots were seeded to a wheat (Triticum aestivum L.)–field pea (Pisum sativum L.)–barley (Hordeum vulgare L.) rotation or a fallow–field pea–fallow rotation in five different seeding systems involving seeding dates and soil disturbance levels, and monitored four times each year for canola plant density. Crop seeding date did not consistently influence volunteer canola density. With some exceptions, higher levels of soil disturbance led to higher volunteer canola densities. The vast majority of canola seedlings were recruited in the year following seed dispersal (2001). Across all locations, rotations, and seeding systems, and averaged over preplanting (PREP) and in‐crop prespray (PRES) intervals, canola densities were 6.2, 0.7, and 0.0 plants m−2 in 2001, 2002, and 2003, respectively. Canola volunteers were usually most abundant at PREP and PRES intervals; total recruitment at those intervals averaged across all seeding systems in the continuous cropping rotation was 3% (25 plants m−2). Preventing seed production in new canola volunteers in 2001 reduced canola densities in subsequent years (2002 and 2003) below those required to mitigate weed–crop competition influences in most crops.
Spatiotemporal Evolution of Soil pH and Zinc after the Aznalcóllar Mine Spill
Authors: Vanderlinden Karl , Polo Maria J. , Ordóñez Rafaela , Giráldez Juan V.
Published: January 2006

The residual pollution after the Aznalcóllar (southwestern Spain) pyrite mine spill is still a threat due to the continuing oxidation of sulfuric minerals. The objective of this paper was to analyze the combined effect of pyrite oxidation, sugar beet foam applications, and meteorological conditions on the spatiotemporal evolution of the pH and EDTA‐extractable Zn concentration, using non co‐located data from 11 sampling dates between June 1999 and March 2002. Median pH values ranged from 4.4 at the beginning of the monitoring period to 7.6 at the end, although values near 2.5 were observed throughout the entire period, despite of two sugar beet foam (SBF) applications. Zinc distributions were positively skewed and median concentrations ranged from 17 to 94 mg kg−1The inverse relationship between pH and Zn became weaker toward the end of the monitoring period as a consequence of the precipitation and posterior dissolution of newly formed minerals from the reaction products of the pyrite oxidation. Normal score maps showed that after the SBF applications only 0.5% of the monitored area was below the pH = 4 threshold, while on other dates up to one‐third of the area remained below this value. The better performance of the second SBF application could be explained in terms of pyrite oxidation pathways and environmental conditions. From this analysis, with data obtained under uncontrolled field conditions, it is concluded that SBF should be applied before or during the wet and cold season to alleviate acidification, caused by the oxidation of pyrite or other sulfuric minerals.