bluuebunny/crossref_metadata_2025 huggingface dataset:
Oligomeric A2+ B3synthesis of highly branched polysulfone ionomers: novel candidates for ionic polymer transducers
Authors: Duncan Andrew J , Layman John M , Cashion Matthew P , Leo Donald J , Long Timothy E
Published: September 2009

Highly branched poly(arylene ether sulfone)s with systematically varied degrees of branching and sulfonation were synthesized through oligomeric A2+ B3methods for application as ionic polymer transducer (IPT) membranes. IPTs are a class of electroactive polymer devices that leverage ionomeric membranes to perform electromechanical transduction as actuators and/or sensors. Synthesis of controlled molecular weight A2oligomeric polysulfones targeted the global degree of branching (DBglobal) to approximately 1–3% in the absence of gelation. Size exclusion chromatography confirmed molecular weights greater than 20 000 g mol−1were achieved for linear and branched polysulfones. Increased degree of sulfonation of the A2oligomers reduced the development of molecular weight in the oligomeric A2+ B3branching reaction; the formation of tough, flexible, ion‐conducting membranes is required for emerging transducer applications. Variation in the DBglobalattained did not affect the thermal transitions or elastic modulus as significantly as changes in the degree of sulfonation. However, an ionic dissociation temperature was detected below the glass transition temperature of the polysulfone matrix and was relatively independent of the degree of sulfonation. Successful synthesis and characterization of these well‐defined branched polysulfone ionomers provide a basis for future investigation of polymer topology effects on IPT performance. Copyright © 2009 Society of Chemical Industry
Apport de l’échographie dans le bilan d’une infécondité masculine
Authors: Granier J. -L.
Published: September 2009

Présentation d’une assez longue expérience des examens échographiques conduits pour les bilans d’infécondité, sécrétoire par l’exploration du scrotum, excrétoire par l’exploration prostatique endorectale. Confrontations aux diverses pathologies retrouvées et détermination de la place de cette imagerie.
Aspects cliniques, biologiques et thérapeutiques de la cryptorchidie diagnostiquée à l’âge adulte: analyse d’une série de 69 cas
Authors: Fall B. , Fall P. A. , Ali M. , Diao B. , Sow Y. , Kaboré F. A. , Sarr A. , Ndoye A. K. , Diagne B. A.
Published: September 2009

But

Rapporter les aspects cliniques, biologiques et thérapeutiques de la cryptorchidie chez l’adulte et discuter de l’intérêt de l’abaissement du testicule non descendu (TND) chez l’adulte.

Patients et méthodes

Il s’agit d’une étude rétrospective colligeant 69 patients âgés de plus de 18 ans pris en charge au service d’urologie-andrologie du CHU Aristide-Le-Dantec pour cryptorchidie entre janvier 1999 et décembre 2007.

Résultats

L’âge moyen de nos patients était de 31,04 ± 8,4 ans (extrêmes 18 et 55 ans). Les principales circonstances de découverte ont été l’infertilité masculine (38 cas), la vacuité des bourses (21 cas) et la dégénérescence maligne du TND (six cas). La cryptorchidie était unilatérale dans 69,5 % et bilatérale dans 30,4 % des cas. Le spermogramme effectué chez 60 de nos patients a montré une azoospermie dans 46,6 % des cas, une oligozoospermie dans 38,3 % et une numération de spermatozoïdes normale dans 15 % des cas. Tous les patients ayant une cryptorchidie bilatérale avaient une azoospermie. À l’exploration chirurgicale, le TND a été retrouvé dans 95,6 % des cas (66 patients). Le principal type de traitement réalisé a été l’abaissement testiculaire. L’histologie des pièces d’orchidectomie sur testicule non tumoral (n= 7) a trouvé dans tous les cas une atrophie testiculaire sévère avec absence complète de cellules germinales. Les types histologiques des cancers étaient le séminome (n= 3) et le carcinome embryonnaire (n= 3). Parmi les patients ayant une azoospermie (n= 28), aucun cas d’induction de la spermatogenèse après abaissement testiculaire n’a été observé. Parmi les patients ayant consulté pour infertilité masculine, trois d’entre eux ont eu des enfants après abaissement testiculaire, soit un taux de paternité de 7,8 %.

Conclusion

Dans la cryptorchidie de l’adulte, l’abaissement du testicule a peu d’impact sur la fertilité masculine. Mais, vu les progrès actuels de l’assistance médicale à la procréation (AMP), le dogme d’orchidectomie systématique devant un TND diagnostiqué à l’âge adulte doit être reconsidéré.
Medicinal plants as potential male anti-infertility agents: a review
Authors: Nantia E. A. , Moundipa P. F. , Monsees T. K. , Carreau S.
Published: September 2009

For millions of couples, the inability to have a child is a personal tragedy and a large proportion of childless people are confronted with social stigmatization (blame) and personal frustration. Formerly assigned to women, infertility of a couple is nowadays equitably distributed between the two sexes. Among the methods used to treat male infertility problems, medicinal plants have been used empirically as extracts, decoctions, fractions or semi-purified compounds. These herbal products are used in the treatment of a dysfunctioning of the libido, sexual asthenia, erection, and sperm disorders. Pharmacological activities of many of these plants have been shown in vitro using cells, in vivo (on laboratory animals) and human studies. For instance, extracts of Panax ginseng, Panax quinquefolius and Lepidium meyenii have shown positive effects on sexual desire; while extracts of Astragalus membranaceus, Asparagus racemous, Withania somnifera, Andrographis paniculata and Acanthopanax senticosus improved sperm parameters. Plants provide a treatment option that is affordable and available for infertile couples, and phytotherapy is an essential form of treatment in our health system. However, herbal products are still anarchically used in many regions and countries, and a great proportion of medicinal plants used traditionally to solve male reproductive disorders have not yet been scientifically evaluated. Therefore in this review, we have summarized most of the data dealing with the effects of plant extracts on mammalian reproductive functions.
Explanation of normative declines in parents' knowledge about their adolescent children
Authors: Masche J. Gowert
Published: September 2009

This study aimed to explain why parental knowledge of adolescents' whereabouts declines with age. Such an investigation is important because previous studies have established an association between behavior problems and low levels of parental knowledge. A time‐sequential sample comprising 2415 adolescents aged 13–18 years was investigated on five annual occasions. Each year, parental knowledge declined by .10 SD. Adolescents' establishment of a private sphere (less disclosure; defiance) was the most important mediator of age effects on knowledge. Taken together, declining parental control and the establishment of a private sphere explained 37.5% of the age‐related decline in knowledge. Parental control was, however, not a significant predictor any longer when disclosure and defiance were controlled for. Results also revealed that some of the mediating variables were stronger in early‐to‐mid adolescence. Other variables appeared to slow the age‐related decline, especially in mid‐to‐late adolescence. These variables are therefore interpreted as parents' and adolescents' attempts to balance autonomy development and connectedness. If this balancing fails, adolescent behavior problems might arise along with low levels of parental knowledge early on.
Magnetic Resonance Imaging–Guided Vacuum-Assisted Breast Biopsy: An Initial Experience in a Community Hospital
Authors: Friedman Paul , Enis Sean , Pinyard Jeremy
Published: September 2009

Objective

To evaluate the effectiveness in diagnosing mammographically and sonographically occult breast lesions by using magnetic resonance imaging (MRI) guided vacuum-assisted breast biopsy in patients who presented to a community-based hospital with a newly established breast MRI program.

Methods

The records of 142 consecutive patients, median age of 55 years, who had undergone MRI-guided biopsy at our institution between July 2006 and July 2007 were reviewed. From these patients, 197 mammographically and sonographically occult lesions were biopsied at the time of discovery. The pathology was then reviewed and correlated with the MRI findings.

Results

Cancer was present and subsequently discovered in 8% of the previously occult lesions (16/197) or 11% of the women studied (16/142). Of the cancerous lesions, 56% were invasive carcinomas (9/16) and 44% were ductal carcinomas in situ (7/16). Fourteen percent of the discovered lesions (28/197) were defined as high risk and included atypical ductal hyperplasia, atypical lobular hyperplasia, lobular carcinoma in situ, and radial scar. In total, occult cancerous and high-risk lesions were discovered in 22% of the found lesions (44/197) or 31% of the women who underwent MRI-guided biopsy (44/142).

Conclusions

This study demonstrated that detection of cancerous and high-risk lesions can be significantly increased when an MRI-guided biopsy program is introduced at a community-based hospital. We believe that as radiologists gain confidence in imaging and histologic correlation, community-based hospitals can achieve similar rates of occult lesion diagnosis as those found in data emerging from academic institutions.
Fibromyalgia: From treatment to rehabilitation
Authors: Imamura Marta , Cassius David A. , Fregni Felipe
Published: September 2009

Fibromyalgia is a clinical syndrome of chronic widespread pain and reduced pain thresholds to palpation. The pathophysiology remains unknown, but there is increasing evidence that peripheral and central sensitization cause an amplification of sensory impulses that may alter pain perception in fibromyalgia patients. Interventions to treat fibromyalgia should aim at different targets simultaneously in order to reduce peripheral and central sensitization. There are both pharmacologic and non‐pharmacologic approaches with evidence for effectiveness in the treatment of fibromyalgia and its associated symptoms. Evidence from randomized trials and meta‐analyses shows that partial and short‐term improvements in fibromyalgia symptoms can be achieved with low doses of antidepressants and with physical activity such as aerobic and strengthening exercises. A multidimensional approach which emphasizes education and integration of exercise and cognitive behavior therapy improves quality of life and reduces pain, fatigue and depressive symptoms when measured on a short term basis. More recently, trials have shown the neuromodulators gabapentin and pregabalin to be effective in reducing pain and improving quality of sleep in fibromyalgia. In addition, small trials of noninvasive brain stimulation have also shown benefits in reducing pain in fibromyalgia. It is essential to keep in mind that some important clinical conditions can mimic and overlap with fibromyalgia and should always be ruled out by a complete history, physical examination and appropriate laboratory testing.
A new side opening on prolyl oligopeptidase revealed by electron microscopy
Authors: Tarragó Teresa , Martín-Benito Jaime , Sabidó Eduard , Claasen Birgit , Madurga Sergio , Gairí Margarida , Valpuesta José M. , Giralt Ernest
Published: September 2009

Prolyl oligopeptidase (POP) has gained importance as a target for the treatment of neuropsychiatric diseases and cognitive disturbances. Therefore, a variety of strategies are currently used to identify POP inhibitors. Here we performed electron microscopy (EM) studies of human POP. Our data reveal for the first time the presence of a new side opening in POP that was not observed in any of the crystallographic structures described to date. Finally, molecular dynamics, the relevant normal modes that contribute to the fluctuation of the catalytic triad residues and the algorithm CAVERN also support the existence of a new large side opening on POP.
Immediate and enduring effects of neonatal isolation on maternal behavior in rats
Authors: Kosten Therese A. , Kehoe Priscilla
Published: September 2009

Previously, we showed that neonatal isolation (1‐h isolation/day from dam, litter, and nest on PND 2–9) facilitates cocaine self‐administration and increases extracellular dopamine responses in ventral striatum after stimulant administration in adulthood. Recent studies suggest that enduring alterations in neurobehavioral responses associated with early life manipulations reflect changes in maternal behavior. Thus, we sought to determine if neonatal isolation alters maternal care and if dams with neonatal isolation experience as pups showed differential maternal care towards their pups. In Experiment 1, litters were assigned to one of three conditions: neonatal isolation, handled (5‐min separation of dam from litter), or non‐handled (no separation). Maternal behaviors were rated on PND 2–9 for 60‐min immediately following reunion of mother and litter. In Experiment 2, female rats with or without neonatal isolation experience were assigned to either the neonatal isolation or non‐handled litter condition and maternal behaviors rated. Dams of isolated and handled litters spent more time licking pups and less time picking up pups to put outside the nest than dams of non‐handled litters. Further, dams of isolated and handled vs. non‐handled litters showed less non‐maternal behaviors of burrowing and grooming. Neonatal isolation‐experienced dams with isolated litters failed to increase pup‐licking and decrease non‐maternal behaviors. Rather, these dams picked up pups to place outside the nest more than non‐handled‐experienced dams. Neonatal isolation alters maternal behavior that, in turn, may shape neurobehavioral responses of offspring including effects on maternal care. Such changes may reflect epigenetic effects resulting from changes in maternal behavior.
Descriptive epidemiology of feline upper respiratory tract disease in an animal shelter
Authors: Dinnage Julie D. , Scarlett Janet M. , Richards James R.
Published: September 2009

Upper respiratory tract disease (URTD) is common and spreads quickly in cats residing in animal shelters in the United States. Estimates of the actual incidence of URTD are sparse, yet this information is very important for welfare, economic and research purposes. In a large urban shelter in the northeastern US, 531 individual kittens, 701 litters, and 2203 adult cats were observed for signs of URTD during their stays. The median lengths of stay for adult cats and kittens were 5 and 4 days, respectively. Observations were made over a 50-week period. Approximately 1/3 exhibited signs of infectious respiratory disease. The crude incidence density estimates of URTD were 6.2, 6.7, and 5.6 cases per 100 cats per day among individual kittens, litters and adult cats, respectively. Increasing time of residence in the shelter increased risk of URTD. Using the Kaplan–Meier product limit method, the cumulative probability of developing URTD by day 7 in the shelter was approximately 32% (based on n=211) for litters, 31% (n=120) for individual kittens and 26% (n=763) for adult cats. By day 14, these cumulative probabilities had risen to 84% (n=18), 86% (n=7), and 80% (n=51) among litters, individual kittens and adult cats, respectively. The Kaplan–Meier failure function curve (probability of developing URTD overtime) for adults was significantly lower than those for litters or individual kittens (P<0.04). Among adult cats, those 11 years of age and older had a significantly higher risk of URTD compared to younger adult cats (P<0.05). Male cats (neutered and castrated) had higher URTD rates than ovariohysterectomized females, and purebred cats had a higher risk than those of mixed breeding. In this shelter, cats identified as strays were more likely to exhibit URTD than owner-surrendered cats. Affected cats spent a median of 3 more days than unaffected cats before they developed URTD. Approximately 1/3 (31.4%) of the observed individual kittens and 2/3 (61.8%) of the observed adult cats were euthanased with URTD in this shelter. Other factors such as space and behavior, especially among affected adult cats, were also cited as reasons leading to euthanasia.
Understanding control and utilizing Control Theory in the science and practice of CBT
Authors: Mansell Warren
Published: September 2009

This editorial introduces the special issue of The Cognitive Behaviour Therapist on Control Theory and CBT. The various routes through which Perceptual Control Theory (PCT) can inform CBT are explained and a range of theory, research and practice articles are introduced. Each focuses on encouraging and validating a Control Theory perspective to the clinical practice of cognitive behavioural therapies.
Heavy Element Abundances in Presolar Silicon Carbide Grains from Low-Metallicity AGB Stars
Authors: Hoppe Peter , Leitner Jan , Vollmer Christian , Gröner Elmar , Heck Philipp R. , Gallino Roberto , Amari Sachiko
Published: September 2009

Primitive meteorites contain small amounts of presolar minerals that formed in the winds of evolved stars or in the ejecta of stellar explosions. Silicon carbide is the best studied presolar mineral. Based on its isotopic compositions it was divided into distinct populations that have different origins: Most abundant are the mainstream grains which are believed to come from 1.5–3 M⊙ AGB stars of roughly solar metallicity. The rare Y and Z grains are likely to come from 1.5–3 M⊙ AGB stars as well, but with subsolar metallicities (0.3–0.5 times solar). Here we report on C and Si isotope and trace element (Zr, Ba) studies of individual, submicrometer-sized SiC grains. The most striking results are: (1) Zr and Ba concentrations are higher in Y and Z grains than in mainstream grains, with enrichments relative to Si and solar of up to 70 times (Zr) and 170 times (Ba), respectively; (2) For the Y and Z grains there is a positive correlation between Ba concentrations and amount of s-process Si. This correlation is well explained by predictions for 2–3 M⊙ AGB stars with metallicities of 0.3–0.5 times solar. This confirms low-metallicity stars as most likely stellar sources for the Y and Z grains.
Chemical Abundances of the S Star GZ Peg
Authors: Pompéia L.
Published: September 2009

The chemical compositions of stars from the Asymptotic Giant Branch are still poorly known due to the low temperatures of their atmospheres and therefore the presence of many molecular transitions hampering the analysis of atomic lines. One way to overcome this difficulty is by the study of lines in regions free from molecular contamination. We have chosen some of those regions to study the chemical abundance of the S-type star GZ Peg. Stellar parameters are derived from spectroscopic analysis and a metallicity of –0.77 dex is found. Chemical abundances of 9 elements are reported and an enhancement of s-process elements is inferred, typical to that of an S-type star.
The 13C Pocket in Low-Mass AGB Stars
Authors: Straniero O. , Cristallo S. , Gallino R.
Published: September 2009

It is well known that thermally pulsing Asymptotic Giant Branch stars with low mass play a relevant role in the chemical evolution. They have synthesized about 30% of the galactic carbon and provide an important contribution to the nucleosynthesis of heavy elements (A > 80). The relevant nucleosynthesis site is the He-rich intermediate zone (less than 10−2 M⊙), where α(2α,γ)12C reactions and slow neutron captures on seed nuclei (essentially iron) take place. A key ingredient is the interplay between nuclear processes and convective mixing. It is the partial overlap of internal and external convective zones that allows the dredge-up of the material enriched in C and heavy elements. We review the progresses made in the last 50 years in the comprehension of the s process in AGB stars, with special attention to the identification of the main neutron sources and to the particular physical conditions allowing this important nucleosynthesis.
The role of fluctuations and stress on the effective viscosity of cell aggregates
Authors: Marmottant Philippe , Mgharbel Abbas , Käfer Jos , Audren Benjamin , Rieu Jean-Paul , Vial Jean-Claude , van der Sanden Boudewijn , Marée Athanasius F. M. , Graner François , Delanoë-Ayari Hélène
Published: September 2009

Cell aggregates are a tool for in vitro studies of morphogenesis, cancer invasion, and tissue engineering. They respond to mechanical forces as a complex rather than simple liquid. To change an aggregate's shape, cells have to overcome energy barriers. If cell shape fluctuations are active enough, the aggregate spontaneously relaxes stresses (“fluctuation-induced flow”). If not, changing the aggregate's shape requires a sufficiently large applied stress (“stress-induced flow”). To capture this distinction, we develop a mechanical model of aggregates based on their cellular structure. At stress lower than a characteristic stress τ*, the aggregate as a whole flows with an apparent viscosity η*, and at higher stress it is a shear-thinning fluid. An increasing cell–cell tension results in a higher η* (and thus a slower stress relaxation time
t
c
). Our constitutive equation fits experiments of aggregate shape relaxation after compression or decompression in which irreversibility can be measured; we find
t
c
of the order of 5 h for F9 cell lines. Predictions also match numerical simulations of cell geometry and fluctuations. We discuss the deviations from liquid behavior, the possible overestimation of surface tension in parallel-plate compression measurements, and the role of measurement duration.
Evidence for biological nitrification inhibition inBrachiariapastures
Authors: Subbarao G. V. , Nakahara K. , Hurtado M. P. , Ono H. , Moreta D. E. , Salcedo A. F. , Yoshihashi A. T. , Ishikawa T. , Ishitani M. , Ohnishi-Kameyama M. , Yoshida M. , Rondon M. , Rao I. M. , Lascano C. E. , Berry W. L. , Ito O.
Published: September 2009

Nitrification, a key process in the global nitrogen cycle that generates nitrate through microbial activity, may enhance losses of fertilizer nitrogen by leaching and denitrification. Certain plants can suppress soil-nitrification by releasing inhibitors from roots, a phenomenon termed biological nitrification inhibition (BNI). Here, we report the discovery of an effective nitrification inhibitor in the root-exudates of the tropical forage grassBrachiaria humidicola(Rendle) Schweick. Named “brachialactone,” this inhibitor is a recently discovered cyclic diterpene with a unique 5-8-5-membered ring system and a γ-lactone ring. It contributed 60–90% of the inhibitory activity released from the roots of this tropical grass. Unlike nitrapyrin (a synthetic nitrification inhibitor), which affects only the ammonia monooxygenase (AMO) pathway, brachialactone appears to block both AMO and hydroxylamine oxidoreductase enzymatic pathways inNitrosomonas. Release of this inhibitor is a regulated plant function, triggered and sustained by the availability of ammonium (NH4+) in the root environment. Brachialactone release is restricted to those roots that are directly exposed to NH4+. Within 3 years of establishment,Brachiariapastures have suppressed soil nitrifier populations (determined asamoAgenes; ammonia-oxidizing bacteria and ammonia-oxidizing archaea), along with nitrification and nitrous oxide emissions. These findings provide direct evidence for the existence and active regulation of a nitrification inhibitor (or inhibitors) release from tropical pasture root systems. Exploiting the BNI function could become a powerful strategy toward the development of low-nitrifying agronomic systems, benefiting both agriculture and the environment.
Institutional challenges for mining and sustainability in Peru
Authors: Bebbington Anthony J. , Bury Jeffrey T.
Published: September 2009

Global consumption continues to generate growth in mining. In lesser developed economies, this growth offers the potential to generate new resources for development, but also creates challenges to sustainability in the regions in which extraction occurs. This context leads to debate on the institutional arrangements most likely to build synergies between mining, livelihoods, and development, and on the socio-political conditions under which such institutions can emerge. Building from a multiyear, three-country program of research projects, Peru, a global center of mining expansion, serves as an exemplar for analyzing the effects of extractive industry on livelihoods and the conditions under which arrangements favoring local sustainability might emerge. This program is guided by three emergent hypotheses in human-environmental sciences regarding the relationships among institutions, knowledge, learning, and sustainability. The research combines in-depth and comparative case study analysis, and uses mapping and spatial analysis, surveys, in-depth interviews, participant observation, and our own direct participation in public debates on the regulation of mining for development. The findings demonstrate the pressures that mining expansion has placed on water resources, livelihood assets, and social relationships. These pressures are a result of institutional conditions that separate the governance of mineral expansion, water resources, and local development, and of relationships of power that prioritize large scale investment over livelihood and environment. A further problem is the poor communication between mining sector knowledge systems and those of local populations. These results are consistent with themes recently elaborated in sustainability science.
Reticulon 4B (Nogo-B) is necessary for macrophage infiltration and tissue repair
Authors: Yu Jun , Fernández-Hernando Carlos , Suarez Yajaira , Schleicher Michael , Hao Zhengrong , Wright Paulette L. , DiLorenzo Annarita , Kyriakides Themis R. , Sessa William C.
Published: September 2009

Blood vessel formation during ischemia and wound healing requires coordination of the inflammatory response with genes that regulate blood vessel assembly. Here we show that the reticulon family member 4B, aka Nogo-B, is upregulated in response to ischemia and is necessary for blood flow recovery secondary to ischemia and wound healing. Mice lacking Nogo-B exhibit reduced arteriogenesis and angiogenesis that are linked to a decrease in macrophage infiltration and inflammatory gene expression in vivo. Bone marrow-derived macrophages isolated from Nogo knock-out mice have reduced spreading and chemotaxis due to impaired Rac activation. Bone marrow reconstitution experiments show that Nogo in myeloid cells is necessary to promote macrophage homing and functional recovery after limb ischemia. Thus, endogenous Nogo coordinates macrophage-mediated inflammation with arteriogenesis, wound healing, and blood flow control.
Malignant cell-derived PlGF promotes normalization and remodeling of the tumor vasculature
Authors: Hedlund Eva-Maria , Hosaka Kayoko , Zhong Zhaodong , Cao Renhai , Cao Yihai
Published: September 2009

Vascular functions of PlGF remain poorly understood and controversial. Here, we show that tumor cell-derived PlGF-1 and PlGF-2 displayed significant remodeling effects on the tumor vasculature, leading to a normalized vascular phenotype and improved functions against leakage. In two murine tumor models, that is, T241 fibrosarcoma and Lewis lung carcinoma, stable expression of PlGF-1 and PlGF-2 in tumor cells resulted in significant reduction of tumor microvascular density and branch formation. Markedly, the vasculature in PlGF-expressing tumors consisted of relatively large-diameter microvessels with substantial improvement of pericyte coverage. Similarly, PlGF-induced vascular normalization and remodeling were also observed in a spontaneous human choriocarcinoma that expressed endogenous PlGF. Our findings shed light on functions of PlGF as a vascular remodeling factor that normalizes the tumor vasculature and thus may have conceptual implications of cancer therapy.
Targeting proteins to distinct subcellular compartments reveals unique requirements for MHC class I and II presentation
Authors: Belizaire Roger , Unanue Emil R.
Published: September 2009

Peptides derived from exogenous proteins are presented by both MHC class I and II. Despite extensive study, the features of the endocytic pathway that mediate cross-presentation of exogenous antigens on MHC class I are not entirely understood and difficult to generalize to all proteins. Here, we used dendritic cells and macrophages to examine MHC class I and II presentation of hen egg-white lysozyme (HEL) in different forms, soluble and liposome encapsulated. Soluble HEL or HEL targeted to a late endosomal compartment only allowed for MHC class II presentation, in a process that was blocked by chloroquine and a cathepsin S (CatS) inhibitor; brefeldin A (BFA) also blocked presentation, indicating a requirement for nascent MHC class II. In contrast, liposome-encapsulated HEL targeted to early endosomes entered the MHC class I and II presentation pathways. Cross-presentation of HEL in early endosomal liposomes had several unique features: it was markedly increased by BFA and by blockade of the proteasome or CatS activity, it occurred independently of the transporter associated with antigen processing but required an MHC class I surface-stabilizing peptide, and it was inhibited by chloroquine. Remarkably, chloroquine facilitated MHC class I cross-presentation of soluble HEL and HEL in late endosomal liposomes. Altogether, MHC class I and II presentation of HEL occurred through pathways having distinct molecular and proteolytic requirements. Moreover, MHC class I sampled antigenic peptides from various points along the endocytic route.
IL-18 binding protein-expressing mesenchymal stem cells improve myocardial protection after ischemia or infarction
Authors: Wang Meijing , Tan Jiangning , Wang Yue , Meldrum Kirstan K. , Dinarello Charles A. , Meldrum Daniel R.
Published: September 2009

IL-18 is a proinflammatory cytokine known to cause tissue injury by inducing inflammation and cell death. Increased levels of IL-18 are associated with myocardial injury after ischemia or infarction. IL-18-binding protein (IL-18BP), the naturally occurring inhibitor of IL-18 activity, decreases the severity of inflammation in response to injury. In the present study, mesenchymal stem cells (MSCs) derived from mice transgenic for over expression of human IL-18BP were tested in rat models of global myocardial ischemia and acute myocardial infarction. Improved myocardial function is associated with production of VEGF, and in vitro, IL-18BP MSCs secreted higher levels of constitutive VEGF compared to wild-type MSCs. Whereas IL-18 increased cell death and reduced VEGF in wild-type MSCs, IL-18BP MSCs were protected. In an isolated heart model, intracoronary infusion of IL-18BP MSCs before ischemia increased postischemic left ventricular (LV) developed pressure to 79.5 ± 9.47 mmHg compared to 59.3 ± 7.8 mmHg in wild-type MSCs and 37.8 ± 5 mmHg in the vehicle group. Similarly, using a coronary artery ligation model, intramyocardial injection of IL-18BP MSCs improved LV ejection fraction to 67.8 ± 1.76% versus wild-type MSCs (57.4 ± 1.33%) and vehicle (39.2 ± 2.07%), increased LV fractional shortening 1.25-fold over wild-type MSCs and 1.95-fold over vehicle, decreased infarct size to 38.8 ± 2.16% compared to 46.4 ± 1.92% in wild-type MSCs and 60.7 ± 2.2% in vehicle, reduced adverse ventricular remodeling, increased myocardial VEGF production, and decreased IL-6 levels. This study provides the concept that IL-18BP genetically modified stem cells improve cardioprotection over that observed with unmodified stem cells.
Enzyme millisecond conformational dynamics do not catalyze the chemical step
Authors: Pisliakov Andrei V. , Cao Jie , Kamerlin Shina C. L. , Warshel Arieh
Published: September 2009

The idea that enzymes catalyze reactions by dynamical coupling between the conformational motions and the chemical coordinates has recently attracted major experimental and theoretical interest. However, experimental studies have not directly established that the conformational motions transfer energy to the chemical coordinate, and simulating enzyme catalysis on the relevant timescales has been impractical. Here, we introduce a renormalization approach that transforms the energetics and dynamics of the enzyme to an equivalent low-dimensional system, and allows us to simulate the dynamical coupling on a ms timescale. The simulations establish, by means of several independent approaches, that the conformational dynamics is not remembered during the chemical step and does not contribute significantly to catalysis. Nevertheless, the precise nature of this coupling is a question of great importance.
Appraising the apoptotic mimicry model and the role of phospholipids for poxvirus entry
Authors: Laliberte Jason P. , Moss Bernard
Published: September 2009

Entry of vaccinia virus (VACV) into cells occurs by fusion with the plasma membrane and via a low pH-dependent endosomal pathway, presumably involving unidentified cellular receptors. In addition to ≈25 viral proteins, the membrane of VACV mature virions contains several phospholipids including phosphatidylserine (PS). A recent model posits that PS flags virions as apoptotic debris to activate a common cellular uptake pathway to gain cell entry, perhaps through an interaction with a PS-specific cell surface receptor. To evaluate the apoptotic mimicry model, we reconstituted the membrane of detergent-extracted virions with several different phospholipids. Although the ability of the L-stereoisomer of PS to reconstitute infectivity was confirmed, the nonbiologically relevant D-stereoisomer of PS, and phosphatidylglycerol, which are not normally present in the virion membrane, functioned as well. Regardless of which phospholipid reconstituted infectivity, virus entry was inhibited by a neutralizing monoclonal antibody to a virion surface protein and by the drugs blebbistatin and bafilomycin A1, suggesting that in each case virus uptake was specific and occurred by a similar mechanism involving macropinocytosis and a low-pH endocytic pathway. Lipid-reconstituted and nonreconstituted, membrane-extracted virions were equally capable of binding to cells. However, the physical association of phospholipids with virus particles during membrane reconstitution correlated directly with rescue of particle infectivity and cell entry capability. Our results support a role for PS in poxvirus entry, but demonstrate that other phospholipids, not known to signal uptake of apoptotic debris, can function similarly.
Cargo sorting into multivesicular bodies in vitro
Authors: Tran John H. , Chen Ching-Jen , Emr Scott , Schekman Randy
Published: September 2009

Genetic studies have identified a number of proteins required for the internalization of biosynthetic and endocytic cargo proteins transported to the multivesicular body (MVB). We have developed a cell-free reaction that recapitulates the internalization of a yeast biosynthetic membrane cargo protein, carboxypeptidase S (CPS), into the interior of an endosome. A recombinant form of CPS containing a biotinylation site from an
Escherichia coli
protein is accumulated in a
vps27
yeast mutant blocked in the MVB internalization event. Endosomes isolated from the
vps27
mutant are exposed to
E. coli
biotin ligase, which acts on only those CPS molecules with a cytosol-exposed N-terminal domain. Internalization of biotin-tagged CPS is measured by the detection of trypsin-inaccessible, membrane-protected species. Biotinylated CPS internalization requires ATP and functional forms of Vps27p and Vps4p and depends on the availability of an exposed lysine residue critical for CPS ubiquitylation.
History, a Useful “Science” for Management? From Polemics to Controversies
Authors: Godelier Eric
Published: September 2009

The aim of this essay is to analyze the way management sciences and practices use history or at least the kind of research which they define as history. This reflection will lead to discussing the possibility and the opportunity that an historical approach might have in creating management knowledge, especially “workable” know-how. A quick look at present-day exchanges between the two communities could lead us to the conclusion that there were tensions in the past that have not entirely evaporated. Might they explain the relative modesty of the dialogue, at least in France?
Stable isotope analysis of marine feeding signatures of Atlantic salmon in the North Atlantic
Authors: Dempson J. Brian , Braithwaite Victoria A. , Doherty Denis , Power Michael
Published: September 2009

Dempson, J. B., Braithwaite, V. A., Doherty, D., and Power, M. 2010. Stable isotope analysis of marine feeding signatures of Atlantic salmon in the North Atlantic. – ICES Journal of Marine Science, 67: 52–61. Differences in the marine feeding of three geographically distinct populations of Atlantic salmon (Salmo salar) in the North Atlantic (Conne River, Newfoundland; Koksoak River, Ungava Bay, Québec; River Erne, northwest Ireland) were examined using analyses of stable isotopes of carbon and nitrogen (δ13C and δ15N) and contrasted with isotope signatures obtained from a sample of salmon of unknown origin captured in the Labrador Sea. Although the overall range of δ13C and δ15N values (δ13C: from −22.42 to −19.37; δ15N: from 10.70 to 13.38) was similar to that reported by others, significant differences were found among populations and between different sea-age life-history groups. Reported differences in marine feeding between populations from the Northeast and Northwest Atlantic corroborated the stable isotope results. A surrogate measure of lipid content, the C:N ratio, was also compared among 1-sea-winter salmon. The highest levels were associated with the Koksoak River, suggesting that Subarctic populations may require higher energy reserves to contend with their longer migrations and more-severe environmental conditions.
Towards a precautionary approach to managing Canada's commercial harp seal hunt
Authors: Leaper Russell , Lavigne David M. , Corkeron Peter , Johnston David W.
Published: September 2009

Leaper, R., Lavigne, D. M., Corkeron, P., and Johnston, D. W. 2010. Towards a precautionary approach to managing Canada's commercial harp seal hunt. – ICES Journal of Marine Science, 67: 316–320. The Canadian government's approach to the management of its commercial harp seal hunt is compared with other precautionary approaches developed for setting anthropogenic removal limits for marine mammal populations. For Canada's harp seal hunt, the current management strategy has not been fully specified or tested, and its robustness to changes in biological parameters, uncertainty in input data and environmental variability, remains unknown. As such, the management approach cannot be considered precautionary and there is a substantial, but not quantified, probability that it will not meet its objectives. There is an urgent need for a fully specified and rigorously tested management procedure, and steps towards this are suggested that should reduce the risks associated with the current approach.
Surgery for Lone Atrial Fibrillation: Present State-of-the-Art
Authors: Shen Jeanne , Bailey Marci , Damiano Ralph J.
Published: September 2009

For 2 decades, the cut-and-sew Cox-Maze III procedure was the gold standard for the surgical treatment of atrial fibrillation (AF) and proved to be effective at curing lone AF and preventing its most dreaded complication, stroke. However, this procedure was not widely adopted because of its complexity and technical difficulty. During the past 5 to 10 years, the introduction of new ablation technology has led to the development of the Cox-Maze IV procedure, as well as, more limited lesion sets, with the ultimate goal of performing a minimally invasive lesion set on the beating heart, without the need for cardiopulmonary bypass. This review summarizes the current state of the art and future directions in the surgical treatment of lone AF. The hope is that as we learn more about the mechanisms of AF and develop preoperative diagnostic technologies capable of precisely locating the areas responsible for AF, it will become possible to tailor specific lesion sets and ablation modalities to individual patients, making the surgical treatment of lone AF available to a larger population of patients.
Early Results of Edge-to-Edge Alfieri Mitral Repair via Right Mini-Thoracotomy in 68 Consecutive Patients
Authors: Glower Donald D. , Desai Bhargavi , Mackensen G. Burkhard
Published: September 2009

Objective

To examine early outcomes of mitral valve repair using Alfieri repair via a right mini-thoracotomy approach.

Methods

Records were examined in 68 consecutive patients undergoing Alfieri mitral repair via 6 cm right mini-thoracotomy. Most repairs were performed under cardioplegic arrest, using percutaneous femoral cannulation and direct aortic cannulation through the right first intercostal space. All patients without hypertrophic cardiomyopathy received rigid ring annuloplasty. The indications for Alfieri repair were extensive prolapse with ring size at least 30 mm.

Results

Mean age was 56 ± 13 (range, 20–80). Mitral disease etiology was Barlow disease in 17 of 68 (25%) patients and myxomatous disease in 47 of 68 (69%). Concurrent procedures were performed in 29 of 68 (43%) patients. Median ring size was 34 mm. Despite extensive leaflet disease, 59 of 68 (87%) patients were repaired without leaflet resection. Chord pairs were inserted on the posterior leaflet in 18 of 68 (26%) patients and anterior leaflet in four patients. There were no 30-day or late deaths. Residual intraoperative mitral regurgitation was absent in 54 of 68 (79%) patients and trace in the remainder. Local echocardiography follow-up at a mean of 99 days showed median residual regurgitation to be trace. Only two patients developed moderate regurgitation. Mean mitral gradient at follow-up was 4 ± 2 mm Hg. Local follow-up showed 28 of 39 (72%) patients to be New York Heart Association class I.

Conclusions

An edge-to-edge Alfieri repair via mini-thoracotomy can provide excellent short-term results in selected patients with complex myxomatous mitral disease when minimizing the need for leaflet resection.
The Effect of Combined Clopidogrel and Aspirin Therapy after Off-Pump Coronary Surgery
Authors: Mujanovic Emir , Nurkic Midhat , Caluk Jasmin , Terzic Ibrahim , Kabil Emir , Bergsland Jacob
Published: September 2009

Objective

The purpose of this randomized study was to evaluate the effect on graft patency by adding clopidogrel to aspirin in off-pump coronary artery bypass (OPCAB) grafting and the possible side effects of such therapy.

Methods

Twenty patients who underwent standard OPCAB through median sternotomy were randomized immediately after surgery in two groups. Patients in group A (n = 10) received 100 mg of aspirin starting preoperatively, continuing indefinitely. Patients in group B received 100 mg of aspirin and, in addition, 75 mg of clopidogrel starting immediately after the operation and for 3 months. Postoperative bleeding and other perioperative parameters were compared. Angiography was repeated 3 months after surgery to determine the patency and quality of grafts.

Results

Preoperative risk factors were similar in the two groups. There was no significant difference in average number of distal anastomosis (P = 0.572), operation time (P = 0.686), postoperative bleeding (P = 0.256), ventilation time (P = 0.635), and intensive care unit stay (P = 0.065). Length of stay was shorter in group B (P = 0.024). There was no postoperative complication in either groups. Eight of 27 grafts in group A and 2 of 29 grafts in group B (P = 0.037) were occluded at the time of control angiography.

Conclusions

Early administration of a combined regimen of clopidogrel and aspirin after OPCAB grafting is not associated with increased postoperative bleeding or other major complications. Despite the small number of patients in this study and small number of examined grafts, the results suggest that the addition of clopidogrel may increase graft patency after OPCAB grafting.
The Role of Thromboelastography in Directing Blood Product Usage in Infant Open Heart Surgery
Authors: Mendeloff Eric N. , Glenn George F. , Tavakolian Paul , Lin Eugene , Leonard Allison , Prince Syma L. , Herbert Morley A.
Published: September 2009

Objective

Thromboelastography (TEG) measures the dynamics of clot formation in whole blood and provides data that can guide specific blood component therapy. This study analyzed whether the implementation of TEG affected blood product utilization and overall hemostasis in infants (6 months and younger) undergoing open heart surgery.

Methods

TEG values measured include R (time to fibrin formation), angle (fibrinogen formation), and MA (platelet function). Blood product usage, TEG values, and operative parameters were collected during surgery on 112 consecutive infants (66 acyanotic) undergoing open heart surgery within the first 6 months of life. Controls consisted of chart data on 70 consecutive patients (57 acyanotic) undergoing the same surgical procedures before implementation of TEG (pre-TEG).

Results

Using TEG, the pattern of blood product utilization changed. Compared with the pre-TEG era, TEG era patients demonstrated a significant increase in fresh frozen plasma usage intraoperatively (4.74 vs. 1.83 mL/kg; P < 0.001) and reduced postoperative use of platelets (1.69 vs. 3.74 mL/kg; P = 0.006) and cryoprecipitate (0.89 vs. 1.95 mL/kg; P = 0.149). Chest tube drainage was significantly reduced at 1, 2, and 24 hours in the TEG group. TEG angle and MA measurements suggest that fibrinogen and platelets of cyanotic patients are more sensitive to hemodilution than the acyanotic patients.

Conclusions

TEG allows for proactive, goal-directed blood component therapy with improved postoperative hemostasis in infants undergoing cardiopulmonary bypass.
Off-Pump Positioning of a Conventional Aortic Valve Prosthesis through the Left Ventricular Apex with the Universal Cardiac Introducer under Sole Ultrasound Guidance, in the Pig
Authors: Guiraudon Gerard M. , Jones Douglas L. , Bainbridge Daniel , Peters Terence M.
Published: September 2009

Objective

To test an alternative to catheter and open-heart techniques, by documenting the feasibility of implanting an unmodified mechanical aortic valve (AoV) in the off pump, beating heart using the universal cardiac introducer (UCI) attached to the left ventricular (LV) apex.

Methods

In six pigs, the LV apex was exposed by a median sternotomy. The UCI was attached to the apex. A 12-mm punching tool (punch), introduced through the UCI, was used to create a cylindrical opening through the apex. Then, the AoV, secured to a holder, was introduced into the LV, using transesophageal echocardiographic, guided through the apical LV opening, navigated into the LV outflow tract, and positioned within the aortic annulus. Trans-esophageal echocardiographic guidance was useful for navigation and positioning by superimposing the aortic annulus and prosthetic ring while Doppler imaging verified preserved prosthetic function and absence of perivalvular leaks. The valve function and hemodynamics were observed before termination for macroscopic evaluation.

Results

The punch produced a clean opening without fragmentation or myocardial embolization. During advancement of the mechanical AoV, there were no arrhythmias, mitral valve dysfunctions, evidence of myocardial ischemia, or hemodynamic instability. The AoVs were well seated over the annulus, without obstructing the coronaries or contact with the conduction system. The ring of AoVs was well circumscribed by the aortic annulus.

Conclusions

This study documented the feasibility of positioning a mechanical AoV on the closed, beating heart. These results should encourage the development of adjunct technologies to deliver current tissue or mechanical AoV with minimal side effects.