bluuebunny/crossref_metadata_2025 huggingface dataset:
The invasion ecology of mammals: a global perspective
Authors: Clout Mick N. , Russell James C.
Published: May 2008

Of the extant species of land mammals, 124 (2.6%) can be classed as ‘successful invaders’, whereas 1038 (21.6%) are classed as threatened, according to the 2006 IUCN Red List. Relatively high proportions of successful invaders are found among Artiodactyla, Carnivora, Lagomorpha and Perissodactyla. Compared with other organisms, mammals seem relatively likely to become established when introduced outside their natural range. Studies of determinants of invasion success indicate that the number of individuals released, the size of the natural range of the introduced species, and the temperateness of climate in the new range can all increase the probability of establishment of introduced mammals. Negative impacts of invasive mammals on native biodiversity include direct effects such as predation, browsing and competition, but can extend to disruption of patterns of nutrient flow, and trophic cascades. Eradication of several species of invasive mammals from increasingly large areas is now possible. In this context, it is important to better understand ecological interactions between such mammals (and between them and other species) to avoid unwanted consequences such as mesopredator or competitor release, after the removal of particular species. Finally, it is increasingly apparent that research is needed on the behaviour of dispersing and invading individuals, to improve the early detection of new mammal invasions or reinvasions.
Tracking non-native vertebrate species: indicator design for the United States of America
Authors: Meyerson Laura A. , Engeman Richard , O'Malley Robin
Published: May 2008

Basic information on the distribution, spread and impacts of non-native species in the USA is not available to those who shape national environmental policy. Although the USA spends billions of dollars annually on introduced species research, monitoring and control efforts, only a limited number of government agencies or private institutions are able to provide definitive reports on more than a handful of these species at a national scale. Research on invasive species is only of marginal practical value if the information cannot be succinctly and effectively transmitted to those who determine the management policies, budgets and objectives. To remedy this situation, a national-scale approach for monitoring established non-native species has been developed under the auspices of the Heinz Center as part of ‘The State of the Nation’s Ecosystems’ project. This paper specifically describes the strategies for reporting on indicators for non-native vertebrate species developed through inputs by experts from academia, industry, environmental organisations and government.
The roles of risk assessment in the control of invasive vertebrates
Authors: Andersen Mark C.
Published: May 2008

Vertebrate pest species are an economically and ecologically important subset of the broader environmental problem of invasive alien species. Risk assessment has been shown to be a useful paradigm for identifying and comparing potential solutions to environmental problems in a variety of contexts, including problems associated with invasive species. Here I briefly review the important components of the risk assessment paradigm, and discuss potential applications of risk assessment approaches to several aspects of the control of invasive vertebrate pest species, including import and export controls to prevent establishment, evaluation of control measures for established species, and assessment of the severity of potential non-target impacts of control measures. Risk assessment can contribute to the solution of vertebrate pest problems by connecting science to policy and management decisions, by identifying and alleviating values-based controversies, and by integrating public participation and stakeholder involvement into science-based decision-making.
Lessons from introductions of exotic species as a possible information source for managing translocations of birds
Authors: Cassey Phillip , Blackburn Tim M. , Duncan Richard P. , Lockwood Julie L.
Published: May 2008

It has been previously suggested that the characteristics that are driving the taxonomic homogenisation of the global avifauna, through the extinction of native bird species and the establishment of exotic bird species, are opposite sides of the same coin. One of the most important tools that conservation biologists and wildlife managers have to ameliorate the extinction of a species is to reintroduce populations to stronghold areas from which they have been extirpated or were not previously common. In this paper, we address the question of what the study of exotic bird introductions can tell us to inform the translocation of native species. We review the relative importance of the five factors that have been suggested significantly to influence the successful establishment of non-native species: introduction effort, environmental matching, species’ interactions, species’ life histories, and phylogenetic relatedness. Current evidence suggests that introduction effort will be an important determinant of release, but how many individuals need to be released, and in how many separate release events, is contingent on characteristics of species and environment. The importance of climate matching for introduction success suggests that the success of translocations will depend greatly on the study and amelioration of the problem that caused the initial population decline. This is most problematic in situations where the decline is associated with human-induced climate change. Migratory and sexually selected species may be harder to re-establish, but related species may differ substantially in their likelihood of success. We suggest that further insights into the reintroduction process may be gained particularly by studying species that are experiencing a threat in their native range but which are also being widely released as exotics outside of this range.
Synergies between climate change, extinctions and invasive vertebrates
Authors: Brook Barry W.
Published: May 2008

There is mounting evidence for the direct ecological impacts of recent climate change, and for amplifying feedbacks, in both directions, with other drivers of biodiversity loss, such as habitat fragmentation and overexploitation. Surprisingly, however, empirical and experimental data on the links between climate change and species introductions are scant, especially for invasive vertebrates. Because the theoretical basis for their mutually reinforced impact is strong, this dearth of evidence likely reflects the difficulty in studying such interactions, and insufficient attention to this topic, rather than a genuine lack of association. Given the unprecedented rate of recent and predicted future climate change, and the continued exponential rise in species invasions worldwide, it is imperative that we sharpen our scientific focus so as to best equip wildlife managers with the knowledge to tackle this inevitable synergy of threats.
Alien invasive vertebrates in ecosystems: pattern, process and the social dimension
Authors: White Piran C. L. , Ford Adriana E. S. , Clout Mick N. , Engeman Richard M. , Roy Sugoto , Saunders Glen
Published: May 2008

The rate of biological invasions has increased dramatically over recent centuries. Alien invasive vertebrates have significant adverse effects on biodiversity, and island fauna are especially susceptible. Human-induced environmental change is likely to exacerbate these negative impacts of alien invasive species. However, invasion biology has advanced considerably over the last two decades, with improvement in understanding of the processes of establishment and spread. New developments in spatial modelling have elucidated the way in which behavioural processes at the individual level can drive population-level patterns such as spread. Combined with new genetic insights into the process of invasion, these advances may assist in the development of novel, better-targeted management strategies that provide new options in how to deal with the threat posed by invasive species. Decisions about whether to and how we should intervene are questions for all sectors of society, but research on the social and cultural impacts of invasive species is largely lacking. There are many opportunities for enhancing the social dimensions of invasive species research, and integrated assessments of the social, economic and environmental impacts of species provide one potential avenue. As part of this, there is also a need to increase stakeholder participation in the decision-making process regarding alien invasive species. These more holistic approaches are essential if we are to reduce the impact of alien invasive species to within acceptable limits in the face of rapid environmental change.
Mixing against culture vs mixing against nature: Ontologization of prohibited interethnic relationships
Authors: Roncarati Alessandra , Pérez Juan A. , Ravenna Marcella , Navarro‐Pertusa Esperanza
Published: May 2008

In this paper, we develop the theory of ontologization: Social representations that prevent members of minority and majority groups who are living in contact with each other to mingle. The process of ontologization consists of separating some humans from their own species, and anchoring them in another environment, that of an animal, for example. We propose that underlying the famous slogan “equal but separate” is the social representation of interracial mixing as a “counter‐nature” phenomenon. It is predicted that a sexual relationship between people of different “races” leads to a greater degree of ontologization, and, as such, this miscegenation will be explained in terms of biologistic thinking, like an instinctive nature or atavistic animal impulse. An experiment (N = 360) features the case of a woman who, though already in a stable relationship, is unfaithful to her partner. In a 2×3 factor design, the ethnic‐national identity of this woman (in‐group: Spanish/Italian vs out‐group: Senegalese) and the ethnic‐national identity of her lovers (in‐group: Spanish/Italian vs out‐group: Rumanian vs out‐group: Senegalese) were manipulated. In general, results fit the hypothesis of ontologization in interracial conditions better, rather than the customary in‐group favouritism and/or out‐group discrimination bias. We then go on to discuss the way in which a biologistic way of thinking enables a differentiation at the human level, in terms of culture groups and nature groups, in “races,” so that an interracial sexual relationship is seen as evidence of a wild and irrepressible impulse, which stigmatizes the people involved in these relationships.
Activation of oligodendroglial Fyn kinase enhances translation of mRNAs transported in hnRNP A2–dependent RNA granules
Authors: White Robin , Gonsior Constantin , Krämer-Albers Eva-Maria , Stöhr Nadine , Hüttelmaier Stefan , Trotter Jacqueline
Published: May 2008

Central nervous system myelination requires the synthesis of large amounts of myelin basic protein (MBP) at the axon–glia contact site. MBP messenger RNA (mRNA) is transported in RNA granules to oligodendroglial processes in a translationally silenced state. This process is regulated by the trans-acting factor heterogeneous nuclear ribonucleoprotein (hnRNP) A2 binding to the cis-acting A2 response element (A2RE). Release of this repression of MBP mRNA translation is thus essential for myelination. Mice deficient in the Src family tyrosine kinase Fyn are hypomyelinated and contain reduced levels of MBP. Here, we identify hnRNP A2 as a target of activated Fyn in oligodendrocytes. We show that active Fyn phosphorylates hnRNP A2 and stimulates translation of an MBP A2RE–containing reporter construct. Neuronal adhesion molecule L1 binding to oligodendrocytes results in Fyn activation, which leads to an increase in hnRNP A2 phosphorylation. These results suggest that Fyn kinase activation results in the localized translation of MBP mRNA at sites of axon–glia contact and myelin deposition.
Neural RNA-binding protein Musashi1 inhibits translation initiation by competing with eIF4G for PABP
Authors: Kawahara Hironori , Imai Takao , Imataka Hiroaki , Tsujimoto Masafumi , Matsumoto Ken , Okano Hideyuki
Published: May 2008

Musashi1 (Msi1) is an RNA-binding protein that is highly expressed in neural stem cells. We previously reported that Msi1 contributes to the maintenance of the immature state and self-renewal activity of neural stem cells through translational repression of m-Numb. However, its translation repression mechanism has remained unclear. Here, we identify poly(A) binding protein (PABP) as an Msi1-binding protein, and find Msi1 competes with eIF4G for PABP binding. This competition inhibits translation initiation of Msi1's target mRNA. Indeed, deletion of the PABP-interacting domain in Msi1 abolishes its function. We demonstrate that Msi1 inhibits the assembly of the 80S, but not the 48S, ribosome complex. Consistent with these conclusions, Msi1 colocalizes with PABP and is recruited into stress granules, which contain the stalled preinitiation complex. However, Msi1 with mutations in two RNA recognition motifs fails to accumulate into stress granules. These results provide insight into the mechanism by which sequence-specific translational repression occurs in stem cells through the control of translation initiation.
Similar active genes cluster in specialized transcription factories
Authors: Xu Meng , Cook Peter R.
Published: May 2008

How transcription affects the way specific genes are arranged within the nucleus remains to be fully understood. We examine here whether transcription occurs in discrete sites (factories) containing the required machinery and whether these sites specialize in transcribing different genes. We cotransfected plasmids encoding a common origin of replication but different transcription units into cells, where they are assembled into minichromosomes that the cellular machinery replicates and transcribes. In cells containing thousands of minichromosomes, we found (using fluorescence in situ hybridization) active templates concentrated in only a few factories that transcribe particular units depending on the promoter type and the presence of an intron. Close proximity between similar transcription units, whether on two different minichromosomes or on host chromosomes and minichromosomes, is confirmed using chromosome conformation capture. We conclude that factories specialize in producing a particular type of transcript depending on promoter type and whether or not the gene contains an intron.
Myofiber integrity depends on desmin network targeting to Z-disks and costameres via distinct plectin isoforms
Authors: Konieczny Patryk , Fuchs Peter , Reipert Siegfried , Kunz Wolfram S. , Zeöld Anikó , Fischer Irmgard , Paulin Denise , Schröder Rolf , Wiche Gerhard
Published: May 2008

Dysfunction of plectin, a 500-kD cytolinker protein, leads to skin blistering and muscular dystrophy. Using conditional gene targeting in mice, we show that plectin deficiency results in progressive degenerative alterations in striated muscle, including aggregation and partial loss of intermediate filament (IF) networks, detachment of the contractile apparatus from the sarcolemma, profound changes in myofiber costameric cytoarchitecture, and decreased mitochondrial number and function. Analysis of newly generated plectin isoform–specific knockout mouse models revealed that IF aggregates accumulate in distinct cytoplasmic compartments, depending on which isoform is missing. Our data show that two major plectin isoforms expressed in muscle, plectin 1d and 1f, integrate fibers by specifically targeting and linking desmin IFs to Z-disks and costameres, whereas plectin 1b establishes a linkage to mitochondria. Furthermore, disruption of Z-disk and costamere linkages leads to the pathological condition of epidermolysis bullosa with muscular dystrophy. Our findings establish plectin as the major organizer of desmin IFs in myofibers and provide new insights into plectin- and desmin-related muscular dystrophies.
c-Jun is a negative regulator of myelination
Authors: Parkinson David B. , Bhaskaran Ambily , Arthur-Farraj Peter , Noon Luke A. , Woodhoo Ashwin , Lloyd Alison C. , Feltri M. Laura , Wrabetz Lawrence , Behrens Axel , Mirsky Rhona , Jessen Kristján R.
Published: May 2008

Schwann cell myelination depends on Krox-20/Egr2 and other promyelin transcription factors that are activated by axonal signals and control the generation of myelin-forming cells. Myelin-forming cells remain remarkably plastic and can revert to the immature phenotype, a process which is seen in injured nerves and demyelinating neuropathies. We report that c-Jun is an important regulator of this plasticity. At physiological levels, c-Jun inhibits myelin gene activation by Krox-20 or cyclic adenosine monophosphate. c-Jun also drives myelinating cells back to the immature state in transected nerves in vivo. Enforced c-Jun expression inhibits myelination in cocultures. Furthermore, c-Jun and Krox-20 show a cross-antagonistic functional relationship. c-Jun therefore negatively regulates the myelinating Schwann cell phenotype, representing a signal that functionally stands in opposition to the promyelin transcription factors. Negative regulation of myelination is likely to have significant implications for three areas of Schwann cell biology: the molecular analysis of plasticity, demyelinating pathologies, and the response of peripheral nerves to injury.
Assessment of Behavior during Labor in Rats and Effect of Intrathecal Morphine
Authors: Tong Chuanyao , Conklin Dawn R. , Liu Baogang , Ririe Douglas G. , Eisenach James C.
Published: May 2008

Background

Efficacy of analgesics varies with the type of pain. Little is known in this regard concerning labor pain, given the ethical barriers to study in humans and the lack of surrogate animal models. To address this, the authors classified and quantified spontaneous behaviors during labor and delivery in rats and examined the effects of a known analgesic, intrathecal morphine.

Methods

Pregnant rats were video recorded for 72 h surrounding the time of anticipated labor and delivery. Specific behaviors were identified and classified into general activities, phasic stretching behaviors, and maternal attention activities. Rats received intrathecal infusion of saline or morphine, 0.035-3.5 microg/h, beginning approximately 1 day before delivery, and effects on behaviors and response to noxious heating of the paw were quantified.

Results

Phasic stretching behaviors occurred with high frequency before delivery of the first pup and were rare after delivery of the last pup. Intrathecal morphine at infusion rates greater than 0.035 microg/h abolished these behaviors without affecting general or maternal behaviors or the timing or duration of labor and delivery. Morphine was also antinociceptive to noxious heat, but only at infusion rates of 1.0 microg/h or higher.

Conclusions

Phasic stretching behaviors are observed after distension or inflammation of pelvic viscera in rats, and similar behaviors occur during labor and delivery. Selective and dose-related blockade by intrathecal morphine of only these behaviors suggests that they reflect nociception and that this simple monitoring method can be used to study therapies for the pain of labor and delivery.
Epidural Analgesia Enhances the Postoperative Anabolic Effect of Amino Acids in Diabetes Mellitus Type 2 Patients Undergoing Colon Surgery
Authors: Lugli Andrea Kopp , Donatelli Francesco , Schricker Thomas , Wykes Linda , Carli Franco
Published: May 2008

Background

It has been suggested that diabetes mellitus type 2 amplifies the endocrine-metabolic stress response to surgery, and patients become more catabolic during the postoperative period. The aim of this study, conducted in patients with diabetes mellitus type 2 scheduled to undergo elective colorectal surgery, was to determine whether the anabolic effects of intravenous amino acids are more pronounced when receiving perioperative epidural analgesia compared with patient-controlled analgesia with intravenous morphine.

Methods

Twelve patients were randomly assigned to receive either epidural analgesia or patient-controlled analgesia with intravenous morphine for perioperative pain control. Protein and glucose kinetics were measured before surgery and on the second postoperative day using L-[1-C]leucine and [6,6H2]glucose infusion during a fasted and a fed (amino acid infusion) state.

Results

Preoperative parameters for glucose and protein kinetics were comparable in the fasted state for both groups. Postoperative amino acid infusion increased glucose concentration slightly (P = 0.124) and suppressed the endogenous rate of appearance of glucose (P < 0.0001) and glucose clearance (P < 0.0001) regardless of analgesia technique. The rate of appearance of leucine (P = 0.002), leucine oxidation (P < 0.0001), and protein synthesis (P = 0.026) increased, whereas net protein breakdown was decreased (P = 0.002), leading to a positive protein balance (P < 0.0001) in both groups. The increase in protein balance was greater in the epidural group compared with the patient-controlled analgesia group (P = 0.027).

Conclusion

Diabetic patients receiving an amino acid infusion after surgery achieved a positive protein balance without hyperglycemia. This anabolic effect was greater in patients receiving epidural analgesia compared with patient-controlled analgesia with intravenous morphine.
Postconditioning with Isoflurane Reduced Ischemia-induced Brain Injury in Rats
Authors: Lee Jeong Jin , Li Liaoliao , Jung Hae-Hyuk , Zuo Zhiyi
Published: May 2008

Background

Preexposure of brain to isoflurane, a commonly used anesthetic, induces ischemic tolerance. This phenomenon is called isoflurane preconditioning. However, it is not known whether isoflurane application after ischemia provides neuroprotection.

Methods

Corticostriatal slices (400 microm) freshly prepared from adult male Sprague-Dawley rats were subjected to a 15-min oxygen-glucose deprivation (OGD; to simulate ischemia in vitro). Isoflurane was applied after OGD. Brain slices were harvested 2 h after OGD for measuring 2,3,5-triphenyltetrazolium chloride (TTC) conversion to quantify cell injury. Adult male Sprague-Dawley rats were also subjected to middle cerebral arterial occlusion for 90 min and then treated with or without 2% isoflurane for 60 min started at the onset of reperfusion. The infarct volumes, neurologic deficit scores, and performance on rotarod were evaluated at 24 h after the onset of reperfusion.

Results

Isoflurane applied immediately after the 15-min OGD for 30 min dose-dependently reversed the OGD-induced decrease of TTC conversion. The TTC conversion was 34 +/- 16% and 58 +/- 28% of the control, respectively, for OGD alone and OGD plus 2% isoflurane (P < 0.05, n = 12). Application of 2% isoflurane for 30 min started at 10 min after the OGD also reduced the OGD-decreased TTC conversion. The presence of 0.3 microm glibenclamide, a general adenosine 5'-triphosphate-sensitive potassium channel blocker, or 500 microm 5-hydroxydecanoic acid, a mitochondrial adenosine 5'-triphosphate-sensitive potassium channel blocker, during the application of 2% isoflurane abolished the isoflurane preservation of TTC conversion. Application of isoflurane during reperfusion also improved neurologic outcome after brain ischemia.

Conclusions

The results suggest that isoflurane administrated after OGD or brain ischemia provides neuroprotection. Mitochondrial adenosine 5'-triphosphate-sensitive potassium channels may be involved in this protection.
Front Teeth–to–Carina Distance in Children Undergoing Cardiac Catheterization
Authors: Hunyady Agnes I. , Pieters Benjamin , Johnston Troy A. , Jonmarker Christer
Published: May 2008

Background

Knowledge of normal front teeth-to-carina distance (FT-C) might prevent accidental bronchial intubation. The aim of the current study was to measure FT-C and to examine whether the Morgan formula for oral intubation depth, i.e., endotracheal tube (ETT) position at front teeth (cm) = 0.10 x height (cm) + 5, gives appropriate guidance when intubating children of different ages.

Methods

FT-C was measured in 170 infants and children, aged 1 day to 19 yr, undergoing cardiac catheterization. FT-C was obtained as the sum of the ETT length at the upper front teeth/dental ridge and the distance from the ETT tip to the carina. The latter measure was taken from an anterior-posterior chest x-ray.

Results

There was close linear correlation between FT-C and height: FT-C (cm) = 0.12 x height (cm) + 5.2, R = 0.98. The linear correlation coefficients (R) for FT-C versus weight and age were 0.78 and 0.91, respectively. If the Morgan formula had been used for intubation, the ETT tip would have been at 90 +/- 4% of FT-C. No patient would have been bronchially intubated, but the ETT tip would have been less than 0.5 cm from the carina in 13 infants.

Conclusions

FT-C can be well predicted from the height/length of the child. The Morgan formula provides good guidance for intubation in children but can result in a distal ETT tip position in small infants. Careful auscultation is necessary to ensure correct tube position.
Volatile Anesthetic Effects on Midbrain-elicited Locomotion Suggest that the Locomotor Network in the Ventral Spinal Cord Is the Primary Site for Immobility
Authors: Jinks Steven L. , Bravo Milo , Hayes Shawn G.
Published: May 2008

Background

Volatile anesthetics produce immobility primarily by action in the spinal cord; however, anesthetic effects among different neuronal classes located in different spinal regions, and how they relate to immobility, are not understood.

Methods

In decerebrated rats, effects of isoflurane and halothane on movement elicited by electrical microstimulation of the mesencephalic locomotor region (MLR) were assessed in relation to minimum alveolar concentration (MAC). Anesthetic effects on step frequency and isometric limb force were measured. The authors also examined effects of MLR stimulation on responses of nociceptive dorsal horn neurons and limb force responses to tail clamp.

Results

Mean isoflurane requirements to block MLR-elicited stepping were slightly but significantly greater than MAC by 10%. Mean halothane requirements to block MLR-elicited stepping were greater than those for isoflurane and exceeded MAC by 20%. From 0.4 to 1.3 MAC (but not 0.0 to 0.4 MAC), there was a dose-dependent reduction in the frequency and force of hind limb movements elicited by MLR stimulation during both anesthetics. MLR stimulation inhibited noxious stimulus evoked responses of dorsal horn neurons by approximately 80%. Aptly, MLR stimulation produced analgesia that outlasted the midbrain stimulus by at least 15 s, as indicated by an 81% reduction in hind limb force elicited noxious tail clamp.

Conclusions

Because electrical stimulation of the MLR elicits movement independent of dorsal horn activation, the immobilizing properties of isoflurane and halothane are largely independent of action in the dorsal horn. The results suggest that volatile anesthetics produce immobility mainly by action on ventral spinal locomotor networks.
Effect of AMG0347, a Transient Receptor Potential Type V1 Receptor Antagonist, and Morphine on Pain Behavior after Plantar Incision
Authors: Wu Chaoran , Gavva Narender R. , Brennan Timothy J.
Published: May 2008

Background

Studies on postoperative pain examine the etiology of incisional pain with the goal to develop new treatments for patients' pain after surgery. The current study examined the analgesic effects of a recently developed transient receptor potential vanilloid 1 (TRPV1) antagonist, AMG0347, on incisional pain in rats. Doses of morphine lower than those used in most rodent studies were also examined.

Methods

Adult Sprague-Dawley rats were underwent plantar incision. The effect of either AMG0347 or morphine was tested for its effects on guarding pain score, heat withdrawal latency, and mechanical withdrawal threshold. AMG0347 was also tested against nociceptive behaviors caused by capsaicin.

Results

For incisional pain, AMG0347 did not change the withdrawal threshold to mechanical stimulation or the guarding pain score. The withdrawal latency to heat increased from 3 h through 1 day after AMG0347 administration. AMG0347 prevented the decreases in heat withdrawal latency and mechanical withdrawal threshold caused by capsaicin infiltration and prevented the increase in activity caused by intrathecal capsaicin injection. Doses of morphine less than 1 mg/kg inhibited both the guarding and heat hyperalgesia; only the 1-mg/kg does affected mechanical responses.

Conclusions

AMG0347 decreased capsaicin-induced heat and mechanical hyperalgesia and blocked central TRPV1 receptors. AMG0347 only decreased heat hyperalgesia after plantar incision even though both peripheral and central TRPV1 receptors were blocked. The smallest doses of morphine affected guarding pain and heat responses.
Pregnancy Increases Excitability of Mechanosensitive Afferents Innervating the Uterine Cervix
Authors: Liu Baogang , Tong Chuanyao , Eisenach James C.
Published: May 2008

Background

Labor pain derives primarily from stimulation of afferents innervating the uterine cervix and lower uterine segment. The authors have previously shown that the excitability of these afferents is regulated by sex hormones and test in this study whether pregnancy also alters their excitability.

Methods

After animal care committee approval, Sprague-Dawley rats (nonpregnant, pregnant days 17 and 21) were anesthetized, and two metal rods were placed through the cervix for distension. The right hypogastric nerve was dissected and carefully teased until recording from a single unit was obtained. Spontaneous activity and the response to a graded distension (20-80 g) were recorded for off-line analysis.

Results

A total of 151 fiber units were recorded. Pregnancy was associated with an increase in spontaneous nerve activity in the absence of a mechanical stimulus (median of 0.98 and 1.56 Hz from pregnant days 17 and 21, respectively, compared with 0.45 Hz in nonpregnant; P < 0.01). The proportion of fibers responding to the weakest stimulus (20 g) was significantly greater in pregnant than in nonpregnant animals. The response to graded distension differed significantly among groups, with day 21 > day 17 > nonpregnant.

Conclusions

Afferents that innervate the uterine cervix sprout into this tissue during late pregnancy, and estrogen increases excitability of these mechanosensitive afferents. Here, the authors show that excitability also increases during pregnancy. These data suggest that, close to the onset of labor, there is an increased input to the spinal cord from cervical distension and an increased depolarization of afferent terminals in the cervix, effects that could influence pain and the progress of labor.
Carbon Monoxide Inhalation Reduces Pulmonary Inflammatory Response during Cardiopulmonary Bypass in Pigs
Authors: Goebel Ulrich , Siepe Matthias , Mecklenburg Anne , Stein Phillip , Roesslein Martin , Schwer Christian I. , Schmidt Rene , Doenst Torsten , Geiger Klaus K. , Pahl Heike L. , Schlensak Christian , Loop Torsten
Published: May 2008

Background

Cardiopulmonary bypass (CPB) is associated with pulmonary inflammation and dysfunction. This may lead to acute lung injury and acute respiratory distress syndrome with increased morbidity and mortality. The authors hypothesized that inhaled carbon monoxide before initiation of CPB would reduce inflammatory response in the lungs.

Methods

In a porcine model, a beating-heart CPB was used. The animals were either randomized to a control group, to standard CPB, or to CPB plus carbon monoxide. In the latter group, lungs were ventilated with 250 ppm inhaled carbon monoxide in addition to standard ventilation before CPB. Lung tissue samples were obtained at various time points, and pulmonary cytokine levels were determined.

Results

Hemodynamic parameters were largely unaffected by CPB or carbon monoxide inhalation. There were no significant differences in cytokine expression in mononuclear cells between the groups throughout the experimental time course. Compared with standard CPB animals, carbon monoxide significantly suppresses tumor necrosis factor-alpha and interleukin-1beta levels (P < 0.05) and induced the antiinflammatory cytokine interleukin 10 (P < 0.001). Carbon monoxide inhalation modulates effector caspase activity in lung tissue during CPB.

Conclusions

The results demonstrate that inhaled carbon monoxide significantly reduces CPB-induced inflammation via suppression of tumor necrosis factor alpha, and interleukin-1beta expression and elevation of interleukin 10. Apoptosis induced by CPB was associated with caspase-3 activation and was significantly attenuated by carbon monoxide treatment. Based on the observations of this study, inhaled carbon monoxide could represent a potential new therapeutic modality for counteracting CPB-induced lung injury.
Anatomical Balance of the Upper Airway and Obstructive Sleep Apnea
Authors: Tsuiki Satoru , Isono Shiroh , Ishikawa Teruhiko , Yamashiro Yoshihiro , Tatsumi Koichiro , Nishino Takashi
Published: May 2008

Background

Obesity and craniofacial abnormalities such as small maxilla and mandible are common features of patients with obstructive sleep apnea (OSA). The authors hypothesized that anatomical imbalance between the upper airway soft-tissue volume and the craniofacial size (rather than each alone) may result in pharyngeal airway obstruction during sleep, and therefore development of OSA.

Methods

Blind measurements of tongue cross-sectional area and craniofacial dimensions were performed through lateral cephalograms in 50 adult male patients with OSA and 55 adult male non-OSA subjects with various craniofacial dimensions.

Results

Maxillomandibular dimensions were matched between OSA and non-OSA groups. While the tongue was significantly larger in subjects with larger maxillomandible dimensions, OSA patients had a significantly larger tongue for a given maxillomandible size than non-OSA subjects. The hypothesis was also supported in subgroups matched for both body mass index and maxillomandible dimensions.

Conclusions

Upper airway anatomical imbalance is involved in the pathogenesis of OSA.
Trans-activator of Transcription-mediated Delivery of NEP1-40 Protein into Brain Has a Neuroprotective Effect against Focal Cerebral Ischemic Injury via Inhibition of Neuronal Apoptosis
Authors: Wang Qiang , Gou Xingchun , Xiong Lize , Jin Weilin , Chen Shaoyang , Hou Lichao , Xu Lixian
Published: May 2008

Background

The Nogo-66 antagonistic peptide (NEP1-40) is a potential candidate for therapeutic intervention of neuronal injury. However, delivery of the proteins across the blood-brain barrier is severely limited by its size and biochemical properties. The current study was designed to evaluate the transducible effects of the trans-activator of transcription (TAT) transduction system for NEP1-40 to cross the blood-brain barrier and to clarify whether intraperitoneal administration of TAT-NEP1-40 could protect cerebral neurons from ischemic injury.

Methods

Adult male Sprague-Dawley rats were submitted to a 120-min focal ischemia and received an intraperitoneal injection of No-TAT-NEP1-40, TAT-NEP1-40, TAT-beta-galactosidase, or vehicle. The existence of the proteins in the brain was analyzed with immunofluorescence and Western blot techniques at 6 h after injection. Brain ischemic injury was evaluated by neurologic deficit scores, infarction volumes, terminal deoxynucleotidyl transferase-mediated dUDP-biotin nick end labeling staining, and assay of caspase-3 activity.

Results

Western blot analysis and immunofluorescence staining confirmed the presence of TAT-NEP1-40 protein in the brains 6 h after injection. Intraperitoneal injection of TAT-NEP1-40 could attenuate the numbers of terminal deoxynucleotidyl transferase-mediated dUDP-biotin nick end labeling-positive cells and activated caspase-3 positive cells, and increase the viability of the cells in the ischemic bounder zone, compared with that treated with No-TAT-NEP1-40, TAT-beta-Gal, or vehicle. Furthermore, treatment with TAT-NEP1-40 significantly improved the neurologic outcomes and reduced the size of the infarction in rats.

Conclusions

The results demonstrate that the TAT-NEP1-40 could be efficiently delivered into the rat brains and improve ischemia-induced neurologic outcomes through attenuating cell apoptosis in ischemic brains.
Effect of Nitrous Oxide on Neuronal Damage and Extracellular Glutamate Concentration as a Function of Mild, Moderate, or Severe Ischemia in Halothane-anesthetized Gerbils
Authors: Taninishi Hideki , Takeda Yoshimasa , Kobayashi Motomu , Sasaki Toshihiro , Arai Minako , Morita Kiyoshi
Published: May 2008

Background

The effect of nitrous oxide on ischemic neuronal damage was quantitatively evaluated by use of logistic regression curves.

Methods

Seventy-two gerbils were anesthetized with 1% halothane and randomly assigned to receive 70% nitrous oxide or 70% nitrogen. Forebrain ischemia was performed for 3, 5, or 7 min, and direct-current potential in the hippocampal CA1 region was recorded. Histologic outcome was evaluated 5 days later. Relations of neuronal damage with ischemic duration and duration of ischemic depolarization were determined by logistic regression curves. In some animals, extracellular glutamate concentration was measured every 60 s during forebrain ischemia.

Results

Nitrous oxide increased neuronal damage only with 5 min of ischemia (nitrous oxide vs. nitrogen: 78.5 +/- 23.0 vs. 37.3 +/- 12.2%; P < 0.01). The percentages of neuronal damage with 3 and 7 min of ischemia were not different with or without nitrous oxide. Logistic regression curves indicated that nitrous oxide significantly increased neuronal damage during the period from 3.07 to 6.63 min of ischemia. Logistic regression curves also indicated that nitrous oxide increased neuronal damage in the condition of the same duration of ischemic depolarization. Nitrous oxide shortened the ischemic duration necessary for causing 50% neuronal damage by 0.82 min. Dynamic change in extracellular glutamate concentration was not different (mean maximum dialysate glutamate concentration: 4.29 +/- 3.09 vs. 4.63 +/- 1.83 microm).

Conclusion

Administration of nitrous oxide caused an increase in ischemic neuronal damage, but a significant adverse effect was observed with a limited range of ischemic intervals.
The origins of uncooperative rhizobia
Authors: Sachs Joel L. , Simms Ellen L.
Published: May 2008

Mutualisms are thought to be destabilized by exploitative mutants that receive benefits from partners without reciprocation. Nonetheless, there is surprisingly little evidence for the spread of exploitation in mutualist populations. In particular mutualisms, non‐beneficial partners are commonplace and this raises the question of whether exploitation is invading as an adaptive strategy. Here, we highlight the legume–rhizobium mutualism as a key test case. Rhizobial bacteria fix nitrogen in legume roots in exchange for carbon from their hosts. However, non‐beneficial rhizobia are widespread, including non‐fixing and non‐nodulating strains. Recent research has shown that legumes can punish some uncooperative rhizobia and substantially reduce their fitness, but these sanctions must not be universally effective. Important questions about uncooperative rhizobia remain unresolved. (1) Is it adaptive for rhizobia to be uncooperative with hosts? (2) Do uncooperative rhizobia evolve from cooperative ancestors? (3) What are the mechanisms of rhizobial exploitation? We describe experimental approaches and testable hypotheses that address these gaps in our knowledge.
A parasite‐induced maternal effect can reduce survival times of fleas feeding on great tit nestlings
Authors: Gallizzi Katharina , Richner Heinz
Published: May 2008

Parents can increase their reproductive success by assisting their neonate offspring in parasite defence. In birds, parental tactics include post‐hatching parental responses such as increased parental care and pre‐hatching maternal effects such as the transfer of maternal antibodies via the egg. These parasite‐induced parental responses are known to reduce the effects of parasites on offspring, but their costs for the parasite are largely unknown. In two separate experiments on great titsParus majorwe assessed these costs for hen fleasCeratophyllus gallinae. Half of the parents where exposed to fleas during egg‐laying to induce the parental response, while control nests were left flea‐free. In experiment 1 parents raised their own young and we measured the effect of combined pre‐ and post‐hatching parental effects, while in experiment 2 a cross‐foster design allowed us to assess the effects of pre‐hatching maternal effects alone. In both experiments we let fleas take a blood meal on nestlings from either flea‐exposed or unexposed parents. We then measured flea‐feeding duration, the quantity of extracted blood, and the fleas’ subsequent survival time. We found in both experiments that on the largest nestlings of a brood flea survival was significantly reduced by the parental effects, whereas on the smaller nestlings it was independent of parental effects. The pre‐ and post‐hatching parental responses did neither affect duration nor size of a flea blood meal. These results suggest first that the pre‐hatching maternal effects, i.e. the substances transferred to the nestling via the egg, have the potential to harm fleas without reducing flea feeding capacity, and second that the strength of the maternal response varies between the nestlings, either because maternal products are unequally distributed among eggs within a clutch, or because large nestlings can build up a response that enhances the effect of the maternal products.
No maternal effects after stimulation of the melanization response in the yellow fever mosquito Aedes aegypti
Authors: Voordouw Maarten J. , Lambrechts Louis , Koella Jacob
Published: May 2008

The costs and benefits of activating the immune system can reach across generations. Thus, in vertebrates and in several invertebrates, stimulating the immune system of a female can enhance immunity of her offspring or decrease offspring fitness. We evaluated the potential maternally transmitted costs and benefits of the melanization response, an innate immune response of insects that helps to protect mosquitoes from malaria parasites. We manipulated the maternal melanization response of the yellow fever mosquito Aedes aegypti by inoculating female mosquitoes with negatively charged sephadex beads or with immunologically inert glass beads; a control group was not inoculated. In the next generation, we assayed the melanization response and measured three other life‐history traits: survival up to emergence, the age at emergence, and body size (estimated as wing length). We found no evidence of fitness costs or benefits for the offspring. A retrospective power analysis found that our experiment would have detected an effect size that is three times smaller than the maternal immune priming effects that have been reported in the literature. We did find a strong correlation between offspring wing length and melanization response. Overall, our findings indicate that trans‐generational immune priming in invertebrates cannot be generalized, and that it may depend on the species, the immune challenge, and the environmental conditions.
Placing butterflies on the map – testing regional geographical resolution of three stable isotopes in Sweden using the monophagus peacock Inachis io
Authors: Brattström Oskar , Wassenaar Leonard I. , Hobson Keith A. , Åkesson Susanne
Published: May 2008

Stable isotope analyses of tissues have been used to help delineate natal regions and routes of migratory animals. The foundations of such studies are isotopic gradients or differences representing geographic regions and habitat used by the organism that are retained in selected tissues. We sampled peacock butterflies Inachis io on a regional level in southern Sweden to study natural variation and the resolving power of the stable isotope method to delineate individuals from known areas on a smaller scale than has typically been used in previous studies. Hydrogen (δD), carbon (δ13C) and nitrogen (δ15N) isotopes were obtained from butterflies at seven different locations in an area of 250×250 km over three years (2002–2004). We found sufficient isotopic differences on this regional scale to delineate approximate origins. Of the three isotopes, deuterium showed good discrimination between sites, carbon isotopes showed weaker differentiation, whereas nitrogen isotopes proved unsuitable for small scale studies in this region due to high and unpredictable variation. We found there was enough variation in δD between years to prevent a general application of the technique to resolve sub‐regional variation. Substantial part of this variation was probably caused by seasonal changes in δD of precipitation. These differences produce significant variation in δD between years in animals having short and variable tissue development times, and are difficult to estimate in natural situations. We conclude that stable isotopes are potentially powerful predictors for studies of migratory butterflies in Europe. However, without good knowledge about the sampled individuals’ previous life‐history, a lot of the natural environmental variation in tissue δD cannot be controlled for. In the case of migratory species, this information is difficult to obtain, making the confidence intervals for prediction of natal areas fairly wide and probably only suitable for longer distance migration.
Genetic variation within the Lidia bovine breed
Authors: Cañón J. , Tupac‐Yupanqui I. , García‐Atance M. A. , Cortés O. , García D. , Fernández J. , Dunner S.
Published: May 2008

The results of an exhaustive data collection from a bovine population with a low level of exchangeability, the Lidia breed, are presented. A total of 1683 individuals from 79 herds were sampled and genetic diversity within and among lineages was assessed using 24 microsatellite loci on 22 different chromosomes. Expected heterozygosity ranged between 0.46 and 0.68 per lineage and there was significant inbreeding in the lineages, which included several farms [mean FIS = 0.11, bootstrap 95% confidence interval (0.09, 0.14)], mainly because of the high genetic divergence between herds within those lineages. High genetic differentiation between lineages was also found with a mean FST of 0.18 [bootstrap 95% confidence interval (0.17, 0.19)], and all pairwise values, which ranged from 0.07 to 0.35, were highly significant. The relationships among lineages showed weak statistical support. Nonetheless, lineages were highly discrete when analysed using correspondence analysis and a great proportion of the individuals were correctly assigned to their own lineage when performing standard assignment procedures.