bluuebunny/crossref_metadata_2025_split huggingface dataset:
The role of inhibition in oscillatory wave dynamics in the cortex
Authors: Xiao Ying , Huang Xiao‐ying , Van Wert Stephen , Barreto Ernest , Wu Jian‐young , Gluckman Bruce J. , Schiff Steven J. 
Published: July 2012

AbstractCortical oscillations arise during behavioral and mental tasks, and all temporal oscillations have particular spatial patterns. Studying the mechanisms that generate and modulate the spatiotemporal characteristics of oscillations is important for understanding neural information processing and the signs and symptoms of dynamical diseases of the brain. Nevertheless, it remains unclear how GABAergic inhibition modulates these oscillation dynamics. Using voltage‐sensitive dye imaging, pharmacological methods, and tangentially cut occipital neocortical brain slices (including layers 3–5) of Sprague‐Dawley rat, we found that GABAa disinhibition with bicuculline can progressively simplify oscillation dynamics in the presence of carbachol in a concentration‐dependent manner. Additionally, GABAb disinhibition can further simplify oscillation dynamics after GABAa receptors are blocked. Both GABAa and GABAb disinhibition increase the synchronization of the neural network. Theta frequency (5–15‐Hz) oscillations are reliably generated by using a combination of GABAa and GABAb antagonists alone. These theta oscillations have basic spatiotemporal patterns similar to those generated by carbachol/bicuculline. These results are illustrative of how GABAergic inhibition increases the complexity of patterns of activity and contributes to the regulation of the cortex.
Metabolic adaptations of Pseudomonas aeruginosa during cystic fibrosis chronic lung infections
Authors: Behrends V. , Ryall B. , Zlosnik J. E. A. , Speert D. P. , Bundy J. G. , Williams H. D. 
Published: July 2012

SummaryPseudomonas aeruginosa forms chronic infections in the lungs of cystic fibrosis (CF) patients, and is the leading cause of morbidity and mortality in patients with CF. Understanding how this opportunistic pathogen adapts to the CF lung during chronic infections is important to increase the efficacy of treatment and is likely to increase insight into other long‐term infections. Previous studies of P. aeruginosa adaptation and divergence in CF infections have focused on the genetic level, both identifying characteristic mutations and patterns of gene expression. However, these approaches are not sufficient to fully understand the metabolic changes that occur during long‐term infection, as metabolic regulation is complex and takes place on different biological levels. We used untargeted metabolic profiling (metabolomics) of cell supernatants (exometabolome analysis, or metabolic footprinting) to compare 179 strains, collected over time periods ranging from 4 to 24 years for the individual patients, representing a series of mostly clonal lineages from 18 individual patients. There was clear evidence of metabolic adaptation to the CF lung environment: acetate production was highly significantly negatively associated with length of infection. For amino acids, which are available to the bacterium in the lung environment, the tendency of isolates to evolve more efficient uptake was related to the biosynthetic cost of producing each metabolite; conversely, for the non‐mammalian metabolite trehalose, isolates had significantly reduced tendency to utilize this compound with length of infection. However, as well as adaptation across patients, there was also a striking degree of metabolic variation between the different clonal lineages: in fact, the patient the strains were isolated from was a greater source of variance than length of infection for all metabolites observed. Our data highlight the potential for metabolomic investigation of complex phenotypic adaptations during infection.
Multifactorial risk factor intervention in patients with Type 2 diabetes improves arginine bioavailability ratios
Authors: Tripolt N. J. , Meinitzer A. , Eder M. , Wascher T. C. , Pieber T. R. , Sourij H. 
Published: July 2012

Diabet. Med. 29, e365–e368 (2012)AbstractAim  Endothelial dysfunction is defined by reduced bioavailability of nitric oxide and has been shown to be associated with cardiovascular risk. The global arginine bioavailability ratio and the arginine to ornithine ratio have recently been shown to be associated with cardiovascular outcome in patients with coronary artery disease. The aim of our study was to investigate the impact of a multifactorial risk factor intervention in subjects with Type 2 diabetes on these two potential new cardiovascular surrogate parameters.Methods  In a single‐centre and prospective study, we investigated 41 patients with Type 2 diabetes not reaching treatment targets according to current local diabetes guidelines in two out of three of the following measurements: HbA1c LDL cholesterol 2.6 or blood pressure. Within 3 months, therapy was intensified according to current guidelines aiming to reach the treatment targets. At baseline and 3 months, arginine, ornithine and citrulline were chromatographically determined after pre‐column‐derivatization followed by fluorescent detection, and arginine bioavailability ratios were calculated.Results  Intensified risk factor management significantly improved the global arginine bioavailability ratio (0.33 ± 0.12 at baseline vs. 0.38 ± 0.14 after 3 months; P = 0.018). A significant improvement was only seen in patients with short diabetes duration (< 5 years), whereas in patients with longer diabetes duration improvement did not reach statistical significance.Conclusion  In patients with Type 2 diabetes, intensified risk factor management improves arginine bioavailability ratios. Duration of diabetes seems to be an important factor influencing the capacity of the global arginine bioavailability ratio improvement.
Potential role of non‐insulin adjunct therapy in Type 1 diabetes
Authors: George P. , McCrimmon R. J. 
Published: July 2012

Diabet. Med. 30, 179–188 (2013)AbstractDespite improvements in the pharmacodynamics of injectable insulin and better insulin delivery systems, glucose control remains suboptimal in the majority of individuals with Type 1 diabetes. Profound defects in the physiological processes that normally maintain glucose homeostasis contribute to the difficulty in achieving glycaemic targets. Non‐insulin‐based adjunct treatments offer a potential means of complementing intensive insulin therapy in Type 1 diabetes through addressing some of the physiological disturbances that result from endogenous β‐cell destruction, particularly through preservation of β‐cell mass and prevention of apoptosis, and suppression of α‐cell glucagon release in the postprandial state. The former approach applies most readily to newly diagnosed C‐peptide‐positive Type 1 diabetes, while the latter to established C‐peptide‐negative Type 1 diabetes. This review focuses primarily on the clinical trial data available on the use of non‐insulin‐based therapies in longer‐duration Type 1 diabetes. We conclude that metformin may prove useful in macrovascular disease reduction, while pramlintide, glucagon‐like peptide‐1 agonists, dipeptidyl peptidase‐4 inhibitors and leptin co‐therapies may reduce HbA1c, glucose variability, postprandial glucose excursions and body weight. These early studies are encouraging and offer novel and potentially very effective approaches to the treatment of Type 1 diabetes, but the evidence is largely restricted to small, often uncontrolled trials. As such, these therapies cannot be currently recommended for routine clinical practice. There is a clear need to support large, multi‐centre randomized controlled trials designed to establish whether adjunct insulin therapy has a place in the modern management of Type 1 diabetes.
Are Global Imbalances Sustainable? Shedding Further Light on the Causes of Current Account Reversals
Authors: de Mello Luiz , Padoan Pier Carlo , Rousová Linda 
Published: July 2012

AbstractLarge shifts in countries' external current account positions can be disruptive, often reflecting sudden stops in the flows of external finance and leading to exchange rate and banking crises. As a result, an empirical literature has emerged on the sustainability of, and the determinants of large swings in, current account positions. Further light is shed on this issue by testing for the presence of unit roots in the current account balance‐to‐gross domestic product (GDP) ratios of a large set of mature and emerging‐market economies using a methodology that allows for structural breaks in levels and trends. A chronology is constructed of current account reversals that is consistent with sustainability of external positions and it is used to estimate the factors explaining the likelihood and magnitude of such reversals by utilising a selection model with ordered probit in the selection stage. It is found that most of the factors that explain the probability of reversals, such as trends in capital flows, in the budget balance and in external positions, also influence their magnitude, but there are a few exceptions. For instance, the stance of monetary policy and the magnitude of external imbalances prior to a reversal seem to be more powerful predictors of the probability of reversals than of their magnitude.
Share Repurchase Reasons and the Market Reaction to Actual Share Repurchases: Evidence from Australia
Authors: Akyol Ali C. , Foo Chi Chong 
Published: July 2012

AbstractUsing repurchase reasons provided by Australian companies for their stock repurchase programs, we ask if the market's response is different across repurchase motivations by examining actual daily share repurchases. We find that firms with the undervaluation motive experience a more positive stock price reaction when they report their repurchases to the market. We show that undervaluation motive firms repurchase fewer shares and have a lower program completion rate than other motives firms. During the 1‐year period following the repurchases, undervaluation motive firms do better than their control sample firms whereas other motive firms do not perform better or worse than their control sample firms. Overall, our results suggest that the undervaluation motive is a stronger signal than other repurchase motives, and contrary to the predictions of the standard signaling theories, management statements carry some value for the market. We also present some evidence suggesting that a costly action may not be needed for a signal to be credible.
Development and evolution of the vertebrate primary mouth
Authors: Soukup Vladimír , Horácek Ivan , Cerny Robert 
Published: July 2012

AbstractThe vertebrate oral region represents a key interface between outer and inner environments, and its structural and functional design is among the limiting factors for survival of its owners. Both formation of the respective oral opening (primary mouth) and establishment of the food‐processing apparatus (secondary mouth) require interplay between several embryonic tissues and complex embryonic rearrangements. Although many aspects of the secondary mouth formation, including development of the jaws, teeth or taste buds, are known in considerable detail, general knowledge about primary mouth formation is regrettably low. In this paper, primary mouth formation is reviewed from a comparative point of view in order to reveal its underestimated morphogenetic diversity among, and also within, particular vertebrate clades. In general, three main developmental modes were identified. The most common is characterized by primary mouth formation via a deeply invaginated ectodermal stomodeum and subsequent rupture of the bilaminar oral membrane. However, in salamander, lungfish and also in some frog species, the mouth develops alternatively via stomodeal collar formation contributed both by the ecto‐ and endoderm. In ray‐finned fishes, on the other hand, the mouth forms via an ectoderm wedge and later horizontal detachment of the initially compressed oral epithelia with probably a mixed germ‐layer derivation. A very intriguing situation can be seen in agnathan fishes: whereas lampreys develop their primary mouth in a manner similar to the most common gnathostome pattern, hagfishes seem to undergo a unique oropharyngeal morphogenesis when compared with other vertebrates. In discussing the early formative embryonic correlates of primary mouth formation likely to be responsible for evolutionary–developmental modifications of this area, we stress an essential role of four factors: first, positioning and amount of yolk tissue; closely related to, second, endoderm formation during gastrulation, which initiates the process and constrains possible evolutionary changes within this area; third, incipient structure of the stomodeal primordium at the anterior neural plate border, where the ectoderm component of the prospective primary mouth is formed; and fourth, the prime role of Pitx genes for establishment and later morphogenesis of oral region both in vertebrates and non‐vertebrate chordates.
Lactate production as a response to intrapartum hypoxia in the growth‐restricted fetus
Authors: Holzmann M , Cnattingius S , Nordström L 
Published: July 2012

Please cite this paper as: Holzmann M, Cnattingius S, Nordström L. Lactate production as a response to intrapartum hypoxia in the growth‐restricted fetus. BJOG 2012;119:1265–1269.Objective  To analyse whether the increase in lactate in response to intrapartum hypoxia differs between small‐ (SGA), appropriate‐ (AGA) and large‐for‐gestational‐age (LGA) fetuses.Design  Observational cohort study.Setting  Ten obstetric units in Sweden.Population  A cohort of 1496 women.Methods  A secondary analysis of a randomised controlled trial, in which 1496 women with fetal heart rate abnormalities, indicating fetal scalp blood sampling, were randomised to lactate analyses. After delivery, the neonates were divided according to birthweight for gestational age into SGA, AGA and LGA groups.Main outcome measure  Lactate concentration in fetal scalp blood.Secondary outcome measures  Acid–base balance in cord artery blood and Apgar score <7 at 5 minutes.Results  Median lactate concentrations in the SGA, AGA and LGA groups were 3.8, 3.0 and 2.2 mmol/l, respectively (SGA versus AGA, P = 0.017; LGA versus AGA, P = 0.009). In the subgroups with scalp lactate >4.8 mmol/l (lactacidaemia), the corresponding median (range) values were 6.2 (4.9–14.6), 5.9 (4.9–15.9) and 5.7 mmol/l (5.0–7.9 mmol/l), respectively (no significant differences between the groups). The proportions of neonates with cord artery pH < 7.00, metabolic acidaemia or Apgar score <7 at 5 minutes were similar in all weight groups.Conclusion  SGA fetuses with fetal heart rate abnormalities have the same ability to produce lactate as a response to intrapartum hypoxia as AGA and LGA fetuses. The risk of a poor outcome associated with high lactate concentration is the same in SGA, AGA and LGA fetuses. Scalp blood lactate analysis is therefore a reliable method for intrapartum fetal surveillance of suspected growth‐restricted fetuses scheduled for vaginal delivery at ≥34 weeks of gestation.
A comparative assessment of univariate longevity measures using zoological animal records
Authors: Moorad Jacob A. , Promislow Daniel E. L. , Flesness Nate , Miller Richard A. 
Published: July 2012

SummaryComparative biogerontology evaluates cellular, molecular, physiological, and genomic properties that distinguish short‐lived from long‐lived species. These studies typically use maximum reported lifespan (MRLS) as the index with which to compare traits, but there is a general awareness that MRLS is not ideal owing to statistical shortcomings that include bias resulting from small sample sizes. Nevertheless, MRLS has enough species‐specific information to show strong associations with many other species‐specific traits, such as body mass, stress resistance, and codon usage. The major goal of this study was to see if we could identify surrogate measures with better statistical properties than MRLS but that still capture inter‐species differences in extreme lifespan. Using zoological records of 181 bird and mammal species, we evaluated 16 univariate metrics of aging and longevity, including nonparametric quantile‐based measures and parameters derived from demographic models of aging, for three desirable statistical properties. We wished to identify those measures that: (i) correlated well with MRLS when the biasing effects of sample size were removed; (ii) correlated weakly with population size; and (iii) were highly robust to the effects of sampling error. Nonparametric univariate descriptors of the distribution of lifespans clearly outperformed the measures derived from demographic analyses. Mean adult lifespan and quantile‐based measures, and in particular the 90th quantile of longevity, performed particularly well, demonstrating far less sensitivity to small sample size effects than MRLS while preserving much of the information contained in the maximum lifespan measure. These measures should take the place of MRLS in comparative studies of lifespan.
The effects of some β‐adrenoreceptor blocking drugs on the uptake and release of noradrenaline by the heart
Authors: FOO J. W. , JOWETT ALISON , STAFFORD ANNE 
Published: July 2012

The potencies of some β‐adrenoreceptor blocking drugs in reducing noradrenaline uptake by the isolated heart were compared with their potencies in reducing the release of noradrenaline from the heart by tyramine.
Of the drugs tested, propranolol, pronethalol and dichloroisoprenaline were the most potent in blocking uptake and release of noradrenaline, although none was at potent as cocaine; MJ 1999 and I.C.I. 50172 were only weakly effective.
Pronethalol and dichloroisoprenaline each reduced release of noradrenaline by tyramine in the concentration range (10−7–10−6M) where blockade of responses to tyramine was apparent; with these drugs both reduction of noradrenaline release and β‐receptor blockade contribute to the reduction in responses to tyramine.
Potency of β‐receptor blocking drugs in reducing noradrenaline uptake is unrelated to potency in blocking β‐receptors; Kö 592 blocks β‐receptors without affecting noradrenaline uptake.
Effects of quaternary ammonium compounds on choline transport in red cells
Authors: MARTIN K. 
Published: July 2012

Neuromuscular blocking agents have been shown to be powerful inhibitors of choline transport in human erythrocytes. Ganglionic blocking agents were weaker inhibitors.
The affinity of the choline transport site for alkyltrimethylammonium compounds was considerably higher than its affinity for alkyl‐bis‐(trimethylammonium) compounds of similar chain length. The affinity increases with increasing length of the alkyl chain in both series.
Tetramethylammonium (TMA), ethyl‐ and propyltrimethylammonium appear to enter the cells on the choline carrier while the larger monoquaternary compounds, and the bisquaternary compounds, bind to the carrier but are unable to cross the cell membrane.
Radioactively labelled carbachol, acetylcholine and decamethonium do not enter the cells on the choline carrier.
Choline transport in erythrocytes from patients with myasthenia gravis is normal, suggesting that this disorder is not associated with a generalized defect of choline transport.
Some hepatotoxic actions of hexachloroethane and its metabolites in sheep
Authors: FOWLER J. S. L. 
Published: July 2012

Pentachloroethane and tetrachloroethylene were major metabolites of hexachloroethane in sheep.
Concentrations of hexachloroethane, pentachloroethane and tetrachloroethylene were determined by gas‐liquid chromatography in blood, bile, faeces, urine and tissues after oral administration of hexachloroethane emulsions to sheep.
Increased blood concentrations of sorbitol dehydrogenase, glutamate dehydrogenase, and ornithine carbamoyl transferase were found to follow oral administration of hexachloroethane or pentachloroethane.
The rate of bromsulphthalein transfer from liver cells to bile was found to decrease after oral administration of hexachloroethane.
Partial purification of the anti‐inflammatory factor(s) in inflammatory exudate
Authors: BILLINGHAM M. E. J. , ROBINSON B. V. , ROBSON J. M. 
Published: July 2012

The carrageenin foot test was established as a sensitive and reliable assay procedure for determining the anti‐inflammatory activity of inflammatory exudates.
Incubation alone at a temperature above 70° C or with pronase at 37° C destroyed the anti‐inflammatory activity of exudate.
The anti‐inflammatory component of exudate was partially precipitated by 50% ammonium sulphate.
A partial purification process was devised using Sephadex G‐150 gel filtration and DEAE and CM cellulose ion exchange chromatography to obtain at least a 24 fold purification.
Measurements of 11‐hydroxycorticosteroid levels indicated that steroids were not involved in the mechanism by which the exudate produced its antiinflammatory effects.
The effects of iproniazid and reserpine on the accumulation of granular vesicles and noradrenaline in constricted adrenergic nerves
Authors: BANKS P. , KAPELLER K. , MAYOR D. 
Published: July 2012

. The accumulation of granular vesicles proximal to a constriction applied to hypogastric nerves has been investigated with the electron microscope in cats treated with reserpine and/or iproniazid.
. The ultrastructural changes have been correlated with the accumulation of noradrenaline at the same site in similarly treated animals.
. The findings give further support to the view that granular vesicles constitute a major storage site for intraneuronal noradrenaline.
The strychnine‐like action of curare and related compounds on the somatosensory evoked response of the rat cortex
Authors: BHARGAVA V. K. , MELDRUM B. S. 
Published: July 2012

. Drugs were applied to the cerebral cortex of rats anaesthetized with pentobarbitone and changes measured in the somatosensory primary evoked response.
. Computer‐derived averages of thirty‐two consecutive responses yielded stable and consistent measurements of the potential changes comprising the evoked response, and comparable records from the opposite (non‐drug treated) cortex provided an essential control for systemic actions of the drug.
. The modifications produced by curare and strychnine were indistinguishable. The first positive wave (peak latency 7 msec) was unaltered; the second positive wave (peak latency 11.5 msec) was variably enhanced, and the first and second negative waves (peak latencies 16 and 40 msec) were replaced by a much larger negative wave (peak latency 22 msec).
. The time of onset of the effect on the negative waves and the maximal amplitude attained by the abnormal negative wave were related to the log concentration of the drug used. Curare is approximately 10 times more potent than strychnine.
. Toxiferine I, di‐allylnortoxiferine and atropine also produced this effect but were less potent than strychnine.
. Succinylcholine, dihydro‐β‐erythroidine and gallamine triethiodide did not produce this effect (in concentrations up to 10−3M).
. The observations are consistent with an action of curare and strychnine on an intracortical cholinergic inhibitory system, but other possibilities including a “non‐specific excitatory action” cannot be excluded.